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   <h1 id="Lucene_Net_Index_IndexWriter" data-uid="Lucene.Net.Index.IndexWriter" class="text-break">Class IndexWriter
   </h1>
   <div class="markdown level0 summary"><p>An <a class="xref" href="Lucene.Net.Index.IndexWriter.html">IndexWriter</a> creates and maintains an index.</p>
 </div>
   <div class="markdown level0 conceptual"></div>
   <div class="inheritance">
     <h5>Inheritance</h5>
     <div class="level0"><span class="xref">System.Object</span></div>
     <div class="level1"><span class="xref">IndexWriter</span></div>
   </div>
   <div classs="implements">
     <h5>Implements</h5>
     <div><span class="xref">System.IDisposable</span></div>
     <div><a class="xref" href="Lucene.Net.Index.ITwoPhaseCommit.html">ITwoPhaseCommit</a></div>
   </div>
   <div class="inheritedMembers">
     <h5>Inherited Members</h5>
     <div>
       <span class="xref">System.Object.Equals(System.Object)</span>
     </div>
     <div>
       <span class="xref">System.Object.Equals(System.Object, System.Object)</span>
     </div>
     <div>
       <span class="xref">System.Object.GetHashCode()</span>
     </div>
     <div>
       <span class="xref">System.Object.GetType()</span>
     </div>
     <div>
       <span class="xref">System.Object.MemberwiseClone()</span>
     </div>
     <div>
       <span class="xref">System.Object.ReferenceEquals(System.Object, System.Object)</span>
     </div>
     <div>
       <span class="xref">System.Object.ToString()</span>
     </div>
   </div>
   <h6><strong>Namespace</strong>: <a class="xref" href="Lucene.Net.Index.html">Lucene.Net.Index</a></h6>
   <h6><strong>Assembly</strong>: Lucene.Net.dll</h6>
   <h5 id="Lucene_Net_Index_IndexWriter_syntax">Syntax</h5>
   <div class="codewrapper">
     <pre><code class="lang-csharp hljs">public class IndexWriter : IDisposable, ITwoPhaseCommit</code></pre>
   </div>
   <h5 id="Lucene_Net_Index_IndexWriter_remarks"><strong>Remarks</strong></h5>
   <div class="markdown level0 remarks"><p>The <a class="xref" href="Lucene.Net.Index.OpenMode.html">OpenMode</a> option on
 <a class="xref" href="Lucene.Net.Index.IndexWriterConfig.html#Lucene_Net_Index_IndexWriterConfig_OpenMode">OpenMode</a> determines
 whether a new index is created, or whether an existing index is
 opened. Note that you can open an index with <a class="xref" href="Lucene.Net.Index.OpenMode.html#Lucene_Net_Index_OpenMode_CREATE">CREATE</a>
 even while readers are using the index. The old readers will
 continue to search the &quot;point in time&quot; snapshot they had opened,
 and won&apos;t see the newly created index until they re-open. If
 <a class="xref" href="Lucene.Net.Index.OpenMode.html#Lucene_Net_Index_OpenMode_CREATE_OR_APPEND">CREATE_OR_APPEND</a> is used <a class="xref" href="Lucene.Net.Index.IndexWriter.html">IndexWriter</a> will create a
 new index if there is not already an index at the provided path
 and otherwise open the existing index.</p>

 <p>In either case, documents are added with <a class="xref" href="Lucene.Net.Index.IndexWriter.html#Lucene_Net_Index_IndexWriter_AddDocument_System_Collections_Generic_IEnumerable_Lucene_Net_Index_IIndexableField__">AddDocument(IEnumerable&lt;IIndexableField&gt;)</a>
 and removed with <a class="xref" href="Lucene.Net.Index.IndexWriter.html#Lucene_Net_Index_IndexWriter_DeleteDocuments_Lucene_Net_Index_Term_">DeleteDocuments(Term)</a> or
 <a class="xref" href="Lucene.Net.Index.IndexWriter.html#Lucene_Net_Index_IndexWriter_DeleteDocuments_Lucene_Net_Search_Query_">DeleteDocuments(Query)</a>. A document can be updated with
 <a class="xref" href="Lucene.Net.Index.IndexWriter.html#Lucene_Net_Index_IndexWriter_UpdateDocument_Lucene_Net_Index_Term_System_Collections_Generic_IEnumerable_Lucene_Net_Index_IIndexableField__">UpdateDocument(Term, IEnumerable&lt;IIndexableField&gt;)</a> (which just deletes
 and then adds the entire document). When finished adding, deleting
 and updating documents, <a class="xref" href="Lucene.Net.Index.IndexWriter.html#Lucene_Net_Index_IndexWriter_Dispose">Dispose()</a> should be called.</p>

 <p><a name="flush"></a>
 <p>These changes are buffered in memory and periodically
 flushed to the <a class="xref" href="Lucene.Net.Store.Directory.html">Directory</a> (during the above method
 calls). A flush is triggered when there are enough added documents
 since the last flush. Flushing is triggered either by RAM usage of the
 documents (see <a class="xref" href="Lucene.Net.Index.LiveIndexWriterConfig.html#Lucene_Net_Index_LiveIndexWriterConfig_RAMBufferSizeMB">RAMBufferSizeMB</a>) or the
 number of added documents (see <a class="xref" href="Lucene.Net.Index.LiveIndexWriterConfig.html#Lucene_Net_Index_LiveIndexWriterConfig_MaxBufferedDocs">MaxBufferedDocs</a>).
 The default is to flush when RAM usage hits
 <a class="xref" href="Lucene.Net.Index.IndexWriterConfig.html#Lucene_Net_Index_IndexWriterConfig_DEFAULT_RAM_BUFFER_SIZE_MB">DEFAULT_RAM_BUFFER_SIZE_MB</a> MB. For
 best indexing speed you should flush by RAM usage with a
 large RAM buffer. Additionally, if <a class="xref" href="Lucene.Net.Index.IndexWriter.html">IndexWriter</a> reaches the configured number of
 buffered deletes (see <a class="xref" href="Lucene.Net.Index.LiveIndexWriterConfig.html#Lucene_Net_Index_LiveIndexWriterConfig_MaxBufferedDeleteTerms">MaxBufferedDeleteTerms</a>)
 the deleted terms and queries are flushed and applied to existing segments.
 In contrast to the other flush options <a class="xref" href="Lucene.Net.Index.LiveIndexWriterConfig.html#Lucene_Net_Index_LiveIndexWriterConfig_RAMBufferSizeMB">RAMBufferSizeMB</a> and
 <a class="xref" href="Lucene.Net.Index.LiveIndexWriterConfig.html#Lucene_Net_Index_LiveIndexWriterConfig_MaxBufferedDocs">MaxBufferedDocs</a>, deleted terms
 won&apos;t trigger a segment flush. Note that flushing just moves the
 internal buffered state in <a class="xref" href="Lucene.Net.Index.IndexWriter.html">IndexWriter</a> into the index, but
 these changes are not visible to <a class="xref" href="Lucene.Net.Index.IndexReader.html">IndexReader</a> until either
 <a class="xref" href="Lucene.Net.Index.IndexWriter.html#Lucene_Net_Index_IndexWriter_Commit">Commit()</a> or <a class="xref" href="Lucene.Net.Index.IndexWriter.html#Lucene_Net_Index_IndexWriter_Dispose">Dispose()</a> is called.  A flush may
 also trigger one or more segment merges which by default
 run with a background thread so as not to block the
 addDocument calls (see <a href="#mergePolicy">below</a>
 for changing the <span class="xref">Lucene.Net.Index.IndexWriter.mergeScheduler</span>).</p></p>
 <p>Opening an <a class="xref" href="Lucene.Net.Index.IndexWriter.html">IndexWriter</a> creates a lock file for the directory in use. Trying to open
 another <a class="xref" href="Lucene.Net.Index.IndexWriter.html">IndexWriter</a> on the same directory will lead to a
 <a class="xref" href="Lucene.Net.Store.LockObtainFailedException.html">LockObtainFailedException</a>. The <a class="xref" href="Lucene.Net.Store.LockObtainFailedException.html">LockObtainFailedException</a>
 is also thrown if an <a class="xref" href="Lucene.Net.Index.IndexReader.html">IndexReader</a> on the same directory is used to delete documents
 from the index.</p>

 <p><a name="deletionPolicy"></a>
 <p>Expert: <a class="xref" href="Lucene.Net.Index.IndexWriter.html">IndexWriter</a> allows an optional
 <a class="xref" href="Lucene.Net.Index.IndexDeletionPolicy.html">IndexDeletionPolicy</a> implementation to be
 specified.  You can use this to control when prior commits
 are deleted from the index.  The default policy is
 <a class="xref" href="Lucene.Net.Index.KeepOnlyLastCommitDeletionPolicy.html">KeepOnlyLastCommitDeletionPolicy</a> which removes all prior
 commits as soon as a new commit is done (this matches
 behavior before 2.2).  Creating your own policy can allow
 you to explicitly keep previous &quot;point in time&quot; commits
 alive in the index for some time, to allow readers to
 refresh to the new commit without having the old commit
 deleted out from under them.  This is necessary on
 filesystems like NFS that do not support &quot;delete on last
 close&quot; semantics, which Lucene&apos;s &quot;point in time&quot; search
 normally relies on. </p></p>
 <p><a name="mergePolicy"></a> <p>Expert:
 <a class="xref" href="Lucene.Net.Index.IndexWriter.html">IndexWriter</a> allows you to separately change
 the <span class="xref">Lucene.Net.Index.IndexWriter.mergePolicy</span> and the <span class="xref">Lucene.Net.Index.IndexWriter.mergeScheduler</span>.
 The <span class="xref">Lucene.Net.Index.IndexWriter.mergePolicy</span> is invoked whenever there are
 changes to the segments in the index.  Its role is to
 select which merges to do, if any, and return a
 <a class="xref" href="Lucene.Net.Index.MergePolicy.MergeSpecification.html">MergePolicy.MergeSpecification</a> describing the merges.
 The default is <a class="xref" href="Lucene.Net.Index.LogByteSizeMergePolicy.html">LogByteSizeMergePolicy</a>.  Then, the
 <a class="xref" href="Lucene.Net.Index.MergeScheduler.html">MergeScheduler</a> is invoked with the requested merges and
 it decides when and how to run the merges.  The default is
 <a class="xref" href="Lucene.Net.Index.ConcurrentMergeScheduler.html">ConcurrentMergeScheduler</a>. </p></p>
 <p><a name="OOME"></a><p><strong>NOTE</strong>: if you hit an
 <span class="xref">System.OutOfMemoryException</span> then <a class="xref" href="Lucene.Net.Index.IndexWriter.html">IndexWriter</a> will quietly record this
 fact and block all future segment commits.  This is a
 defensive measure in case any internal state (buffered
 documents and deletions) were corrupted.  Any subsequent
 calls to <a class="xref" href="Lucene.Net.Index.IndexWriter.html#Lucene_Net_Index_IndexWriter_Commit">Commit()</a> will throw an
 <span class="xref">System.InvalidOperationException</span>.  The only course of action is to
 call <a class="xref" href="Lucene.Net.Index.IndexWriter.html#Lucene_Net_Index_IndexWriter_Dispose">Dispose()</a>, which internally will call
 <a class="xref" href="Lucene.Net.Index.IndexWriter.html#Lucene_Net_Index_IndexWriter_Rollback">Rollback()</a>, to undo any changes to the index since the
 last commit.  You can also just call <a class="xref" href="Lucene.Net.Index.IndexWriter.html#Lucene_Net_Index_IndexWriter_Rollback">Rollback()</a>
 directly.</p></p>
 <p><a name="thread-safety"></a><p><strong>NOTE</strong>:
 <a class="xref" href="Lucene.Net.Index.IndexWriter.html">IndexWriter</a> instances are completely thread
 safe, meaning multiple threads can call any of its
 methods, concurrently.  If your application requires
 external synchronization, you should <strong>not</strong>
 synchronize on the <a class="xref" href="Lucene.Net.Index.IndexWriter.html">IndexWriter</a> instance as
 this may cause deadlock; use your own (non-Lucene) objects
 instead. </p></p>
 <p><strong>NOTE</strong>: If you call
 <span class="xref">System.Threading.Thread.Interrupt</span> on a thread that&apos;s within
 <a class="xref" href="Lucene.Net.Index.IndexWriter.html">IndexWriter</a>, <a class="xref" href="Lucene.Net.Index.IndexWriter.html">IndexWriter</a> will try to catch this (eg, if
 it&apos;s in a Wait() or <span class="xref">System.Threading.Thread.Sleep(System.Int32)</span>), and will then throw
 the unchecked exception <span class="xref">System.Threading.ThreadInterruptedException</span>
 and <strong>clear</strong> the interrupt status on the thread.</p>
 </div>
   <h3 id="constructors">Constructors
   </h3>
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   <a id="Lucene_Net_Index_IndexWriter__ctor_" data-uid="Lucene.Net.Index.IndexWriter.#ctor*"></a>
   <h4 id="Lucene_Net_Index_IndexWriter__ctor_Lucene_Net_Store_Directory_Lucene_Net_Index_IndexWriterConfig_" data-uid="Lucene.Net.Index.IndexWriter.#ctor(Lucene.Net.Store.Directory,Lucene.Net.Index.IndexWriterConfig)">IndexWriter(Directory, IndexWriterConfig)</h4>
   <div class="markdown level1 summary"><p>Constructs a new <a class="xref" href="Lucene.Net.Index.IndexWriter.html">IndexWriter</a> per the settings given in <code data-dev-comment-type="paramref" class="paramref">conf</code>.
 If you want to make &quot;live&quot; changes to this writer instance, use
 <a class="xref" href="Lucene.Net.Index.IndexWriter.html#Lucene_Net_Index_IndexWriter_Config">Config</a>.</p>
 <p><p>
 <strong>NOTE:</strong> after ths writer is created, the given configuration instance
 cannot be passed to another writer. If you intend to do so, you should
 <a class="xref" href="Lucene.Net.Index.IndexWriterConfig.html#Lucene_Net_Index_IndexWriterConfig_Clone">Clone()</a> it beforehand.</p>
 </div>
   <div class="markdown level1 conceptual"></div>
   <h5 class="decalaration">Declaration</h5>
   <div class="codewrapper">
     <pre><code class="lang-csharp hljs">public IndexWriter(Directory d, IndexWriterConfig conf)</code></pre>
   </div>
   <h5 class="parameters">Parameters</h5>
   <table class="table table-bordered table-striped table-condensed">
     <thead>
       <tr>
         <th>Type</th>
         <th>Name</th>
         <th>Description</th>
       </tr>
     </thead>
     <tbody>
       <tr>
         <td><a class="xref" href="Lucene.Net.Store.Directory.html">Directory</a></td>
         <td><span class="parametername">d</span></td>
         <td><p>the index directory. The index is either created or appended
 according <a class="xref" href="Lucene.Net.Index.IndexWriterConfig.html#Lucene_Net_Index_IndexWriterConfig_OpenMode">OpenMode</a>. </p>
 </td>
       </tr>
       <tr>
         <td><a class="xref" href="Lucene.Net.Index.IndexWriterConfig.html">IndexWriterConfig</a></td>
         <td><span class="parametername">conf</span></td>
         <td><p>the configuration settings according to which <a class="xref" href="Lucene.Net.Index.IndexWriter.html">IndexWriter</a> should
 be initialized. </p>
 </td>
       </tr>
     </tbody>
   </table>
   <h5 class="exceptions">Exceptions</h5>
   <table class="table table-bordered table-striped table-condensed">
     <thead>
       <tr>
         <th>Type</th>
         <th>Condition</th>
       </tr>
     </thead>
     <tbody>
       <tr>
         <td><span class="xref">System.IO.IOException</span></td>
         <td><p>if the directory cannot be read/written to, or if it does not
 exist and <a class="xref" href="Lucene.Net.Index.IndexWriterConfig.html#Lucene_Net_Index_IndexWriterConfig_OpenMode">OpenMode</a> is
 <a class="xref" href="Lucene.Net.Index.OpenMode.html#Lucene_Net_Index_OpenMode_APPEND">APPEND</a> or if there is any other low-level
 IO error </p>
 </td>
       </tr>
     </tbody>
   </table>
   <h3 id="fields">Fields
   </h3>
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   </span>
   <h4 id="Lucene_Net_Index_IndexWriter_MAX_TERM_LENGTH" data-uid="Lucene.Net.Index.IndexWriter.MAX_TERM_LENGTH">MAX_TERM_LENGTH</h4>
   <div class="markdown level1 summary"><p>Absolute hard maximum length for a term, in bytes once
 encoded as UTF8.  If a term arrives from the analyzer
 longer than this length, an
 <span class="xref">System.ArgumentException</span> is thrown
 and a message is printed to <span class="xref">Lucene.Net.Index.IndexWriter.infoStream</span>, if set (see
 <a class="xref" href="Lucene.Net.Index.IndexWriterConfig.html#Lucene_Net_Index_IndexWriterConfig_SetInfoStream_Lucene_Net_Util_InfoStream_">SetInfoStream(InfoStream)</a>).</p>
 </div>
   <div class="markdown level1 conceptual"></div>
   <h5 class="decalaration">Declaration</h5>
   <div class="codewrapper">
     <pre><code class="lang-csharp hljs">public static readonly int MAX_TERM_LENGTH</code></pre>
   </div>
   <h5 class="fieldValue">Field Value</h5>
   <table class="table table-bordered table-striped table-condensed">
     <thead>
       <tr>
         <th>Type</th>
         <th>Description</th>
       </tr>
     </thead>
     <tbody>
       <tr>
         <td><span class="xref">System.Int32</span></td>
         <td></td>
       </tr>
     </tbody>
   </table>
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   </span>
   <h4 id="Lucene_Net_Index_IndexWriter_SOURCE" data-uid="Lucene.Net.Index.IndexWriter.SOURCE">SOURCE</h4>
   <div class="markdown level1 summary"><p>Key for the source of a segment in the <a class="xref" href="Lucene.Net.Index.SegmentInfo.html#Lucene_Net_Index_SegmentInfo_Diagnostics">Diagnostics</a>. </p>
 </div>
   <div class="markdown level1 conceptual"></div>
   <h5 class="decalaration">Declaration</h5>
   <div class="codewrapper">
     <pre><code class="lang-csharp hljs">public static readonly string SOURCE</code></pre>
   </div>
   <h5 class="fieldValue">Field Value</h5>
   <table class="table table-bordered table-striped table-condensed">
     <thead>
       <tr>
         <th>Type</th>
         <th>Description</th>
       </tr>
     </thead>
     <tbody>
       <tr>
         <td><span class="xref">System.String</span></td>
         <td></td>
       </tr>
     </tbody>
   </table>
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   </span>
   <h4 id="Lucene_Net_Index_IndexWriter_SOURCE_ADDINDEXES_READERS" data-uid="Lucene.Net.Index.IndexWriter.SOURCE_ADDINDEXES_READERS">SOURCE_ADDINDEXES_READERS</h4>
   <div class="markdown level1 summary"><p>Source of a segment which results from a call to <a class="xref" href="Lucene.Net.Index.IndexWriter.html#Lucene_Net_Index_IndexWriter_AddIndexes_Lucene_Net_Index_IndexReader___">AddIndexes(IndexReader[])</a>. </p>
 </div>
   <div class="markdown level1 conceptual"></div>
   <h5 class="decalaration">Declaration</h5>
   <div class="codewrapper">
     <pre><code class="lang-csharp hljs">public static readonly string SOURCE_ADDINDEXES_READERS</code></pre>
   </div>
   <h5 class="fieldValue">Field Value</h5>
   <table class="table table-bordered table-striped table-condensed">
     <thead>
       <tr>
         <th>Type</th>
         <th>Description</th>
       </tr>
     </thead>
     <tbody>
       <tr>
         <td><span class="xref">System.String</span></td>
         <td></td>
       </tr>
     </tbody>
   </table>
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   </span>
   <h4 id="Lucene_Net_Index_IndexWriter_SOURCE_FLUSH" data-uid="Lucene.Net.Index.IndexWriter.SOURCE_FLUSH">SOURCE_FLUSH</h4>
   <div class="markdown level1 summary"><p>Source of a segment which results from a flush. </p>
 </div>
   <div class="markdown level1 conceptual"></div>
   <h5 class="decalaration">Declaration</h5>
   <div class="codewrapper">
     <pre><code class="lang-csharp hljs">public static readonly string SOURCE_FLUSH</code></pre>
   </div>
   <h5 class="fieldValue">Field Value</h5>
   <table class="table table-bordered table-striped table-condensed">
     <thead>
       <tr>
         <th>Type</th>
         <th>Description</th>
       </tr>
     </thead>
     <tbody>
       <tr>
         <td><span class="xref">System.String</span></td>
         <td></td>
       </tr>
     </tbody>
   </table>
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   <span class="small pull-right mobile-hide">
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   </span>
   <h4 id="Lucene_Net_Index_IndexWriter_SOURCE_MERGE" data-uid="Lucene.Net.Index.IndexWriter.SOURCE_MERGE">SOURCE_MERGE</h4>
   <div class="markdown level1 summary"><p>Source of a segment which results from a merge of other segments. </p>
 </div>
   <div class="markdown level1 conceptual"></div>
   <h5 class="decalaration">Declaration</h5>
   <div class="codewrapper">
     <pre><code class="lang-csharp hljs">public static readonly string SOURCE_MERGE</code></pre>
   </div>
   <h5 class="fieldValue">Field Value</h5>
   <table class="table table-bordered table-striped table-condensed">
     <thead>
       <tr>
         <th>Type</th>
         <th>Description</th>
       </tr>
     </thead>
     <tbody>
       <tr>
         <td><span class="xref">System.String</span></td>
         <td></td>
       </tr>
     </tbody>
   </table>
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   <span class="small pull-right mobile-hide">
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   </span>
   <h4 id="Lucene_Net_Index_IndexWriter_WRITE_LOCK_NAME" data-uid="Lucene.Net.Index.IndexWriter.WRITE_LOCK_NAME">WRITE_LOCK_NAME</h4>
   <div class="markdown level1 summary"><p>Name of the write lock in the index.</p>
 </div>
   <div class="markdown level1 conceptual"></div>
   <h5 class="decalaration">Declaration</h5>
   <div class="codewrapper">
     <pre><code class="lang-csharp hljs">public static readonly string WRITE_LOCK_NAME</code></pre>
   </div>
   <h5 class="fieldValue">Field Value</h5>
   <table class="table table-bordered table-striped table-condensed">
     <thead>
       <tr>
         <th>Type</th>
         <th>Description</th>
       </tr>
     </thead>
     <tbody>
       <tr>
         <td><span class="xref">System.String</span></td>
         <td></td>
       </tr>
     </tbody>
   </table>
   <h3 id="properties">Properties
   </h3>
   <span class="small pull-right mobile-hide">
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   </span>
   <a id="Lucene_Net_Index_IndexWriter_Analyzer_" data-uid="Lucene.Net.Index.IndexWriter.Analyzer*"></a>
   <h4 id="Lucene_Net_Index_IndexWriter_Analyzer" data-uid="Lucene.Net.Index.IndexWriter.Analyzer">Analyzer</h4>
   <div class="markdown level1 summary"><p>Gets the analyzer used by this index. </p>
 </div>
   <div class="markdown level1 conceptual"></div>
   <h5 class="decalaration">Declaration</h5>
   <div class="codewrapper">
     <pre><code class="lang-csharp hljs">public virtual Analyzer Analyzer { get; }</code></pre>
   </div>
   <h5 class="propertyValue">Property Value</h5>
   <table class="table table-bordered table-striped table-condensed">
     <thead>
       <tr>
         <th>Type</th>
         <th>Description</th>
       </tr>
     </thead>
     <tbody>
       <tr>
         <td><a class="xref" href="Lucene.Net.Analysis.Analyzer.html">Analyzer</a></td>
         <td></td>
       </tr>
     </tbody>
   </table>
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   </span>
   <a id="Lucene_Net_Index_IndexWriter_CommitData_" data-uid="Lucene.Net.Index.IndexWriter.CommitData*"></a>
   <h4 id="Lucene_Net_Index_IndexWriter_CommitData" data-uid="Lucene.Net.Index.IndexWriter.CommitData">CommitData</h4>
   <div class="markdown level1 summary"><p>Returns the commit user data map that was last committed, or the one that
 was set on <a class="xref" href="Lucene.Net.Index.IndexWriter.html#Lucene_Net_Index_IndexWriter_SetCommitData_System_Collections_Generic_IDictionary_System_String_System_String__">SetCommitData(IDictionary&lt;String, String&gt;)</a>.</p>
 </div>
   <div class="markdown level1 conceptual"></div>
   <h5 class="decalaration">Declaration</h5>
   <div class="codewrapper">
     <pre><code class="lang-csharp hljs">public IDictionary&lt;string, string&gt; CommitData { get; }</code></pre>
   </div>
   <h5 class="propertyValue">Property Value</h5>
   <table class="table table-bordered table-striped table-condensed">
     <thead>
       <tr>
         <th>Type</th>
         <th>Description</th>
       </tr>
     </thead>
     <tbody>
       <tr>
         <td><span class="xref">System.Collections.Generic.IDictionary</span>&lt;<span class="xref">System.String</span>, <span class="xref">System.String</span>&gt;</td>
         <td></td>
       </tr>
     </tbody>
   </table>
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   </span>
   <a id="Lucene_Net_Index_IndexWriter_Config_" data-uid="Lucene.Net.Index.IndexWriter.Config*"></a>
   <h4 id="Lucene_Net_Index_IndexWriter_Config" data-uid="Lucene.Net.Index.IndexWriter.Config">Config</h4>
   <div class="markdown level1 summary"><p>Returns a <a class="xref" href="Lucene.Net.Index.LiveIndexWriterConfig.html">LiveIndexWriterConfig</a>, which can be used to query the <a class="xref" href="Lucene.Net.Index.IndexWriter.html">IndexWriter</a>
 current settings, as well as modify &quot;live&quot; ones.</p>
 </div>
   <div class="markdown level1 conceptual"></div>
   <h5 class="decalaration">Declaration</h5>
   <div class="codewrapper">
     <pre><code class="lang-csharp hljs">public virtual LiveIndexWriterConfig Config { get; }</code></pre>
   </div>
   <h5 class="propertyValue">Property Value</h5>
   <table class="table table-bordered table-striped table-condensed">
     <thead>
       <tr>
         <th>Type</th>
         <th>Description</th>
       </tr>
     </thead>
     <tbody>
       <tr>
         <td><a class="xref" href="Lucene.Net.Index.LiveIndexWriterConfig.html">LiveIndexWriterConfig</a></td>
         <td></td>
       </tr>
     </tbody>
   </table>
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   </span>
   <a id="Lucene_Net_Index_IndexWriter_Directory_" data-uid="Lucene.Net.Index.IndexWriter.Directory*"></a>
   <h4 id="Lucene_Net_Index_IndexWriter_Directory" data-uid="Lucene.Net.Index.IndexWriter.Directory">Directory</h4>
   <div class="markdown level1 summary"><p>Gets the <a class="xref" href="Lucene.Net.Store.Directory.html">Directory</a> used by this index. </p>
 </div>
   <div class="markdown level1 conceptual"></div>
   <h5 class="decalaration">Declaration</h5>
   <div class="codewrapper">
     <pre><code class="lang-csharp hljs">public virtual Directory Directory { get; }</code></pre>
   </div>
   <h5 class="propertyValue">Property Value</h5>
   <table class="table table-bordered table-striped table-condensed">
     <thead>
       <tr>
         <th>Type</th>
         <th>Description</th>
       </tr>
     </thead>
     <tbody>
       <tr>
         <td><a class="xref" href="Lucene.Net.Store.Directory.html">Directory</a></td>
         <td></td>
       </tr>
     </tbody>
   </table>
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   </span>
   <a id="Lucene_Net_Index_IndexWriter_IsClosed_" data-uid="Lucene.Net.Index.IndexWriter.IsClosed*"></a>
   <h4 id="Lucene_Net_Index_IndexWriter_IsClosed" data-uid="Lucene.Net.Index.IndexWriter.IsClosed">IsClosed</h4>
   <div class="markdown level1 summary"></div>
   <div class="markdown level1 conceptual"></div>
   <h5 class="decalaration">Declaration</h5>
   <div class="codewrapper">
     <pre><code class="lang-csharp hljs">public virtual bool IsClosed { get; }</code></pre>
   </div>
   <h5 class="propertyValue">Property Value</h5>
   <table class="table table-bordered table-striped table-condensed">
     <thead>
       <tr>
         <th>Type</th>
         <th>Description</th>
       </tr>
     </thead>
     <tbody>
       <tr>
         <td><span class="xref">System.Boolean</span></td>
         <td></td>
       </tr>
     </tbody>
   </table>
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   </span>
   <a id="Lucene_Net_Index_IndexWriter_KeepFullyDeletedSegments_" data-uid="Lucene.Net.Index.IndexWriter.KeepFullyDeletedSegments*"></a>
   <h4 id="Lucene_Net_Index_IndexWriter_KeepFullyDeletedSegments" data-uid="Lucene.Net.Index.IndexWriter.KeepFullyDeletedSegments">KeepFullyDeletedSegments</h4>
   <div class="markdown level1 summary"><p>Only for testing.
 <p>
 <div class="lucene-block lucene-internal">This is a Lucene.NET INTERNAL API, use at your own risk</div></div>
   <div class="markdown level1 conceptual"></div>
   <h5 class="decalaration">Declaration</h5>
   <div class="codewrapper">
     <pre><code class="lang-csharp hljs">public virtual bool KeepFullyDeletedSegments { get; set; }</code></pre>
   </div>
   <h5 class="propertyValue">Property Value</h5>
   <table class="table table-bordered table-striped table-condensed">
     <thead>
       <tr>
         <th>Type</th>
         <th>Description</th>
       </tr>
     </thead>
     <tbody>
       <tr>
         <td><span class="xref">System.Boolean</span></td>
         <td></td>
       </tr>
     </tbody>
   </table>
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   </span>
   <a id="Lucene_Net_Index_IndexWriter_MaxDoc_" data-uid="Lucene.Net.Index.IndexWriter.MaxDoc*"></a>
   <h4 id="Lucene_Net_Index_IndexWriter_MaxDoc" data-uid="Lucene.Net.Index.IndexWriter.MaxDoc">MaxDoc</h4>
   <div class="markdown level1 summary"><p>Gets total number of docs in this index, including
 docs not yet flushed (still in the RAM buffer),
 not counting deletions.</p>
 </div>
   <div class="markdown level1 conceptual"></div>
   <h5 class="decalaration">Declaration</h5>
   <div class="codewrapper">
     <pre><code class="lang-csharp hljs">public virtual int MaxDoc { get; }</code></pre>
   </div>
   <h5 class="propertyValue">Property Value</h5>
   <table class="table table-bordered table-striped table-condensed">
     <thead>
       <tr>
         <th>Type</th>
         <th>Description</th>
       </tr>
     </thead>
     <tbody>
       <tr>
         <td><span class="xref">System.Int32</span></td>
         <td></td>
       </tr>
     </tbody>
   </table>
   <h5 id="Lucene_Net_Index_IndexWriter_MaxDoc_seealso">See Also</h5>
   <div class="seealso">
       <div><a class="xref" href="Lucene.Net.Index.IndexWriter.html#Lucene_Net_Index_IndexWriter_NumDocs">NumDocs</a></div>
   </div>
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   </span>
   <a id="Lucene_Net_Index_IndexWriter_MergingSegments_" data-uid="Lucene.Net.Index.IndexWriter.MergingSegments*"></a>
   <h4 id="Lucene_Net_Index_IndexWriter_MergingSegments" data-uid="Lucene.Net.Index.IndexWriter.MergingSegments">MergingSegments</h4>
   <div class="markdown level1 summary"><p>Expert: to be used by a <a class="xref" href="Lucene.Net.Index.MergePolicy.html">MergePolicy</a> to avoid
 selecting merges for segments already being merged.
 The returned collection is not cloned, and thus is
 only safe to access if you hold <a class="xref" href="Lucene.Net.Index.IndexWriter.html">IndexWriter</a>&apos;s lock
 (which you do when <a class="xref" href="Lucene.Net.Index.IndexWriter.html">IndexWriter</a> invokes the
 <a class="xref" href="Lucene.Net.Index.MergePolicy.html">MergePolicy</a>).
 <p>
 Do not alter the returned collection!</p>
 </div>
   <div class="markdown level1 conceptual"></div>
   <h5 class="decalaration">Declaration</h5>
   <div class="codewrapper">
     <pre><code class="lang-csharp hljs">public virtual ICollection&lt;SegmentCommitInfo&gt; MergingSegments { get; }</code></pre>
   </div>
   <h5 class="propertyValue">Property Value</h5>
   <table class="table table-bordered table-striped table-condensed">
     <thead>
       <tr>
         <th>Type</th>
         <th>Description</th>
       </tr>
     </thead>
     <tbody>
       <tr>
         <td><span class="xref">System.Collections.Generic.ICollection</span>&lt;<a class="xref" href="Lucene.Net.Index.SegmentCommitInfo.html">SegmentCommitInfo</a>&gt;</td>
         <td></td>
       </tr>
     </tbody>
   </table>
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   </span>
   <a id="Lucene_Net_Index_IndexWriter_NumDocs_" data-uid="Lucene.Net.Index.IndexWriter.NumDocs*"></a>
   <h4 id="Lucene_Net_Index_IndexWriter_NumDocs" data-uid="Lucene.Net.Index.IndexWriter.NumDocs">NumDocs</h4>
   <div class="markdown level1 summary"><p>Gets total number of docs in this index, including
 docs not yet flushed (still in the RAM buffer), and
 including deletions.  <strong>NOTE:</strong> buffered deletions
 are not counted.  If you really need these to be
 counted you should call <a class="xref" href="Lucene.Net.Index.IndexWriter.html#Lucene_Net_Index_IndexWriter_Commit">Commit()</a> first.</p>
 </div>
   <div class="markdown level1 conceptual"></div>
   <h5 class="decalaration">Declaration</h5>
   <div class="codewrapper">
     <pre><code class="lang-csharp hljs">public virtual int NumDocs { get; }</code></pre>
   </div>
   <h5 class="propertyValue">Property Value</h5>
   <table class="table table-bordered table-striped table-condensed">
     <thead>
       <tr>
         <th>Type</th>
         <th>Description</th>
       </tr>
     </thead>
     <tbody>
       <tr>
         <td><span class="xref">System.Int32</span></td>
         <td></td>
       </tr>
     </tbody>
   </table>
   <h5 id="Lucene_Net_Index_IndexWriter_NumDocs_seealso">See Also</h5>
   <div class="seealso">
       <div><a class="xref" href="Lucene.Net.Index.IndexWriter.html#Lucene_Net_Index_IndexWriter_MaxDoc">MaxDoc</a></div>
   </div>
   <h3 id="methods">Methods
   </h3>
   <span class="small pull-right mobile-hide">
     <span class="divider">|</span>
     <a href="https://github.com/apache/lucenenet/new/docs/4.8.0-beta00010/websites/apidocs/apiSpec/new?filename=Lucene_Net_Index_IndexWriter_AddDocument_System_Collections_Generic_IEnumerable_Lucene_Net_Index_IIndexableField__.md&amp;value=---%0Auid%3A%20Lucene.Net.Index.IndexWriter.AddDocument(System.Collections.Generic.IEnumerable%7BLucene.Net.Index.IIndexableField%7D)%0Asummary%3A%20'*You%20can%20override%20summary%20for%20the%20API%20here%20using%20*MARKDOWN*%20syntax'%0A---%0A%0A*Please%20type%20below%20more%20information%20about%20this%20API%3A*%0A%0A">Improve this Doc</a>
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   </span>
   <a id="Lucene_Net_Index_IndexWriter_AddDocument_" data-uid="Lucene.Net.Index.IndexWriter.AddDocument*"></a>
   <h4 id="Lucene_Net_Index_IndexWriter_AddDocument_System_Collections_Generic_IEnumerable_Lucene_Net_Index_IIndexableField__" data-uid="Lucene.Net.Index.IndexWriter.AddDocument(System.Collections.Generic.IEnumerable{Lucene.Net.Index.IIndexableField})">AddDocument(IEnumerable&lt;IIndexableField&gt;)</h4>
   <div class="markdown level1 summary"><p>Adds a document to this index.</p>
 <p> Note that if an <span class="xref">System.Exception</span> is hit (for example disk full)
 then the index will be consistent, but this document
 may not have been added.  Furthermore, it&apos;s possible
 the index will have one segment in non-compound format
 even when using compound files (when a merge has
 partially succeeded).</p>

 <p>This method periodically flushes pending documents
 to the <a class="xref" href="Lucene.Net.Index.IndexWriter.html#Lucene_Net_Index_IndexWriter_Directory">Directory</a> (see <a class="xref" href="Lucene.Net.Index.IndexWriter.html">IndexWriter</a>), and
 also periodically triggers segment merges in the index
 according to the <a class="xref" href="Lucene.Net.Index.MergePolicy.html">MergePolicy</a> in use.</p>

 <p>Merges temporarily consume space in the
 directory. The amount of space required is up to 1X the
 size of all segments being merged, when no
 readers/searchers are open against the index, and up to
 2X the size of all segments being merged when
 readers/searchers are open against the index (see
 <a class="xref" href="Lucene.Net.Index.IndexWriter.html#Lucene_Net_Index_IndexWriter_ForceMerge_System_Int32_">ForceMerge(Int32)</a> for details). The sequence of
 primitive merge operations performed is governed by the
 merge policy.</p>

 <p>Note that each term in the document can be no longer
 than <a class="xref" href="Lucene.Net.Index.IndexWriter.html#Lucene_Net_Index_IndexWriter_MAX_TERM_LENGTH">MAX_TERM_LENGTH</a> in bytes, otherwise an
 <span class="xref">System.ArgumentException</span> will be thrown.</p>

 <p>Note that it&apos;s possible to create an invalid Unicode
 string in java if a UTF16 surrogate pair is malformed.
 In this case, the invalid characters are silently
 replaced with the Unicode replacement character
 U+FFFD.</p>

 <p><strong>NOTE</strong>: if this method hits an <span class="xref">System.OutOfMemoryException</span>
 you should immediately dispose the writer.  See
 <a class="xref" href="Lucene.Net.Index.IndexWriter.html">IndexWriter</a> for details.</p>
 </div>
   <div class="markdown level1 conceptual"></div>
   <h5 class="decalaration">Declaration</h5>
   <div class="codewrapper">
     <pre><code class="lang-csharp hljs">public virtual void AddDocument(IEnumerable&lt;IIndexableField&gt; doc)</code></pre>
   </div>
   <h5 class="parameters">Parameters</h5>
   <table class="table table-bordered table-striped table-condensed">
     <thead>
       <tr>
         <th>Type</th>
         <th>Name</th>
         <th>Description</th>
       </tr>
     </thead>
     <tbody>
       <tr>
         <td><span class="xref">System.Collections.Generic.IEnumerable</span>&lt;<a class="xref" href="Lucene.Net.Index.IIndexableField.html">IIndexableField</a>&gt;</td>
         <td><span class="parametername">doc</span></td>
         <td></td>
       </tr>
     </tbody>
   </table>
   <h5 class="exceptions">Exceptions</h5>
   <table class="table table-bordered table-striped table-condensed">
     <thead>
       <tr>
         <th>Type</th>
         <th>Condition</th>
       </tr>
     </thead>
     <tbody>
       <tr>
         <td><a class="xref" href="Lucene.Net.Index.CorruptIndexException.html">CorruptIndexException</a></td>
         <td><p>if the index is corrupt </p>
 </td>
       </tr>
       <tr>
         <td><span class="xref">System.IO.IOException</span></td>
         <td><p>if there is a low-level IO error </p>
 </td>
       </tr>
     </tbody>
   </table>
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   </span>
   <a id="Lucene_Net_Index_IndexWriter_AddDocument_" data-uid="Lucene.Net.Index.IndexWriter.AddDocument*"></a>
   <h4 id="Lucene_Net_Index_IndexWriter_AddDocument_System_Collections_Generic_IEnumerable_Lucene_Net_Index_IIndexableField__Lucene_Net_Analysis_Analyzer_" data-uid="Lucene.Net.Index.IndexWriter.AddDocument(System.Collections.Generic.IEnumerable{Lucene.Net.Index.IIndexableField},Lucene.Net.Analysis.Analyzer)">AddDocument(IEnumerable&lt;IIndexableField&gt;, Analyzer)</h4>
   <div class="markdown level1 summary"><p>Adds a document to this index, using the provided <code data-dev-comment-type="paramref" class="paramref">analyzer</code> instead of the
 value of <a class="xref" href="Lucene.Net.Index.IndexWriter.html#Lucene_Net_Index_IndexWriter_Analyzer">Analyzer</a>.</p>
 <p>See <a class="xref" href="Lucene.Net.Index.IndexWriter.html#Lucene_Net_Index_IndexWriter_AddDocument_System_Collections_Generic_IEnumerable_Lucene_Net_Index_IIndexableField__">AddDocument(IEnumerable&lt;IIndexableField&gt;)</a> for details on
 index and <a class="xref" href="Lucene.Net.Index.IndexWriter.html">IndexWriter</a> state after an <span class="xref">System.Exception</span>, and
 flushing/merging temporary free space requirements.</p>

 <p><strong>NOTE</strong>: if this method hits an <span class="xref">System.OutOfMemoryException</span>
 you should immediately dispose the writer.  See
 <a class="xref" href="Lucene.Net.Index.IndexWriter.html">IndexWriter</a> for details.</p>
 </div>
   <div class="markdown level1 conceptual"></div>
   <h5 class="decalaration">Declaration</h5>
   <div class="codewrapper">
     <pre><code class="lang-csharp hljs">public virtual void AddDocument(IEnumerable&lt;IIndexableField&gt; doc, Analyzer analyzer)</code></pre>
   </div>
   <h5 class="parameters">Parameters</h5>
   <table class="table table-bordered table-striped table-condensed">
     <thead>
       <tr>
         <th>Type</th>
         <th>Name</th>
         <th>Description</th>
       </tr>
     </thead>
     <tbody>
       <tr>
         <td><span class="xref">System.Collections.Generic.IEnumerable</span>&lt;<a class="xref" href="Lucene.Net.Index.IIndexableField.html">IIndexableField</a>&gt;</td>
         <td><span class="parametername">doc</span></td>
         <td></td>
       </tr>
       <tr>
         <td><a class="xref" href="Lucene.Net.Analysis.Analyzer.html">Analyzer</a></td>
         <td><span class="parametername">analyzer</span></td>
         <td></td>
       </tr>
     </tbody>
   </table>
   <h5 class="exceptions">Exceptions</h5>
   <table class="table table-bordered table-striped table-condensed">
     <thead>
       <tr>
         <th>Type</th>
         <th>Condition</th>
       </tr>
     </thead>
     <tbody>
       <tr>
         <td><a class="xref" href="Lucene.Net.Index.CorruptIndexException.html">CorruptIndexException</a></td>
         <td><p>if the index is corrupt </p>
 </td>
       </tr>
       <tr>
         <td><span class="xref">System.IO.IOException</span></td>
         <td><p>if there is a low-level IO error </p>
 </td>
       </tr>
     </tbody>
   </table>
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   </span>
   <a id="Lucene_Net_Index_IndexWriter_AddDocuments_" data-uid="Lucene.Net.Index.IndexWriter.AddDocuments*"></a>
   <h4 id="Lucene_Net_Index_IndexWriter_AddDocuments_System_Collections_Generic_IEnumerable_System_Collections_Generic_IEnumerable_Lucene_Net_Index_IIndexableField___" data-uid="Lucene.Net.Index.IndexWriter.AddDocuments(System.Collections.Generic.IEnumerable{System.Collections.Generic.IEnumerable{Lucene.Net.Index.IIndexableField}})">AddDocuments(IEnumerable&lt;IEnumerable&lt;IIndexableField&gt;&gt;)</h4>
   <div class="markdown level1 summary"><p>Atomically adds a block of documents with sequentially
 assigned document IDs, such that an external reader
 will see all or none of the documents.</p>
 <p><strong>WARNING</strong>: the index does not currently record
 which documents were added as a block.  Today this is
 fine, because merging will preserve a block. The order of
 documents within a segment will be preserved, even when child
 documents within a block are deleted. Most search features
 (like result grouping and block joining) require you to
 mark documents; when these documents are deleted these
 search features will not work as expected. Obviously adding
 documents to an existing block will require you the reindex
 the entire block.</p>

 <p>However it&apos;s possible that in the future Lucene may
 merge more aggressively re-order documents (for example,
 perhaps to obtain better index compression), in which case
 you may need to fully re-index your documents at that time.</p>

 <p>See <a class="xref" href="Lucene.Net.Index.IndexWriter.html#Lucene_Net_Index_IndexWriter_AddDocument_System_Collections_Generic_IEnumerable_Lucene_Net_Index_IIndexableField__">AddDocument(IEnumerable&lt;IIndexableField&gt;)</a> for details on
 index and <a class="xref" href="Lucene.Net.Index.IndexWriter.html">IndexWriter</a> state after an <span class="xref">System.Exception</span>, and
 flushing/merging temporary free space requirements.</p>

 <p><strong>NOTE</strong>: tools that do offline splitting of an index
 (for example, IndexSplitter in Lucene.Net.Misc) or
 re-sorting of documents (for example, IndexSorter in
 contrib) are not aware of these atomically added documents
 and will likely break them up.  Use such tools at your
 own risk!</p>

 <p><strong>NOTE</strong>: if this method hits an <span class="xref">System.OutOfMemoryException</span>
 you should immediately dispose the writer.  See
 <a class="xref" href="Lucene.Net.Index.IndexWriter.html">IndexWriter</a> for details.</p>

 <div class="lucene-block lucene-experimental">This is a Lucene.NET EXPERIMENTAL API, use at your own risk</div><p>
 </div>
   <div class="markdown level1 conceptual"></div>
   <h5 class="decalaration">Declaration</h5>
   <div class="codewrapper">
     <pre><code class="lang-csharp hljs">public virtual void AddDocuments(IEnumerable&lt;IEnumerable&lt;IIndexableField&gt;&gt; docs)</code></pre>
   </div>
   <h5 class="parameters">Parameters</h5>
   <table class="table table-bordered table-striped table-condensed">
     <thead>
       <tr>
         <th>Type</th>
         <th>Name</th>
         <th>Description</th>
       </tr>
     </thead>
     <tbody>
       <tr>
         <td><span class="xref">System.Collections.Generic.IEnumerable</span>&lt;<span class="xref">System.Collections.Generic.IEnumerable</span>&lt;<a class="xref" href="Lucene.Net.Index.IIndexableField.html">IIndexableField</a>&gt;&gt;</td>
         <td><span class="parametername">docs</span></td>
         <td></td>
       </tr>
     </tbody>
   </table>
   <h5 class="exceptions">Exceptions</h5>
   <table class="table table-bordered table-striped table-condensed">
     <thead>
       <tr>
         <th>Type</th>
         <th>Condition</th>
       </tr>
     </thead>
     <tbody>
       <tr>
         <td><a class="xref" href="Lucene.Net.Index.CorruptIndexException.html">CorruptIndexException</a></td>
         <td><p>if the index is corrupt </p>
 </td>
       </tr>
       <tr>
         <td><span class="xref">System.IO.IOException</span></td>
         <td><p>if there is a low-level IO error </p>
 </td>
       </tr>
     </tbody>
   </table>
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   </span>
   <a id="Lucene_Net_Index_IndexWriter_AddDocuments_" data-uid="Lucene.Net.Index.IndexWriter.AddDocuments*"></a>
   <h4 id="Lucene_Net_Index_IndexWriter_AddDocuments_System_Collections_Generic_IEnumerable_System_Collections_Generic_IEnumerable_Lucene_Net_Index_IIndexableField___Lucene_Net_Analysis_Analyzer_" data-uid="Lucene.Net.Index.IndexWriter.AddDocuments(System.Collections.Generic.IEnumerable{System.Collections.Generic.IEnumerable{Lucene.Net.Index.IIndexableField}},Lucene.Net.Analysis.Analyzer)">AddDocuments(IEnumerable&lt;IEnumerable&lt;IIndexableField&gt;&gt;, Analyzer)</h4>
   <div class="markdown level1 summary"><p>Atomically adds a block of documents, analyzed using the
 provided <code data-dev-comment-type="paramref" class="paramref">analyzer</code>, with sequentially assigned document
 IDs, such that an external reader will see all or none
 of the documents.
 <p>
 <div class="lucene-block lucene-experimental">This is a Lucene.NET EXPERIMENTAL API, use at your own risk</div></div>
   <div class="markdown level1 conceptual"></div>
   <h5 class="decalaration">Declaration</h5>
   <div class="codewrapper">
     <pre><code class="lang-csharp hljs">public virtual void AddDocuments(IEnumerable&lt;IEnumerable&lt;IIndexableField&gt;&gt; docs, Analyzer analyzer)</code></pre>
   </div>
   <h5 class="parameters">Parameters</h5>
   <table class="table table-bordered table-striped table-condensed">
     <thead>
       <tr>
         <th>Type</th>
         <th>Name</th>
         <th>Description</th>
       </tr>
     </thead>
     <tbody>
       <tr>
         <td><span class="xref">System.Collections.Generic.IEnumerable</span>&lt;<span class="xref">System.Collections.Generic.IEnumerable</span>&lt;<a class="xref" href="Lucene.Net.Index.IIndexableField.html">IIndexableField</a>&gt;&gt;</td>
         <td><span class="parametername">docs</span></td>
         <td></td>
       </tr>
       <tr>
         <td><a class="xref" href="Lucene.Net.Analysis.Analyzer.html">Analyzer</a></td>
         <td><span class="parametername">analyzer</span></td>
         <td></td>
       </tr>
     </tbody>
   </table>
   <h5 class="exceptions">Exceptions</h5>
   <table class="table table-bordered table-striped table-condensed">
     <thead>
       <tr>
         <th>Type</th>
         <th>Condition</th>
       </tr>
     </thead>
     <tbody>
       <tr>
         <td><a class="xref" href="Lucene.Net.Index.CorruptIndexException.html">CorruptIndexException</a></td>
         <td><p>if the index is corrupt </p>
 </td>
       </tr>
       <tr>
         <td><span class="xref">System.IO.IOException</span></td>
         <td><p>if there is a low-level IO error </p>
 </td>
       </tr>
     </tbody>
   </table>
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   </span>
   <a id="Lucene_Net_Index_IndexWriter_AddIndexes_" data-uid="Lucene.Net.Index.IndexWriter.AddIndexes*"></a>
   <h4 id="Lucene_Net_Index_IndexWriter_AddIndexes_Lucene_Net_Index_IndexReader___" data-uid="Lucene.Net.Index.IndexWriter.AddIndexes(Lucene.Net.Index.IndexReader[])">AddIndexes(IndexReader[])</h4>
   <div class="markdown level1 summary"><p>Merges the provided indexes into this index.</p>
 <p><p>
 The provided <a class="xref" href="Lucene.Net.Index.IndexReader.html">IndexReader</a>s are not closed.</p>
 <p><p>
 See <a class="xref" href="Lucene.Net.Index.IndexWriter.html#Lucene_Net_Index_IndexWriter_AddIndexes_Lucene_Net_Index_IndexReader___">AddIndexes(IndexReader[])</a> for details on transactional semantics, temporary
 free space required in the <a class="xref" href="Lucene.Net.Store.Directory.html">Directory</a>, and non-CFS segments on an <span class="xref">System.Exception</span>.</p>
 <p><p>
 <strong>NOTE</strong>: if this method hits an <span class="xref">System.OutOfMemoryException</span> you should immediately
 dispose the writer. See <a class="xref" href="Lucene.Net.Index.IndexWriter.html">IndexWriter</a> for details.</p>
 <p><p>
 <strong>NOTE:</strong> empty segments are dropped by this method and not added to this
 index.</p>
 <p><p>
 <strong>NOTE:</strong> this method merges all given <a class="xref" href="Lucene.Net.Index.IndexReader.html">IndexReader</a>s in one
 merge. If you intend to merge a large number of readers, it may be better
 to call this method multiple times, each time with a small set of readers.
 In principle, if you use a merge policy with a <code>mergeFactor</code> or
 <code>maxMergeAtOnce</code> parameter, you should pass that many readers in one
 call. Also, if the given readers are <a class="xref" href="Lucene.Net.Index.DirectoryReader.html">DirectoryReader</a>s, they can be
 opened with <code>termIndexInterval=-1</code> to save RAM, since during merge
 the in-memory structure is not used. See
 <a class="xref" href="Lucene.Net.Index.DirectoryReader.html#Lucene_Net_Index_DirectoryReader_Open_Lucene_Net_Store_Directory_System_Int32_">Open(Directory, Int32)</a>.</p>
 <p><p>
 <strong>NOTE</strong>: if you call <a class="xref" href="Lucene.Net.Index.IndexWriter.html#Lucene_Net_Index_IndexWriter_Dispose_System_Boolean_">Dispose(Boolean)</a> with <code>false</code>, which
 aborts all running merges, then any thread still running this method might
 hit a <a class="xref" href="Lucene.Net.Index.MergePolicy.MergeAbortedException.html">MergePolicy.MergeAbortedException</a>.</p>
 </div>
   <div class="markdown level1 conceptual"></div>
   <h5 class="decalaration">Declaration</h5>
   <div class="codewrapper">
     <pre><code class="lang-csharp hljs">public virtual void AddIndexes(params IndexReader[] readers)</code></pre>
   </div>
   <h5 class="parameters">Parameters</h5>
   <table class="table table-bordered table-striped table-condensed">
     <thead>
       <tr>
         <th>Type</th>
         <th>Name</th>
         <th>Description</th>
       </tr>
     </thead>
     <tbody>
       <tr>
         <td><a class="xref" href="Lucene.Net.Index.IndexReader.html">IndexReader</a>[]</td>
         <td><span class="parametername">readers</span></td>
         <td></td>
       </tr>
     </tbody>
   </table>
   <h5 class="exceptions">Exceptions</h5>
   <table class="table table-bordered table-striped table-condensed">
     <thead>
       <tr>
         <th>Type</th>
         <th>Condition</th>
       </tr>
     </thead>
     <tbody>
       <tr>
         <td><a class="xref" href="Lucene.Net.Index.CorruptIndexException.html">CorruptIndexException</a></td>
         <td><p>if the index is corrupt </p>
 </td>
       </tr>
       <tr>
         <td><span class="xref">System.IO.IOException</span></td>
         <td><p>if there is a low-level IO error </p>
 </td>
       </tr>
     </tbody>
   </table>
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   </span>
   <a id="Lucene_Net_Index_IndexWriter_AddIndexes_" data-uid="Lucene.Net.Index.IndexWriter.AddIndexes*"></a>
   <h4 id="Lucene_Net_Index_IndexWriter_AddIndexes_Lucene_Net_Store_Directory___" data-uid="Lucene.Net.Index.IndexWriter.AddIndexes(Lucene.Net.Store.Directory[])">AddIndexes(Directory[])</h4>
   <div class="markdown level1 summary"><p>Adds all segments from an array of indexes into this index.</p>
 <p><p>This may be used to parallelize batch indexing. A large document
 collection can be broken into sub-collections. Each sub-collection can be
 indexed in parallel, on a different thread, process or machine. The
 complete index can then be created by merging sub-collection indexes
 with this method.</p>
 <p><p>
 <strong>NOTE:</strong> this method acquires the write lock in
 each directory, to ensure that no <a class="xref" href="Lucene.Net.Index.IndexWriter.html">IndexWriter</a>
 is currently open or tries to open while this is
 running.</p>
 <p><p>This method is transactional in how <span class="xref">System.Exception</span>s are
 handled: it does not commit a new segments_N file until
 all indexes are added.  this means if an <span class="xref">System.Exception</span>
 occurs (for example disk full), then either no indexes
 will have been added or they all will have been.</p>
 <p><p>Note that this requires temporary free space in the
 <a class="xref" href="Lucene.Net.Store.Directory.html">Directory</a> up to 2X the sum of all input indexes
 (including the starting index). If readers/searchers
 are open against the starting index, then temporary
 free space required will be higher by the size of the
 starting index (see <a class="xref" href="Lucene.Net.Index.IndexWriter.html#Lucene_Net_Index_IndexWriter_ForceMerge_System_Int32_">ForceMerge(Int32)</a> for details).</p>
 <p><p>
 <strong>NOTE:</strong> this method only copies the segments of the incoming indexes
 and does not merge them. Therefore deleted documents are not removed and
 the new segments are not merged with the existing ones.</p>
 <p><p>This requires this index not be among those to be added.</p>
 <p><p>
 <strong>NOTE</strong>: if this method hits an <span class="xref">System.OutOfMemoryException</span>
 you should immediately dispose the writer. See
 <a class="xref" href="Lucene.Net.Index.IndexWriter.html">IndexWriter</a> for details.</p>
 </div>
   <div class="markdown level1 conceptual"></div>
   <h5 class="decalaration">Declaration</h5>
   <div class="codewrapper">
     <pre><code class="lang-csharp hljs">public virtual void AddIndexes(params Directory[] dirs)</code></pre>
   </div>
   <h5 class="parameters">Parameters</h5>
   <table class="table table-bordered table-striped table-condensed">
     <thead>
       <tr>
         <th>Type</th>
         <th>Name</th>
         <th>Description</th>
       </tr>
     </thead>
     <tbody>
       <tr>
         <td><a class="xref" href="Lucene.Net.Store.Directory.html">Directory</a>[]</td>
         <td><span class="parametername">dirs</span></td>
         <td></td>
       </tr>
     </tbody>
   </table>
   <h5 class="exceptions">Exceptions</h5>
   <table class="table table-bordered table-striped table-condensed">
     <thead>
       <tr>
         <th>Type</th>
         <th>Condition</th>
       </tr>
     </thead>
     <tbody>
       <tr>
         <td><a class="xref" href="Lucene.Net.Index.CorruptIndexException.html">CorruptIndexException</a></td>
         <td><p>if the index is corrupt </p>
 </td>
       </tr>
       <tr>
         <td><span class="xref">System.IO.IOException</span></td>
         <td><p>if there is a low-level IO error </p>
 </td>
       </tr>
       <tr>
         <td><a class="xref" href="Lucene.Net.Store.LockObtainFailedException.html">LockObtainFailedException</a></td>
         <td><p>if we were unable to
  acquire the write lock in at least one directory </p>
 </td>
       </tr>
     </tbody>
   </table>
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   </span>
   <a id="Lucene_Net_Index_IndexWriter_Commit_" data-uid="Lucene.Net.Index.IndexWriter.Commit*"></a>
   <h4 id="Lucene_Net_Index_IndexWriter_Commit" data-uid="Lucene.Net.Index.IndexWriter.Commit">Commit()</h4>
   <div class="markdown level1 summary"><p>Commits all pending changes (added &amp; deleted
 documents, segment merges, added
 indexes, etc.) to the index, and syncs all referenced
 index files, such that a reader will see the changes
 and the index updates will survive an OS or machine
 crash or power loss.  Note that this does not wait for
 any running background merges to finish.  This may be a
 costly operation, so you should test the cost in your
 application and do it only when really necessary.</p>

 <p> Note that this operation calls <a class="xref" href="Lucene.Net.Store.Directory.html#Lucene_Net_Store_Directory_Sync_System_Collections_Generic_ICollection_System_String__">Sync(ICollection&lt;String&gt;)</a> on
 the index files.  That call should not return until the
 file contents &amp; metadata are on stable storage.  For
 <a class="xref" href="Lucene.Net.Store.FSDirectory.html">FSDirectory</a>, this calls the OS&apos;s fsync.  But, beware:
 some hardware devices may in fact cache writes even
 during fsync, and return before the bits are actually
 on stable storage, to give the appearance of faster
 performance.  If you have such a device, and it does
 not have a battery backup (for example) then on power
 loss it may still lose data.  Lucene cannot guarantee
 consistency on such devices.  </p>

 <p><strong>NOTE</strong>: if this method hits an <span class="xref">System.OutOfMemoryException</span>
 you should immediately dispose the writer.  See
 <a class="xref" href="Lucene.Net.Index.IndexWriter.html">IndexWriter</a> for details.</p>
 </div>
   <div class="markdown level1 conceptual"></div>
   <h5 class="decalaration">Declaration</h5>
   <div class="codewrapper">
     <pre><code class="lang-csharp hljs">public void Commit()</code></pre>
   </div>
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   </span>
   <a id="Lucene_Net_Index_IndexWriter_DeleteAll_" data-uid="Lucene.Net.Index.IndexWriter.DeleteAll*"></a>
   <h4 id="Lucene_Net_Index_IndexWriter_DeleteAll" data-uid="Lucene.Net.Index.IndexWriter.DeleteAll">DeleteAll()</h4>
   <div class="markdown level1 summary"><p>Delete all documents in the index.</p>
 <p>This method will drop all buffered documents and will
    remove all segments from the index. This change will not be
    visible until a <a class="xref" href="Lucene.Net.Index.IndexWriter.html#Lucene_Net_Index_IndexWriter_Commit">Commit()</a> has been called. This method
    can be rolled back using <a class="xref" href="Lucene.Net.Index.IndexWriter.html#Lucene_Net_Index_IndexWriter_Rollback">Rollback()</a>.</p>

 <p>NOTE: this method is much faster than using <code>DeleteDocuments(new MatchAllDocsQuery())</code>.
    Yet, this method also has different semantics compared to <a class="xref" href="Lucene.Net.Index.IndexWriter.html#Lucene_Net_Index_IndexWriter_DeleteDocuments_Lucene_Net_Search_Query_">DeleteDocuments(Query)</a>
    / <a class="xref" href="Lucene.Net.Index.IndexWriter.html#Lucene_Net_Index_IndexWriter_DeleteDocuments_Lucene_Net_Search_Query___">DeleteDocuments(Query[])</a> since internal data-structures are cleared as well
    as all segment information is forcefully dropped anti-viral semantics like omitting norms
    are reset or doc value types are cleared. Essentially a call to <a class="xref" href="Lucene.Net.Index.IndexWriter.html#Lucene_Net_Index_IndexWriter_DeleteAll">DeleteAll()</a> is equivalent
    to creating a new <a class="xref" href="Lucene.Net.Index.IndexWriter.html">IndexWriter</a> with <a class="xref" href="Lucene.Net.Index.OpenMode.html#Lucene_Net_Index_OpenMode_CREATE">CREATE</a> which a delete query only marks
    documents as deleted.</p>

 <p>NOTE: this method will forcefully abort all merges
    in progress.  If other threads are running
 <a class="xref" href="Lucene.Net.Index.IndexWriter.html#Lucene_Net_Index_IndexWriter_ForceMerge_System_Int32_">ForceMerge(Int32)</a>, <a class="xref" href="Lucene.Net.Index.IndexWriter.html#Lucene_Net_Index_IndexWriter_AddIndexes_Lucene_Net_Index_IndexReader___">AddIndexes(IndexReader[])</a> or
 <a class="xref" href="Lucene.Net.Index.IndexWriter.html#Lucene_Net_Index_IndexWriter_ForceMergeDeletes">ForceMergeDeletes()</a> methods, they may receive
 <a class="xref" href="Lucene.Net.Index.MergePolicy.MergeAbortedException.html">MergePolicy.MergeAbortedException</a>s.</p>
 </div>
   <div class="markdown level1 conceptual"></div>
   <h5 class="decalaration">Declaration</h5>
   <div class="codewrapper">
     <pre><code class="lang-csharp hljs">public virtual void DeleteAll()</code></pre>
   </div>
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   </span>
   <a id="Lucene_Net_Index_IndexWriter_DeleteDocuments_" data-uid="Lucene.Net.Index.IndexWriter.DeleteDocuments*"></a>
   <h4 id="Lucene_Net_Index_IndexWriter_DeleteDocuments_Lucene_Net_Index_Term_" data-uid="Lucene.Net.Index.IndexWriter.DeleteDocuments(Lucene.Net.Index.Term)">DeleteDocuments(Term)</h4>
   <div class="markdown level1 summary"><p>Deletes the document(s) containing <code data-dev-comment-type="paramref" class="paramref">term</code>.</p>
 <p><strong>NOTE</strong>: if this method hits an <span class="xref">System.OutOfMemoryException</span>
 you should immediately dispose the writer.  See
 <a class="xref" href="Lucene.Net.Index.IndexWriter.html">IndexWriter</a> for details.</p>
 </div>
   <div class="markdown level1 conceptual"></div>
   <h5 class="decalaration">Declaration</h5>
   <div class="codewrapper">
     <pre><code class="lang-csharp hljs">public virtual void DeleteDocuments(Term term)</code></pre>
   </div>
   <h5 class="parameters">Parameters</h5>
   <table class="table table-bordered table-striped table-condensed">
     <thead>
       <tr>
         <th>Type</th>
         <th>Name</th>
         <th>Description</th>
       </tr>
     </thead>
     <tbody>
       <tr>
         <td><a class="xref" href="Lucene.Net.Index.Term.html">Term</a></td>
         <td><span class="parametername">term</span></td>
         <td><p>the term to identify the documents to be deleted </p>
 </td>
       </tr>
     </tbody>
   </table>
   <h5 class="exceptions">Exceptions</h5>
   <table class="table table-bordered table-striped table-condensed">
     <thead>
       <tr>
         <th>Type</th>
         <th>Condition</th>
       </tr>
     </thead>
     <tbody>
       <tr>
         <td><a class="xref" href="Lucene.Net.Index.CorruptIndexException.html">CorruptIndexException</a></td>
         <td><p>if the index is corrupt </p>
 </td>
       </tr>
       <tr>
         <td><span class="xref">System.IO.IOException</span></td>
         <td><p>if there is a low-level IO error </p>
 </td>
       </tr>
     </tbody>
   </table>
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   </span>
   <a id="Lucene_Net_Index_IndexWriter_DeleteDocuments_" data-uid="Lucene.Net.Index.IndexWriter.DeleteDocuments*"></a>
   <h4 id="Lucene_Net_Index_IndexWriter_DeleteDocuments_Lucene_Net_Index_Term___" data-uid="Lucene.Net.Index.IndexWriter.DeleteDocuments(Lucene.Net.Index.Term[])">DeleteDocuments(Term[])</h4>
   <div class="markdown level1 summary"><p>Deletes the document(s) containing any of the
 terms. All given deletes are applied and flushed atomically
 at the same time.</p>
 <p><strong>NOTE</strong>: if this method hits an <span class="xref">System.OutOfMemoryException</span>
 you should immediately dispose the writer.  See
 <a class="xref" href="Lucene.Net.Index.IndexWriter.html">IndexWriter</a> for details.</p>
 </div>
   <div class="markdown level1 conceptual"></div>
   <h5 class="decalaration">Declaration</h5>
   <div class="codewrapper">
     <pre><code class="lang-csharp hljs">public virtual void DeleteDocuments(params Term[] terms)</code></pre>
   </div>
   <h5 class="parameters">Parameters</h5>
   <table class="table table-bordered table-striped table-condensed">
     <thead>
       <tr>
         <th>Type</th>
         <th>Name</th>
         <th>Description</th>
       </tr>
     </thead>
     <tbody>
       <tr>
         <td><a class="xref" href="Lucene.Net.Index.Term.html">Term</a>[]</td>
         <td><span class="parametername">terms</span></td>
         <td><p>array of terms to identify the documents
 to be deleted </p>
 </td>
       </tr>
     </tbody>
   </table>
   <h5 class="exceptions">Exceptions</h5>
   <table class="table table-bordered table-striped table-condensed">
     <thead>
       <tr>
         <th>Type</th>
         <th>Condition</th>
       </tr>
     </thead>
     <tbody>
       <tr>
         <td><a class="xref" href="Lucene.Net.Index.CorruptIndexException.html">CorruptIndexException</a></td>
         <td><p>if the index is corrupt </p>
 </td>
       </tr>
       <tr>
         <td><span class="xref">System.IO.IOException</span></td>
         <td><p>if there is a low-level IO error </p>
 </td>
       </tr>
     </tbody>
   </table>
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   </span>
   <a id="Lucene_Net_Index_IndexWriter_DeleteDocuments_" data-uid="Lucene.Net.Index.IndexWriter.DeleteDocuments*"></a>
   <h4 id="Lucene_Net_Index_IndexWriter_DeleteDocuments_Lucene_Net_Search_Query_" data-uid="Lucene.Net.Index.IndexWriter.DeleteDocuments(Lucene.Net.Search.Query)">DeleteDocuments(Query)</h4>
   <div class="markdown level1 summary"><p>Deletes the document(s) matching the provided query.</p>
 <p><strong>NOTE</strong>: if this method hits an <span class="xref">System.OutOfMemoryException</span>
 you should immediately dispose the writer.  See
 <a class="xref" href="Lucene.Net.Index.IndexWriter.html">IndexWriter</a> for details.</p>
 </div>
   <div class="markdown level1 conceptual"></div>
   <h5 class="decalaration">Declaration</h5>
   <div class="codewrapper">
     <pre><code class="lang-csharp hljs">public virtual void DeleteDocuments(Query query)</code></pre>
   </div>
   <h5 class="parameters">Parameters</h5>
   <table class="table table-bordered table-striped table-condensed">
     <thead>
       <tr>
         <th>Type</th>
         <th>Name</th>
         <th>Description</th>
       </tr>
     </thead>
     <tbody>
       <tr>
         <td><a class="xref" href="Lucene.Net.Search.Query.html">Query</a></td>
         <td><span class="parametername">query</span></td>
         <td><p>the query to identify the documents to be deleted </p>
 </td>
       </tr>
     </tbody>
   </table>
   <h5 class="exceptions">Exceptions</h5>
   <table class="table table-bordered table-striped table-condensed">
     <thead>
       <tr>
         <th>Type</th>
         <th>Condition</th>
       </tr>
     </thead>
     <tbody>
       <tr>
         <td><a class="xref" href="Lucene.Net.Index.CorruptIndexException.html">CorruptIndexException</a></td>
         <td><p>if the index is corrupt </p>
 </td>
       </tr>
       <tr>
         <td><span class="xref">System.IO.IOException</span></td>
         <td><p>if there is a low-level IO error </p>
 </td>
       </tr>
     </tbody>
   </table>
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   </span>
   <a id="Lucene_Net_Index_IndexWriter_DeleteDocuments_" data-uid="Lucene.Net.Index.IndexWriter.DeleteDocuments*"></a>
   <h4 id="Lucene_Net_Index_IndexWriter_DeleteDocuments_Lucene_Net_Search_Query___" data-uid="Lucene.Net.Index.IndexWriter.DeleteDocuments(Lucene.Net.Search.Query[])">DeleteDocuments(Query[])</h4>
   <div class="markdown level1 summary"><p>Deletes the document(s) matching any of the provided queries.
 All given deletes are applied and flushed atomically at the same time.</p>
 <p><strong>NOTE</strong>: if this method hits an <span class="xref">System.OutOfMemoryException</span>
 you should immediately dispose the writer.  See
 <a class="xref" href="Lucene.Net.Index.IndexWriter.html">IndexWriter</a> for details.</p>
 </div>
   <div class="markdown level1 conceptual"></div>
   <h5 class="decalaration">Declaration</h5>
   <div class="codewrapper">
     <pre><code class="lang-csharp hljs">public virtual void DeleteDocuments(params Query[] queries)</code></pre>
   </div>
   <h5 class="parameters">Parameters</h5>
   <table class="table table-bordered table-striped table-condensed">
     <thead>
       <tr>
         <th>Type</th>
         <th>Name</th>
         <th>Description</th>
       </tr>
     </thead>
     <tbody>
       <tr>
         <td><a class="xref" href="Lucene.Net.Search.Query.html">Query</a>[]</td>
         <td><span class="parametername">queries</span></td>
         <td><p>array of queries to identify the documents
 to be deleted </p>
 </td>
       </tr>
     </tbody>
   </table>
   <h5 class="exceptions">Exceptions</h5>
   <table class="table table-bordered table-striped table-condensed">
     <thead>
       <tr>
         <th>Type</th>
         <th>Condition</th>
       </tr>
     </thead>
     <tbody>
       <tr>
         <td><a class="xref" href="Lucene.Net.Index.CorruptIndexException.html">CorruptIndexException</a></td>
         <td><p>if the index is corrupt </p>
 </td>
       </tr>
       <tr>
         <td><span class="xref">System.IO.IOException</span></td>
         <td><p>if there is a low-level IO error </p>
 </td>
       </tr>
     </tbody>
   </table>
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   <a id="Lucene_Net_Index_IndexWriter_DeleteUnusedFiles_" data-uid="Lucene.Net.Index.IndexWriter.DeleteUnusedFiles*"></a>
   <h4 id="Lucene_Net_Index_IndexWriter_DeleteUnusedFiles" data-uid="Lucene.Net.Index.IndexWriter.DeleteUnusedFiles">DeleteUnusedFiles()</h4>
   <div class="markdown level1 summary"><p>Expert: remove any index files that are no longer
 used.</p>
 <p> <a class="xref" href="Lucene.Net.Index.IndexWriter.html">IndexWriter</a> normally deletes unused files itself,
 during indexing.  However, on Windows, which disallows
 deletion of open files, if there is a reader open on
 the index then those files cannot be deleted.  This is
 fine, because <a class="xref" href="Lucene.Net.Index.IndexWriter.html">IndexWriter</a> will periodically retry
 the deletion.</p>

 <p> However, <a class="xref" href="Lucene.Net.Index.IndexWriter.html">IndexWriter</a> doesn&apos;t try that often: only
 on open, close, flushing a new segment, and finishing
 a merge.  If you don&apos;t do any of these actions with your
 <a class="xref" href="Lucene.Net.Index.IndexWriter.html">IndexWriter</a>, you&apos;ll see the unused files linger.  If
 that&apos;s a problem, call this method to delete them
 (once you&apos;ve closed the open readers that were
 preventing their deletion).</p>

 <p> In addition, you can call this method to delete
 unreferenced index commits. this might be useful if you
 are using an <a class="xref" href="Lucene.Net.Index.IndexDeletionPolicy.html">IndexDeletionPolicy</a> which holds
 onto index commits until some criteria are met, but those
 commits are no longer needed. Otherwise, those commits will
 be deleted the next time <a class="xref" href="Lucene.Net.Index.IndexWriter.html#Lucene_Net_Index_IndexWriter_Commit">Commit()</a> is called.</p>
 </div>
   <div class="markdown level1 conceptual"></div>
   <h5 class="decalaration">Declaration</h5>
   <div class="codewrapper">
     <pre><code class="lang-csharp hljs">public virtual void DeleteUnusedFiles()</code></pre>
   </div>
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   </span>
   <a id="Lucene_Net_Index_IndexWriter_Dispose_" data-uid="Lucene.Net.Index.IndexWriter.Dispose*"></a>
   <h4 id="Lucene_Net_Index_IndexWriter_Dispose" data-uid="Lucene.Net.Index.IndexWriter.Dispose">Dispose()</h4>
   <div class="markdown level1 summary"><p>Commits all changes to an index, waits for pending merges
 to complete, and closes all associated files.
 <p>
 This is a &quot;slow graceful shutdown&quot; which may take a long time
 especially if a big merge is pending: If you only want to close
 resources use <a class="xref" href="Lucene.Net.Index.IndexWriter.html#Lucene_Net_Index_IndexWriter_Rollback">Rollback()</a>. If you only want to commit
 pending changes and close resources see <a class="xref" href="Lucene.Net.Index.IndexWriter.html#Lucene_Net_Index_IndexWriter_Dispose_System_Boolean_">Dispose(Boolean)</a>.
 <p>
 Note that this may be a costly
 operation, so, try to re-use a single writer instead of
 closing and opening a new one.  See <a class="xref" href="Lucene.Net.Index.IndexWriter.html#Lucene_Net_Index_IndexWriter_Commit">Commit()</a> for
 caveats about write caching done by some IO devices.</p>
 <p> If an <span class="xref">System.Exception</span> is hit during close, eg due to disk
 full or some other reason, then both the on-disk index
 and the internal state of the <a class="xref" href="Lucene.Net.Index.IndexWriter.html">IndexWriter</a> instance will
 be consistent.  However, the close will not be complete
 even though part of it (flushing buffered documents)
 may have succeeded, so the write lock will still be
 held.</p>

 <p> If you can correct the underlying cause (eg free up
 some disk space) then you can call <a class="xref" href="Lucene.Net.Index.IndexWriter.html#Lucene_Net_Index_IndexWriter_Dispose">Dispose()</a> again.
 Failing that, if you want to force the write lock to be
 released (dangerous, because you may then lose buffered
 docs in the <a class="xref" href="Lucene.Net.Index.IndexWriter.html">IndexWriter</a> instance) then you can do
 something like this:</p>

 <pre><code>try
 {
     writer.Dispose();
 }
 finally
 {
     if (IndexWriter.IsLocked(directory))
     {
         IndexWriter.Unlock(directory);
     }
 }</code></pre>

 <p>after which, you must be certain not to use the writer
 instance anymore.</p>
 <p><strong>NOTE</strong>: if this method hits an <span class="xref">System.OutOfMemoryException</span>
 you should immediately dispose the writer, again.  See
 <a class="xref" href="Lucene.Net.Index.IndexWriter.html">IndexWriter</a> for details.</p>
 </div>
   <div class="markdown level1 conceptual"></div>
   <h5 class="decalaration">Declaration</h5>
   <div class="codewrapper">
     <pre><code class="lang-csharp hljs">public void Dispose()</code></pre>
   </div>
   <h5 class="exceptions">Exceptions</h5>
   <table class="table table-bordered table-striped table-condensed">
     <thead>
       <tr>
         <th>Type</th>
         <th>Condition</th>
       </tr>
     </thead>
     <tbody>
       <tr>
         <td><span class="xref">System.IO.IOException</span></td>
         <td><p>if there is a low-level IO error </p>
 </td>
       </tr>
     </tbody>
   </table>
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   </span>
   <a id="Lucene_Net_Index_IndexWriter_Dispose_" data-uid="Lucene.Net.Index.IndexWriter.Dispose*"></a>
   <h4 id="Lucene_Net_Index_IndexWriter_Dispose_System_Boolean_" data-uid="Lucene.Net.Index.IndexWriter.Dispose(System.Boolean)">Dispose(Boolean)</h4>
   <div class="markdown level1 summary"><p>Closes the index with or without waiting for currently
 running merges to finish.  This is only meaningful when
 using a <a class="xref" href="Lucene.Net.Index.MergeScheduler.html">MergeScheduler</a> that runs merges in background
 threads.</p>
 <p><strong>NOTE</strong>: if this method hits an <span class="xref">System.OutOfMemoryException</span>
 you should immediately dispose the writer, again.  See
 <a class="xref" href="Lucene.Net.Index.IndexWriter.html">IndexWriter</a> for details.</p>

 <p><strong>NOTE</strong>: it is dangerous to always call
 <code>Dispose(false)</code>, especially when <a class="xref" href="Lucene.Net.Index.IndexWriter.html">IndexWriter</a> is not open
 for very long, because this can result in &quot;merge
 starvation&quot; whereby long merges will never have a
 chance to finish.  This will cause too many segments in
 your index over time.</p>
 </div>
   <div class="markdown level1 conceptual"></div>
   <h5 class="decalaration">Declaration</h5>
   <div class="codewrapper">
     <pre><code class="lang-csharp hljs">public virtual void Dispose(bool waitForMerges)</code></pre>
   </div>
   <h5 class="parameters">Parameters</h5>
   <table class="table table-bordered table-striped table-condensed">
     <thead>
       <tr>
         <th>Type</th>
         <th>Name</th>
         <th>Description</th>
       </tr>
     </thead>
     <tbody>
       <tr>
         <td><span class="xref">System.Boolean</span></td>
         <td><span class="parametername">waitForMerges</span></td>
         <td><p>if <code>true</code>, this call will block
 until all merges complete; else, it will ask all
 running merges to abort, wait until those merges have
 finished (which should be at most a few seconds), and
 then return. </p>
 </td>
       </tr>
     </tbody>
   </table>
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   </span>
   <a id="Lucene_Net_Index_IndexWriter_DoAfterFlush_" data-uid="Lucene.Net.Index.IndexWriter.DoAfterFlush*"></a>
   <h4 id="Lucene_Net_Index_IndexWriter_DoAfterFlush" data-uid="Lucene.Net.Index.IndexWriter.DoAfterFlush">DoAfterFlush()</h4>
   <div class="markdown level1 summary"><p>A hook for extending classes to execute operations after pending added and
 deleted documents have been flushed to the <a class="xref" href="Lucene.Net.Store.Directory.html">Directory</a> but before the change
 is committed (new segments_N file written).</p>
 </div>
   <div class="markdown level1 conceptual"></div>
   <h5 class="decalaration">Declaration</h5>
   <div class="codewrapper">
     <pre><code class="lang-csharp hljs">protected virtual void DoAfterFlush()</code></pre>
   </div>
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   <a id="Lucene_Net_Index_IndexWriter_DoBeforeFlush_" data-uid="Lucene.Net.Index.IndexWriter.DoBeforeFlush*"></a>
   <h4 id="Lucene_Net_Index_IndexWriter_DoBeforeFlush" data-uid="Lucene.Net.Index.IndexWriter.DoBeforeFlush">DoBeforeFlush()</h4>
   <div class="markdown level1 summary"><p>A hook for extending classes to execute operations before pending added and
 deleted documents are flushed to the <a class="xref" href="Lucene.Net.Store.Directory.html">Directory</a>.</p>
 </div>
   <div class="markdown level1 conceptual"></div>
   <h5 class="decalaration">Declaration</h5>
   <div class="codewrapper">
     <pre><code class="lang-csharp hljs">protected virtual void DoBeforeFlush()</code></pre>
   </div>
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   </span>
   <a id="Lucene_Net_Index_IndexWriter_EnsureOpen_" data-uid="Lucene.Net.Index.IndexWriter.EnsureOpen*"></a>
   <h4 id="Lucene_Net_Index_IndexWriter_EnsureOpen" data-uid="Lucene.Net.Index.IndexWriter.EnsureOpen">EnsureOpen()</h4>
   <div class="markdown level1 summary"><p>Used internally to throw an
 <span class="xref">System.ObjectDisposedException</span> if this <a class="xref" href="Lucene.Net.Index.IndexWriter.html">IndexWriter</a> has been
 disposed (<code>closed=true</code>) or is in the process of
 disposing (<code>closing=true</code>).
 <p>
 Calls <a class="xref" href="Lucene.Net.Index.IndexWriter.html#Lucene_Net_Index_IndexWriter_EnsureOpen_System_Boolean_">EnsureOpen(Boolean)</a>.</p>
 </div>
   <div class="markdown level1 conceptual"></div>
   <h5 class="decalaration">Declaration</h5>
   <div class="codewrapper">
     <pre><code class="lang-csharp hljs">protected void EnsureOpen()</code></pre>
   </div>
   <h5 class="exceptions">Exceptions</h5>
   <table class="table table-bordered table-striped table-condensed">
     <thead>
       <tr>
         <th>Type</th>
         <th>Condition</th>
       </tr>
     </thead>
     <tbody>
       <tr>
         <td><span class="xref">System.ObjectDisposedException</span></td>
         <td><p>if this <a class="xref" href="Lucene.Net.Index.IndexWriter.html">IndexWriter</a> is disposed </p>
 </td>
       </tr>
     </tbody>
   </table>
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   </span>
   <a id="Lucene_Net_Index_IndexWriter_EnsureOpen_" data-uid="Lucene.Net.Index.IndexWriter.EnsureOpen*"></a>
   <h4 id="Lucene_Net_Index_IndexWriter_EnsureOpen_System_Boolean_" data-uid="Lucene.Net.Index.IndexWriter.EnsureOpen(System.Boolean)">EnsureOpen(Boolean)</h4>
   <div class="markdown level1 summary"><p>Used internally to throw an <span class="xref">System.ObjectDisposedException</span> if this
 <a class="xref" href="Lucene.Net.Index.IndexWriter.html">IndexWriter</a> has been disposed or is in the process of diposing.</p>
 </div>
   <div class="markdown level1 conceptual"></div>
   <h5 class="decalaration">Declaration</h5>
   <div class="codewrapper">
     <pre><code class="lang-csharp hljs">protected void EnsureOpen(bool failIfDisposing)</code></pre>
   </div>
   <h5 class="parameters">Parameters</h5>
   <table class="table table-bordered table-striped table-condensed">
     <thead>
       <tr>
         <th>Type</th>
         <th>Name</th>
         <th>Description</th>
       </tr>
     </thead>
     <tbody>
       <tr>
         <td><span class="xref">System.Boolean</span></td>
         <td><span class="parametername">failIfDisposing</span></td>
         <td><p>if <code>true</code>, also fail when <a class="xref" href="Lucene.Net.Index.IndexWriter.html">IndexWriter</a> is in the process of
 disposing (<code>closing=true</code>) but not yet done disposing (
 <code>closed=false</code>) </p>
 </td>
       </tr>
     </tbody>
   </table>
   <h5 class="exceptions">Exceptions</h5>
   <table class="table table-bordered table-striped table-condensed">
     <thead>
       <tr>
         <th>Type</th>
         <th>Condition</th>
       </tr>
     </thead>
     <tbody>
       <tr>
         <td><span class="xref">System.ObjectDisposedException</span></td>
         <td><p>if this IndexWriter is closed or in the process of closing </p>
 </td>
       </tr>
     </tbody>
   </table>
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   <a id="Lucene_Net_Index_IndexWriter_Flush_" data-uid="Lucene.Net.Index.IndexWriter.Flush*"></a>
   <h4 id="Lucene_Net_Index_IndexWriter_Flush_System_Boolean_System_Boolean_" data-uid="Lucene.Net.Index.IndexWriter.Flush(System.Boolean,System.Boolean)">Flush(Boolean, Boolean)</h4>
   <div class="markdown level1 summary"><p>Flush all in-memory buffered updates (adds and deletes)
 to the <a class="xref" href="Lucene.Net.Store.Directory.html">Directory</a>. </p>
 </div>
   <div class="markdown level1 conceptual"></div>
   <h5 class="decalaration">Declaration</h5>
   <div class="codewrapper">
     <pre><code class="lang-csharp hljs">public void Flush(bool triggerMerge, bool applyAllDeletes)</code></pre>
   </div>
   <h5 class="parameters">Parameters</h5>
   <table class="table table-bordered table-striped table-condensed">
     <thead>
       <tr>
         <th>Type</th>
         <th>Name</th>
         <th>Description</th>
       </tr>
     </thead>
     <tbody>
       <tr>
         <td><span class="xref">System.Boolean</span></td>
         <td><span class="parametername">triggerMerge</span></td>
         <td><p>if <code>true</code>, we may merge segments (if
 deletes or docs were flushed) if necessary </p>
 </td>
       </tr>
       <tr>
         <td><span class="xref">System.Boolean</span></td>
         <td><span class="parametername">applyAllDeletes</span></td>
         <td><p>whether pending deletes should also </p>
 </td>
       </tr>
     </tbody>
   </table>
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   </span>
   <a id="Lucene_Net_Index_IndexWriter_ForceMerge_" data-uid="Lucene.Net.Index.IndexWriter.ForceMerge*"></a>
   <h4 id="Lucene_Net_Index_IndexWriter_ForceMerge_System_Int32_" data-uid="Lucene.Net.Index.IndexWriter.ForceMerge(System.Int32)">ForceMerge(Int32)</h4>
   <div class="markdown level1 summary"><p>Forces merge policy to merge segments until there are &lt;=
 <code data-dev-comment-type="paramref" class="paramref">maxNumSegments</code>.  The actual merges to be
 executed are determined by the <a class="xref" href="Lucene.Net.Index.MergePolicy.html">MergePolicy</a>.</p>
 <p>This is a horribly costly operation, especially when
 you pass a small <code data-dev-comment-type="paramref" class="paramref">maxNumSegments</code>; usually you
 should only call this if the index is static (will no
 longer be changed).</p>

 <p>Note that this requires up to 2X the index size free
 space in your Directory (3X if you&apos;re using compound
 file format).  For example, if your index size is 10 MB
 then you need up to 20 MB free for this to complete (30
 MB if you&apos;re using compound file format).  Also,
 it&apos;s best to call <a class="xref" href="Lucene.Net.Index.IndexWriter.html#Lucene_Net_Index_IndexWriter_Commit">Commit()</a> afterwards,
 to allow <a class="xref" href="Lucene.Net.Index.IndexWriter.html">IndexWriter</a> to free up disk space.</p>

 <p>If some but not all readers re-open while merging
 is underway, this will cause &gt; 2X temporary
 space to be consumed as those new readers will then
 hold open the temporary segments at that time.  It is
 best not to re-open readers while merging is running.</p>

 <p>The actual temporary usage could be much less than
 these figures (it depends on many factors).</p>

 <p>In general, once this completes, the total size of the
 index will be less than the size of the starting index.
 It could be quite a bit smaller (if there were many
 pending deletes) or just slightly smaller.</p>

 <p>If an <span class="xref">System.Exception</span> is hit, for example
 due to disk full, the index will not be corrupted and no
 documents will be lost.  However, it may have
 been partially merged (some segments were merged but
 not all), and it&apos;s possible that one of the segments in
 the index will be in non-compound format even when
 using compound file format.  This will occur when the
 <span class="xref">System.Exception</span> is hit during conversion of the segment into
 compound format.</p>

 <p>This call will merge those segments present in
 the index when the call started.  If other threads are
 still adding documents and flushing segments, those
 newly created segments will not be merged unless you
 call <a class="xref" href="Lucene.Net.Index.IndexWriter.html#Lucene_Net_Index_IndexWriter_ForceMerge_System_Int32_">ForceMerge(Int32)</a> again.</p>

 <p><strong>NOTE</strong>: if this method hits an <span class="xref">System.OutOfMemoryException</span>
 you should immediately dispose the writer.  See
 <a class="xref" href="Lucene.Net.Index.IndexWriter.html">IndexWriter</a> for details.</p>

 <p><strong>NOTE</strong>: if you call <a class="xref" href="Lucene.Net.Index.IndexWriter.html#Lucene_Net_Index_IndexWriter_Dispose_System_Boolean_">Dispose(Boolean)</a>
 with <code>false</code>, which aborts all running merges,
 then any thread still running this method might hit a
 <a class="xref" href="Lucene.Net.Index.MergePolicy.MergeAbortedException.html">MergePolicy.MergeAbortedException</a>.</p>
 </div>
   <div class="markdown level1 conceptual"></div>
   <h5 class="decalaration">Declaration</h5>
   <div class="codewrapper">
     <pre><code class="lang-csharp hljs">public virtual void ForceMerge(int maxNumSegments)</code></pre>
   </div>
   <h5 class="parameters">Parameters</h5>
   <table class="table table-bordered table-striped table-condensed">
     <thead>
       <tr>
         <th>Type</th>
         <th>Name</th>
         <th>Description</th>
       </tr>
     </thead>
     <tbody>
       <tr>
         <td><span class="xref">System.Int32</span></td>
         <td><span class="parametername">maxNumSegments</span></td>
         <td><p>maximum number of segments left
 in the index after merging finishes</p>
 </td>
       </tr>
     </tbody>
   </table>
   <h5 class="exceptions">Exceptions</h5>
   <table class="table table-bordered table-striped table-condensed">
     <thead>
       <tr>
         <th>Type</th>
         <th>Condition</th>
       </tr>
     </thead>
     <tbody>
       <tr>
         <td><a class="xref" href="Lucene.Net.Index.CorruptIndexException.html">CorruptIndexException</a></td>
         <td><p>if the index is corrupt </p>
 </td>
       </tr>
       <tr>
         <td><span class="xref">System.IO.IOException</span></td>
         <td><p>if there is a low-level IO error </p>
 </td>
       </tr>
     </tbody>
   </table>
   <h5 id="Lucene_Net_Index_IndexWriter_ForceMerge_System_Int32__seealso">See Also</h5>
   <div class="seealso">
       <div><a class="xref" href="Lucene.Net.Index.MergePolicy.html#Lucene_Net_Index_MergePolicy_FindMerges_Lucene_Net_Index_MergeTrigger_Lucene_Net_Index_SegmentInfos_">FindMerges</a>(<a class="xref" href="Lucene.Net.Index.MergeTrigger.html">MergeTrigger</a>, <a class="xref" href="Lucene.Net.Index.SegmentInfos.html">SegmentInfos</a>)</div>
   </div>
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     <a href="https://github.com/apache/lucenenet/new/docs/4.8.0-beta00010/websites/apidocs/apiSpec/new?filename=Lucene_Net_Index_IndexWriter_ForceMerge_System_Int32_System_Boolean_.md&amp;value=---%0Auid%3A%20Lucene.Net.Index.IndexWriter.ForceMerge(System.Int32%2CSystem.Boolean)%0Asummary%3A%20'*You%20can%20override%20summary%20for%20the%20API%20here%20using%20*MARKDOWN*%20syntax'%0A---%0A%0A*Please%20type%20below%20more%20information%20about%20this%20API%3A*%0A%0A">Improve this Doc</a>
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     <a href="https://github.com/NightOwl888/lucenenet/blob/release/Lucene.Net_4_8_0_beta00010/src/Lucene.Net/Index/IndexWriter.cs/#L2107">View Source</a>
   </span>
   <a id="Lucene_Net_Index_IndexWriter_ForceMerge_" data-uid="Lucene.Net.Index.IndexWriter.ForceMerge*"></a>
   <h4 id="Lucene_Net_Index_IndexWriter_ForceMerge_System_Int32_System_Boolean_" data-uid="Lucene.Net.Index.IndexWriter.ForceMerge(System.Int32,System.Boolean)">ForceMerge(Int32, Boolean)</h4>
   <div class="markdown level1 summary"><p>Just like <a class="xref" href="Lucene.Net.Index.IndexWriter.html#Lucene_Net_Index_IndexWriter_ForceMerge_System_Int32_">ForceMerge(Int32)</a>, except you can
 specify whether the call should block until
 all merging completes.  This is only meaningful with a
 <span class="xref">Lucene.Net.Index.IndexWriter.mergeScheduler</span> that is able to run merges in
 background threads.</p>
 <p><strong>NOTE</strong>: if this method hits an <span class="xref">System.OutOfMemoryException</span>
 you should immediately dispose the writer.  See
 <a class="xref" href="Lucene.Net.Index.IndexWriter.html">IndexWriter</a> for details.</p>
 </div>
   <div class="markdown level1 conceptual"></div>
   <h5 class="decalaration">Declaration</h5>
   <div class="codewrapper">
     <pre><code class="lang-csharp hljs">public virtual void ForceMerge(int maxNumSegments, bool doWait)</code></pre>
   </div>
   <h5 class="parameters">Parameters</h5>
   <table class="table table-bordered table-striped table-condensed">
     <thead>
       <tr>
         <th>Type</th>
         <th>Name</th>
         <th>Description</th>
       </tr>
     </thead>
     <tbody>
       <tr>
         <td><span class="xref">System.Int32</span></td>
         <td><span class="parametername">maxNumSegments</span></td>
         <td></td>
       </tr>
       <tr>
         <td><span class="xref">System.Boolean</span></td>
         <td><span class="parametername">doWait</span></td>
         <td></td>
       </tr>
     </tbody>
   </table>
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     <a href="https://github.com/NightOwl888/lucenenet/blob/release/Lucene.Net_4_8_0_beta00010/src/Lucene.Net/Index/IndexWriter.cs/#L2348">View Source</a>
   </span>
   <a id="Lucene_Net_Index_IndexWriter_ForceMergeDeletes_" data-uid="Lucene.Net.Index.IndexWriter.ForceMergeDeletes*"></a>
   <h4 id="Lucene_Net_Index_IndexWriter_ForceMergeDeletes" data-uid="Lucene.Net.Index.IndexWriter.ForceMergeDeletes">ForceMergeDeletes()</h4>
   <div class="markdown level1 summary"><p>Forces merging of all segments that have deleted
 documents.  The actual merges to be executed are
 determined by the <a class="xref" href="Lucene.Net.Index.MergePolicy.html">MergePolicy</a>.  For example,
 the default <a class="xref" href="Lucene.Net.Index.TieredMergePolicy.html">TieredMergePolicy</a> will only
 pick a segment if the percentage of
 deleted docs is over 10%.</p>
 <p>This is often a horribly costly operation; rarely
 is it warranted.</p>

 <p>To see how
 many deletions you have pending in your index, call
 <a class="xref" href="Lucene.Net.Index.IndexReader.html#Lucene_Net_Index_IndexReader_NumDeletedDocs">NumDeletedDocs</a>.</p>

 <p><strong>NOTE</strong>: this method first flushes a new
 segment (if there are indexed documents), and applies
 all buffered deletes.</p>

 <p><strong>NOTE</strong>: if this method hits an <span class="xref">System.OutOfMemoryException</span>
 you should immediately dispose the writer.  See
 <a class="xref" href="Lucene.Net.Index.IndexWriter.html">IndexWriter</a> for details.</p>
 </div>
   <div class="markdown level1 conceptual"></div>
   <h5 class="decalaration">Declaration</h5>
   <div class="codewrapper">
     <pre><code class="lang-csharp hljs">public virtual void ForceMergeDeletes()</code></pre>
   </div>
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   </span>
   <a id="Lucene_Net_Index_IndexWriter_ForceMergeDeletes_" data-uid="Lucene.Net.Index.IndexWriter.ForceMergeDeletes*"></a>
   <h4 id="Lucene_Net_Index_IndexWriter_ForceMergeDeletes_System_Boolean_" data-uid="Lucene.Net.Index.IndexWriter.ForceMergeDeletes(System.Boolean)">ForceMergeDeletes(Boolean)</h4>
   <div class="markdown level1 summary"><p>Just like <a class="xref" href="Lucene.Net.Index.IndexWriter.html#Lucene_Net_Index_IndexWriter_ForceMergeDeletes">ForceMergeDeletes()</a>, except you can
 specify whether the call should block until the
 operation completes.  This is only meaningful with a
 <a class="xref" href="Lucene.Net.Index.MergeScheduler.html">MergeScheduler</a> that is able to run merges in
 background threads.</p>
 <p><strong>NOTE</strong>: if this method hits an <span class="xref">System.OutOfMemoryException</span>
 you should immediately dispose the writer.  See
 <a class="xref" href="Lucene.Net.Index.IndexWriter.html">IndexWriter</a> for details.</p>

 <p><strong>NOTE</strong>: if you call <a class="xref" href="Lucene.Net.Index.IndexWriter.html#Lucene_Net_Index_IndexWriter_Dispose_System_Boolean_">Dispose(Boolean)</a>
 with <code>false</code>, which aborts all running merges,
 then any thread still running this method might hit a
 <a class="xref" href="Lucene.Net.Index.MergePolicy.MergeAbortedException.html">MergePolicy.MergeAbortedException</a>.</p>
 </div>
   <div class="markdown level1 conceptual"></div>
   <h5 class="decalaration">Declaration</h5>
   <div class="codewrapper">
     <pre><code class="lang-csharp hljs">public virtual void ForceMergeDeletes(bool doWait)</code></pre>
   </div>
   <h5 class="parameters">Parameters</h5>
   <table class="table table-bordered table-striped table-condensed">
     <thead>
       <tr>
         <th>Type</th>
         <th>Name</th>
         <th>Description</th>
       </tr>
     </thead>
     <tbody>
       <tr>
         <td><span class="xref">System.Boolean</span></td>
         <td><span class="parametername">doWait</span></td>
         <td></td>
       </tr>
     </tbody>
   </table>
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   <span class="small pull-right mobile-hide">
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   </span>
   <a id="Lucene_Net_Index_IndexWriter_GetReader_" data-uid="Lucene.Net.Index.IndexWriter.GetReader*"></a>
   <h4 id="Lucene_Net_Index_IndexWriter_GetReader_System_Boolean_" data-uid="Lucene.Net.Index.IndexWriter.GetReader(System.Boolean)">GetReader(Boolean)</h4>
   <div class="markdown level1 summary"><p>Expert: returns a readonly reader, covering all
 committed as well as un-committed changes to the index.
 this provides &quot;near real-time&quot; searching, in that
 changes made during an <a class="xref" href="Lucene.Net.Index.IndexWriter.html">IndexWriter</a> session can be
 quickly made available for searching without closing
 the writer nor calling <a class="xref" href="Lucene.Net.Index.IndexWriter.html#Lucene_Net_Index_IndexWriter_Commit">Commit()</a>.</p>
 <p>Note that this is functionally equivalent to calling
 Flush() and then opening a new reader.  But the turnaround time of this
 method should be faster since it avoids the potentially
 costly <a class="xref" href="Lucene.Net.Index.IndexWriter.html#Lucene_Net_Index_IndexWriter_Commit">Commit()</a>.</p>

 <p>You must close the <a class="xref" href="Lucene.Net.Index.IndexReader.html">IndexReader</a> returned by
 this method once you are done using it.</p>

 <p>It&apos;s <em>near</em> real-time because there is no hard
 guarantee on how quickly you can get a new reader after
 making changes with <a class="xref" href="Lucene.Net.Index.IndexWriter.html">IndexWriter</a>.  You&apos;ll have to
 experiment in your situation to determine if it&apos;s
 fast enough.  As this is a new and experimental
 feature, please report back on your findings so we can
 learn, improve and iterate.</p>

 <p>The resulting reader supports
 <a class="xref" href="Lucene.Net.Index.DirectoryReader.html#Lucene_Net_Index_DirectoryReader_DoOpenIfChanged">DoOpenIfChanged()</a>, but that call will simply forward
 back to this method (though this may change in the
 future).</p>

 <p>The very first time this method is called, this
 writer instance will make every effort to pool the
 readers that it opens for doing merges, applying
 deletes, etc.  This means additional resources (RAM,
 file descriptors, CPU time) will be consumed.</p>

 <p>For lower latency on reopening a reader, you should
 set <a class="xref" href="Lucene.Net.Index.LiveIndexWriterConfig.html#Lucene_Net_Index_LiveIndexWriterConfig_MergedSegmentWarmer">MergedSegmentWarmer</a> to
 pre-warm a newly merged segment before it&apos;s committed
 to the index.  This is important for minimizing
 index-to-search delay after a large merge.  </p>

 <p>If an AddIndexes* call is running in another thread,
 then this reader will only search those segments from
 the foreign index that have been successfully copied
 over, so far.</p>

 <p><strong>NOTE</strong>: Once the writer is disposed, any
 outstanding readers may continue to be used.  However,
 if you attempt to reopen any of those readers, you&apos;ll
 hit an <span class="xref">System.ObjectDisposedException</span>.</p>

 <div class="lucene-block lucene-experimental">This is a Lucene.NET EXPERIMENTAL API, use at your own risk</div></div>
   <div class="markdown level1 conceptual"></div>
   <h5 class="decalaration">Declaration</h5>
   <div class="codewrapper">
     <pre><code class="lang-csharp hljs">public virtual DirectoryReader GetReader(bool applyAllDeletes)</code></pre>
   </div>
   <h5 class="parameters">Parameters</h5>
   <table class="table table-bordered table-striped table-condensed">
     <thead>
       <tr>
         <th>Type</th>
         <th>Name</th>
         <th>Description</th>
       </tr>
     </thead>
     <tbody>
       <tr>
         <td><span class="xref">System.Boolean</span></td>
         <td><span class="parametername">applyAllDeletes</span></td>
         <td></td>
       </tr>
     </tbody>
   </table>
   <h5 class="returns">Returns</h5>
   <table class="table table-bordered table-striped table-condensed">
     <thead>
       <tr>
         <th>Type</th>
         <th>Description</th>
       </tr>
     </thead>
     <tbody>
       <tr>
         <td><a class="xref" href="Lucene.Net.Index.DirectoryReader.html">DirectoryReader</a></td>
         <td><p><a class="xref" href="Lucene.Net.Index.IndexReader.html">IndexReader</a> that covers entire index plus all
     changes made so far by this <a class="xref" href="Lucene.Net.Index.IndexWriter.html">IndexWriter</a> instance</p>
 </td>
       </tr>
     </tbody>
   </table>
   <h5 class="exceptions">Exceptions</h5>
   <table class="table table-bordered table-striped table-condensed">
     <thead>
       <tr>
         <th>Type</th>
         <th>Condition</th>
       </tr>
     </thead>
     <tbody>
       <tr>
         <td><span class="xref">System.IO.IOException</span></td>
         <td><p>If there is a low-level I/O error </p>
 </td>
       </tr>
     </tbody>
   </table>
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   </span>
   <a id="Lucene_Net_Index_IndexWriter_HasDeletions_" data-uid="Lucene.Net.Index.IndexWriter.HasDeletions*"></a>
   <h4 id="Lucene_Net_Index_IndexWriter_HasDeletions" data-uid="Lucene.Net.Index.IndexWriter.HasDeletions">HasDeletions()</h4>
   <div class="markdown level1 summary"><p>Returns <code>true</code> if this index has deletions (including
 buffered deletions).  Note that this will return <code>true</code>
 if there are buffered Term/Query deletions, even if it
 turns out those buffered deletions don&apos;t match any
 documents. Also, if a merge kicked off as a result of flushing a</p>
 </div>
   <div class="markdown level1 conceptual"></div>
   <h5 class="decalaration">Declaration</h5>
   <div class="codewrapper">
     <pre><code class="lang-csharp hljs">public virtual bool HasDeletions()</code></pre>
   </div>
   <h5 class="returns">Returns</h5>
   <table class="table table-bordered table-striped table-condensed">
     <thead>
       <tr>
         <th>Type</th>
         <th>Description</th>
       </tr>
     </thead>
     <tbody>
       <tr>
         <td><span class="xref">System.Boolean</span></td>
         <td></td>
       </tr>
     </tbody>
   </table>
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   </span>
   <a id="Lucene_Net_Index_IndexWriter_HasPendingMerges_" data-uid="Lucene.Net.Index.IndexWriter.HasPendingMerges*"></a>
   <h4 id="Lucene_Net_Index_IndexWriter_HasPendingMerges" data-uid="Lucene.Net.Index.IndexWriter.HasPendingMerges">HasPendingMerges()</h4>
   <div class="markdown level1 summary"><p>Expert: returns true if there are merges waiting to be scheduled.
 <p>
 <div class="lucene-block lucene-experimental">This is a Lucene.NET EXPERIMENTAL API, use at your own risk</div></div>
   <div class="markdown level1 conceptual"></div>
   <h5 class="decalaration">Declaration</h5>
   <div class="codewrapper">
     <pre><code class="lang-csharp hljs">public virtual bool HasPendingMerges()</code></pre>
   </div>
   <h5 class="returns">Returns</h5>
   <table class="table table-bordered table-striped table-condensed">
     <thead>
       <tr>
         <th>Type</th>
         <th>Description</th>
       </tr>
     </thead>
     <tbody>
       <tr>
         <td><span class="xref">System.Boolean</span></td>
         <td></td>
       </tr>
     </tbody>
   </table>
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   </span>
   <a id="Lucene_Net_Index_IndexWriter_HasUncommittedChanges_" data-uid="Lucene.Net.Index.IndexWriter.HasUncommittedChanges*"></a>
   <h4 id="Lucene_Net_Index_IndexWriter_HasUncommittedChanges" data-uid="Lucene.Net.Index.IndexWriter.HasUncommittedChanges">HasUncommittedChanges()</h4>
   <div class="markdown level1 summary"><p>Returns <code>true</code> if there may be changes that have not been
 committed.  There are cases where this may return <code>true</code>
 when there are no actual &quot;real&quot; changes to the index,
 for example if you&apos;ve deleted by <a class="xref" href="Lucene.Net.Index.Term.html">Term</a> or <a class="xref" href="Lucene.Net.Search.Query.html">Query</a> but
 that <a class="xref" href="Lucene.Net.Index.Term.html">Term</a> or <a class="xref" href="Lucene.Net.Search.Query.html">Query</a> does not match any documents.
 Also, if a merge kicked off as a result of flushing a
 new segment during <a class="xref" href="Lucene.Net.Index.IndexWriter.html#Lucene_Net_Index_IndexWriter_Commit">Commit()</a>, or a concurrent
 merged finished, this method may return <code>true</code> right
 after you had just called <a class="xref" href="Lucene.Net.Index.IndexWriter.html#Lucene_Net_Index_IndexWriter_Commit">Commit()</a>.</p>
 </div>
   <div class="markdown level1 conceptual"></div>
   <h5 class="decalaration">Declaration</h5>
   <div class="codewrapper">
     <pre><code class="lang-csharp hljs">public bool HasUncommittedChanges()</code></pre>
   </div>
   <h5 class="returns">Returns</h5>
   <table class="table table-bordered table-striped table-condensed">
     <thead>
       <tr>
         <th>Type</th>
         <th>Description</th>
       </tr>
     </thead>
     <tbody>
       <tr>
         <td><span class="xref">System.Boolean</span></td>
         <td></td>
       </tr>
     </tbody>
   </table>
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   </span>
   <a id="Lucene_Net_Index_IndexWriter_IsLocked_" data-uid="Lucene.Net.Index.IndexWriter.IsLocked*"></a>
   <h4 id="Lucene_Net_Index_IndexWriter_IsLocked_Lucene_Net_Store_Directory_" data-uid="Lucene.Net.Index.IndexWriter.IsLocked(Lucene.Net.Store.Directory)">IsLocked(Directory)</h4>
   <div class="markdown level1 summary"><p>Returns <code>true</code> iff the index in the named directory is
 currently locked. </p>
 </div>
   <div class="markdown level1 conceptual"></div>
   <h5 class="decalaration">Declaration</h5>
   <div class="codewrapper">
     <pre><code class="lang-csharp hljs">public static bool IsLocked(Directory directory)</code></pre>
   </div>
   <h5 class="parameters">Parameters</h5>
   <table class="table table-bordered table-striped table-condensed">
     <thead>
       <tr>
         <th>Type</th>
         <th>Name</th>
         <th>Description</th>
       </tr>
     </thead>
     <tbody>
       <tr>
         <td><a class="xref" href="Lucene.Net.Store.Directory.html">Directory</a></td>
         <td><span class="parametername">directory</span></td>
         <td><p>the directory to check for a lock </p>
 </td>
       </tr>
     </tbody>
   </table>
   <h5 class="returns">Returns</h5>
   <table class="table table-bordered table-striped table-condensed">
     <thead>
       <tr>
         <th>Type</th>
         <th>Description</th>
       </tr>
     </thead>
     <tbody>
       <tr>
         <td><span class="xref">System.Boolean</span></td>
         <td></td>
       </tr>
     </tbody>
   </table>
   <h5 class="exceptions">Exceptions</h5>
   <table class="table table-bordered table-striped table-condensed">
     <thead>
       <tr>
         <th>Type</th>
         <th>Condition</th>
       </tr>
     </thead>
     <tbody>
       <tr>
         <td><span class="xref">System.IO.IOException</span></td>
         <td><p>if there is a low-level IO error </p>
 </td>
       </tr>
     </tbody>
   </table>
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   </span>
   <a id="Lucene_Net_Index_IndexWriter_MaybeMerge_" data-uid="Lucene.Net.Index.IndexWriter.MaybeMerge*"></a>
   <h4 id="Lucene_Net_Index_IndexWriter_MaybeMerge" data-uid="Lucene.Net.Index.IndexWriter.MaybeMerge">MaybeMerge()</h4>
   <div class="markdown level1 summary"><p>Expert: asks the <span class="xref">Lucene.Net.Index.IndexWriter.mergePolicy</span> whether any merges are
 necessary now and if so, runs the requested merges and
 then iterate (test again if merges are needed) until no
 more merges are returned by the <span class="xref">Lucene.Net.Index.IndexWriter.mergePolicy</span>.
 <p>
 Explicit calls to <a class="xref" href="Lucene.Net.Index.IndexWriter.html#Lucene_Net_Index_IndexWriter_MaybeMerge">MaybeMerge()</a> are usually not
 necessary. The most common case is when merge policy
 parameters have changed.
 <p>
 this method will call the <span class="xref">Lucene.Net.Index.IndexWriter.mergePolicy</span> with
 <a class="xref" href="Lucene.Net.Index.MergeTrigger.html#Lucene_Net_Index_MergeTrigger_EXPLICIT">EXPLICIT</a>.</p>
 <p><strong>NOTE</strong>: if this method hits an <span class="xref">System.OutOfMemoryException</span>
 you should immediately dispose the writer.  See
 <a class="xref" href="Lucene.Net.Index.IndexWriter.html">IndexWriter</a> for details.</p>
 </div>
   <div class="markdown level1 conceptual"></div>
   <h5 class="decalaration">Declaration</h5>
   <div class="codewrapper">
     <pre><code class="lang-csharp hljs">public void MaybeMerge()</code></pre>
   </div>
   <span class="small pull-right mobile-hide">
     <span class="divider">|</span>
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   <span class="small pull-right mobile-hide">
     <a href="https://github.com/NightOwl888/lucenenet/blob/release/Lucene.Net_4_8_0_beta00010/src/Lucene.Net/Index/IndexWriter.cs/#L4534">View Source</a>
   </span>
   <a id="Lucene_Net_Index_IndexWriter_Merge_" data-uid="Lucene.Net.Index.IndexWriter.Merge*"></a>
   <h4 id="Lucene_Net_Index_IndexWriter_Merge_Lucene_Net_Index_MergePolicy_OneMerge_" data-uid="Lucene.Net.Index.IndexWriter.Merge(Lucene.Net.Index.MergePolicy.OneMerge)">Merge(MergePolicy.OneMerge)</h4>
   <div class="markdown level1 summary"><p>Merges the indicated segments, replacing them in the stack with a
 single segment.
 <p>
 <div class="lucene-block lucene-experimental">This is a Lucene.NET EXPERIMENTAL API, use at your own risk</div></div>
   <div class="markdown level1 conceptual"></div>
   <h5 class="decalaration">Declaration</h5>
   <div class="codewrapper">
     <pre><code class="lang-csharp hljs">public virtual void Merge(MergePolicy.OneMerge merge)</code></pre>
   </div>
   <h5 class="parameters">Parameters</h5>
   <table class="table table-bordered table-striped table-condensed">
     <thead>
       <tr>
         <th>Type</th>
         <th>Name</th>
         <th>Description</th>
       </tr>
     </thead>
     <tbody>
       <tr>
         <td><a class="xref" href="Lucene.Net.Index.MergePolicy.OneMerge.html">MergePolicy.OneMerge</a></td>
         <td><span class="parametername">merge</span></td>
         <td></td>
       </tr>
     </tbody>
   </table>
   <span class="small pull-right mobile-hide">
     <span class="divider">|</span>
     <a href="https://github.com/apache/lucenenet/new/docs/4.8.0-beta00010/websites/apidocs/apiSpec/new?filename=Lucene_Net_Index_IndexWriter_MergeFinish_Lucene_Net_Index_MergePolicy_OneMerge_.md&amp;value=---%0Auid%3A%20Lucene.Net.Index.IndexWriter.MergeFinish(Lucene.Net.Index.MergePolicy.OneMerge)%0Asummary%3A%20'*You%20can%20override%20summary%20for%20the%20API%20here%20using%20*MARKDOWN*%20syntax'%0A---%0A%0A*Please%20type%20below%20more%20information%20about%20this%20API%3A*%0A%0A">Improve this Doc</a>
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     <a href="https://github.com/NightOwl888/lucenenet/blob/release/Lucene.Net_4_8_0_beta00010/src/Lucene.Net/Index/IndexWriter.cs/#L4863">View Source</a>
   </span>
   <a id="Lucene_Net_Index_IndexWriter_MergeFinish_" data-uid="Lucene.Net.Index.IndexWriter.MergeFinish*"></a>
   <h4 id="Lucene_Net_Index_IndexWriter_MergeFinish_Lucene_Net_Index_MergePolicy_OneMerge_" data-uid="Lucene.Net.Index.IndexWriter.MergeFinish(Lucene.Net.Index.MergePolicy.OneMerge)">MergeFinish(MergePolicy.OneMerge)</h4>
   <div class="markdown level1 summary"><p>Does fininishing for a merge, which is fast but holds
 the synchronized lock on <a class="xref" href="Lucene.Net.Index.IndexWriter.html">IndexWriter</a> instance.</p>
 </div>
   <div class="markdown level1 conceptual"></div>
   <h5 class="decalaration">Declaration</h5>
   <div class="codewrapper">
     <pre><code class="lang-csharp hljs">public void MergeFinish(MergePolicy.OneMerge merge)</code></pre>
   </div>
   <h5 class="parameters">Parameters</h5>
   <table class="table table-bordered table-striped table-condensed">
     <thead>
       <tr>
         <th>Type</th>
         <th>Name</th>
         <th>Description</th>
       </tr>
     </thead>
     <tbody>
       <tr>
         <td><a class="xref" href="Lucene.Net.Index.MergePolicy.OneMerge.html">MergePolicy.OneMerge</a></td>
         <td><span class="parametername">merge</span></td>
         <td></td>
       </tr>
     </tbody>
   </table>
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     <span class="divider">|</span>
     <a href="https://github.com/apache/lucenenet/new/docs/4.8.0-beta00010/websites/apidocs/apiSpec/new?filename=Lucene_Net_Index_IndexWriter_NextMerge.md&amp;value=---%0Auid%3A%20Lucene.Net.Index.IndexWriter.NextMerge%0Asummary%3A%20'*You%20can%20override%20summary%20for%20the%20API%20here%20using%20*MARKDOWN*%20syntax'%0A---%0A%0A*Please%20type%20below%20more%20information%20about%20this%20API%3A*%0A%0A">Improve this Doc</a>
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   <span class="small pull-right mobile-hide">
     <a href="https://github.com/NightOwl888/lucenenet/blob/release/Lucene.Net_4_8_0_beta00010/src/Lucene.Net/Index/IndexWriter.cs/#L2459">View Source</a>
   </span>
   <a id="Lucene_Net_Index_IndexWriter_NextMerge_" data-uid="Lucene.Net.Index.IndexWriter.NextMerge*"></a>
   <h4 id="Lucene_Net_Index_IndexWriter_NextMerge" data-uid="Lucene.Net.Index.IndexWriter.NextMerge">NextMerge()</h4>
   <div class="markdown level1 summary"><p>Expert: the <span class="xref">Lucene.Net.Index.IndexWriter.mergeScheduler</span> calls this method to retrieve the next
 merge requested by the <a class="xref" href="Lucene.Net.Index.MergePolicy.html">MergePolicy</a>
 <p>
 <div class="lucene-block lucene-experimental">This is a Lucene.NET EXPERIMENTAL API, use at your own risk</div></div>
   <div class="markdown level1 conceptual"></div>
   <h5 class="decalaration">Declaration</h5>
   <div class="codewrapper">
     <pre><code class="lang-csharp hljs">public virtual MergePolicy.OneMerge NextMerge()</code></pre>
   </div>
   <h5 class="returns">Returns</h5>
   <table class="table table-bordered table-striped table-condensed">
     <thead>
       <tr>
         <th>Type</th>
         <th>Description</th>
       </tr>
     </thead>
     <tbody>
       <tr>
         <td><a class="xref" href="Lucene.Net.Index.MergePolicy.OneMerge.html">MergePolicy.OneMerge</a></td>
         <td></td>
       </tr>
     </tbody>
   </table>
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   </span>
   <a id="Lucene_Net_Index_IndexWriter_NumDeletedDocs_" data-uid="Lucene.Net.Index.IndexWriter.NumDeletedDocs*"></a>
   <h4 id="Lucene_Net_Index_IndexWriter_NumDeletedDocs_Lucene_Net_Index_SegmentCommitInfo_" data-uid="Lucene.Net.Index.IndexWriter.NumDeletedDocs(Lucene.Net.Index.SegmentCommitInfo)">NumDeletedDocs(SegmentCommitInfo)</h4>
   <div class="markdown level1 summary"><p>Obtain the number of deleted docs for a pooled reader.
 If the reader isn&apos;t being pooled, the segmentInfo&apos;s
 delCount is returned.</p>
 </div>
   <div class="markdown level1 conceptual"></div>
   <h5 class="decalaration">Declaration</h5>
   <div class="codewrapper">
     <pre><code class="lang-csharp hljs">public virtual int NumDeletedDocs(SegmentCommitInfo info)</code></pre>
   </div>
   <h5 class="parameters">Parameters</h5>
   <table class="table table-bordered table-striped table-condensed">
     <thead>
       <tr>
         <th>Type</th>
         <th>Name</th>
         <th>Description</th>
       </tr>
     </thead>
     <tbody>
       <tr>
         <td><a class="xref" href="Lucene.Net.Index.SegmentCommitInfo.html">SegmentCommitInfo</a></td>
         <td><span class="parametername">info</span></td>
         <td></td>
       </tr>
     </tbody>
   </table>
   <h5 class="returns">Returns</h5>
   <table class="table table-bordered table-striped table-condensed">
     <thead>
       <tr>
         <th>Type</th>
         <th>Description</th>
       </tr>
     </thead>
     <tbody>
       <tr>
         <td><span class="xref">System.Int32</span></td>
         <td></td>
       </tr>
     </tbody>
   </table>
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   </span>
   <a id="Lucene_Net_Index_IndexWriter_NumRamDocs_" data-uid="Lucene.Net.Index.IndexWriter.NumRamDocs*"></a>
   <h4 id="Lucene_Net_Index_IndexWriter_NumRamDocs" data-uid="Lucene.Net.Index.IndexWriter.NumRamDocs">NumRamDocs()</h4>
   <div class="markdown level1 summary"><p>Expert:  Return the number of documents currently
 buffered in RAM.</p>
 </div>
   <div class="markdown level1 conceptual"></div>
   <h5 class="decalaration">Declaration</h5>
   <div class="codewrapper">
     <pre><code class="lang-csharp hljs">public int NumRamDocs()</code></pre>
   </div>
   <h5 class="returns">Returns</h5>
   <table class="table table-bordered table-striped table-condensed">
     <thead>
       <tr>
         <th>Type</th>
         <th>Description</th>
       </tr>
     </thead>
     <tbody>
       <tr>
         <td><span class="xref">System.Int32</span></td>
         <td></td>
       </tr>
     </tbody>
   </table>
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   </span>
   <a id="Lucene_Net_Index_IndexWriter_PrepareCommit_" data-uid="Lucene.Net.Index.IndexWriter.PrepareCommit*"></a>
   <h4 id="Lucene_Net_Index_IndexWriter_PrepareCommit" data-uid="Lucene.Net.Index.IndexWriter.PrepareCommit">PrepareCommit()</h4>
   <div class="markdown level1 summary"><p>Expert: prepare for commit.  This does the
 first phase of 2-phase commit. this method does all
 steps necessary to commit changes since this writer
 was opened: flushes pending added and deleted docs,
 syncs the index files, writes most of next segments_N
 file.  After calling this you must call either
 <a class="xref" href="Lucene.Net.Index.IndexWriter.html#Lucene_Net_Index_IndexWriter_Commit">Commit()</a> to finish the commit, or
 <a class="xref" href="Lucene.Net.Index.IndexWriter.html#Lucene_Net_Index_IndexWriter_Rollback">Rollback()</a> to revert the commit and undo all changes
 done since the writer was opened.</p>

 <p>You can also just call <a class="xref" href="Lucene.Net.Index.IndexWriter.html#Lucene_Net_Index_IndexWriter_Commit">Commit()</a> directly
 without <a class="xref" href="Lucene.Net.Index.IndexWriter.html#Lucene_Net_Index_IndexWriter_PrepareCommit">PrepareCommit()</a> first in which case that method
 will internally call <a class="xref" href="Lucene.Net.Index.IndexWriter.html#Lucene_Net_Index_IndexWriter_PrepareCommit">PrepareCommit()</a>.</p>

 <p><strong>NOTE</strong>: if this method hits an <span class="xref">System.OutOfMemoryException</span>
 you should immediately dispose the writer.  See
 <a class="xref" href="Lucene.Net.Index.IndexWriter.html">IndexWriter</a> for details.</p>
 </div>
   <div class="markdown level1 conceptual"></div>
   <h5 class="decalaration">Declaration</h5>
   <div class="codewrapper">
     <pre><code class="lang-csharp hljs">public void PrepareCommit()</code></pre>
   </div>
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   </span>
   <a id="Lucene_Net_Index_IndexWriter_RamSizeInBytes_" data-uid="Lucene.Net.Index.IndexWriter.RamSizeInBytes*"></a>
   <h4 id="Lucene_Net_Index_IndexWriter_RamSizeInBytes" data-uid="Lucene.Net.Index.IndexWriter.RamSizeInBytes">RamSizeInBytes()</h4>
   <div class="markdown level1 summary"><p>Expert:  Return the total size of all index files currently cached in memory.
 Useful for size management with flushRamDocs()</p>
 </div>
   <div class="markdown level1 conceptual"></div>
   <h5 class="decalaration">Declaration</h5>
   <div class="codewrapper">
     <pre><code class="lang-csharp hljs">public long RamSizeInBytes()</code></pre>
   </div>
   <h5 class="returns">Returns</h5>
   <table class="table table-bordered table-striped table-condensed">
     <thead>
       <tr>
         <th>Type</th>
         <th>Description</th>
       </tr>
     </thead>
     <tbody>
       <tr>
         <td><span class="xref">System.Int64</span></td>
         <td></td>
       </tr>
     </tbody>
   </table>
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   </span>
   <a id="Lucene_Net_Index_IndexWriter_Rollback_" data-uid="Lucene.Net.Index.IndexWriter.Rollback*"></a>
   <h4 id="Lucene_Net_Index_IndexWriter_Rollback" data-uid="Lucene.Net.Index.IndexWriter.Rollback">Rollback()</h4>
   <div class="markdown level1 summary"><p>Close the <a class="xref" href="Lucene.Net.Index.IndexWriter.html">IndexWriter</a> without committing
 any changes that have occurred since the last commit
 (or since it was opened, if commit hasn&apos;t been called).
 this removes any temporary files that had been created,
 after which the state of the index will be the same as
 it was when <a class="xref" href="Lucene.Net.Index.IndexWriter.html#Lucene_Net_Index_IndexWriter_Commit">Commit()</a> was last called or when this
 writer was first opened.  This also clears a previous
 call to <a class="xref" href="Lucene.Net.Index.IndexWriter.html#Lucene_Net_Index_IndexWriter_PrepareCommit">PrepareCommit()</a>.</p>
 </div>
   <div class="markdown level1 conceptual"></div>
   <h5 class="decalaration">Declaration</h5>
   <div class="codewrapper">
     <pre><code class="lang-csharp hljs">public virtual void Rollback()</code></pre>
   </div>
   <h5 class="exceptions">Exceptions</h5>
   <table class="table table-bordered table-striped table-condensed">
     <thead>
       <tr>
         <th>Type</th>
         <th>Condition</th>
       </tr>
     </thead>
     <tbody>
       <tr>
         <td><span class="xref">System.IO.IOException</span></td>
         <td><p>if there is a low-level IO error </p>
 </td>
       </tr>
     </tbody>
   </table>
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   </span>
   <a id="Lucene_Net_Index_IndexWriter_SegString_" data-uid="Lucene.Net.Index.IndexWriter.SegString*"></a>
   <h4 id="Lucene_Net_Index_IndexWriter_SegString" data-uid="Lucene.Net.Index.IndexWriter.SegString">SegString()</h4>
   <div class="markdown level1 summary"><p>Returns a string description of all segments, for
 debugging.
 <p>
 <div class="lucene-block lucene-internal">This is a Lucene.NET INTERNAL API, use at your own risk</div></div>
   <div class="markdown level1 conceptual"></div>
   <h5 class="decalaration">Declaration</h5>
   <div class="codewrapper">
     <pre><code class="lang-csharp hljs">public virtual string SegString()</code></pre>
   </div>
   <h5 class="returns">Returns</h5>
   <table class="table table-bordered table-striped table-condensed">
     <thead>
       <tr>
         <th>Type</th>
         <th>Description</th>
       </tr>
     </thead>
     <tbody>
       <tr>
         <td><span class="xref">System.String</span></td>
         <td></td>
       </tr>
     </tbody>
   </table>
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   </span>
   <a id="Lucene_Net_Index_IndexWriter_SegString_" data-uid="Lucene.Net.Index.IndexWriter.SegString*"></a>
   <h4 id="Lucene_Net_Index_IndexWriter_SegString_Lucene_Net_Index_SegmentCommitInfo_" data-uid="Lucene.Net.Index.IndexWriter.SegString(Lucene.Net.Index.SegmentCommitInfo)">SegString(SegmentCommitInfo)</h4>
   <div class="markdown level1 summary"><p>Returns a string description of the specified
 segment, for debugging.
 <p>
 <div class="lucene-block lucene-internal">This is a Lucene.NET INTERNAL API, use at your own risk</div></div>
   <div class="markdown level1 conceptual"></div>
   <h5 class="decalaration">Declaration</h5>
   <div class="codewrapper">
     <pre><code class="lang-csharp hljs">public virtual string SegString(SegmentCommitInfo info)</code></pre>
   </div>
   <h5 class="parameters">Parameters</h5>
   <table class="table table-bordered table-striped table-condensed">
     <thead>
       <tr>
         <th>Type</th>
         <th>Name</th>
         <th>Description</th>
       </tr>
     </thead>
     <tbody>
       <tr>
         <td><a class="xref" href="Lucene.Net.Index.SegmentCommitInfo.html">SegmentCommitInfo</a></td>
         <td><span class="parametername">info</span></td>
         <td></td>
       </tr>
     </tbody>
   </table>
   <h5 class="returns">Returns</h5>
   <table class="table table-bordered table-striped table-condensed">
     <thead>
       <tr>
         <th>Type</th>
         <th>Description</th>
       </tr>
     </thead>
     <tbody>
       <tr>
         <td><span class="xref">System.String</span></td>
         <td></td>
       </tr>
     </tbody>
   </table>
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   </span>
   <a id="Lucene_Net_Index_IndexWriter_SegString_" data-uid="Lucene.Net.Index.IndexWriter.SegString*"></a>
   <h4 id="Lucene_Net_Index_IndexWriter_SegString_System_Collections_Generic_IEnumerable_Lucene_Net_Index_SegmentCommitInfo__" data-uid="Lucene.Net.Index.IndexWriter.SegString(System.Collections.Generic.IEnumerable{Lucene.Net.Index.SegmentCommitInfo})">SegString(IEnumerable&lt;SegmentCommitInfo&gt;)</h4>
   <div class="markdown level1 summary"><p>Returns a string description of the specified
 segments, for debugging.
 <p>
 <div class="lucene-block lucene-internal">This is a Lucene.NET INTERNAL API, use at your own risk</div></div>
   <div class="markdown level1 conceptual"></div>
   <h5 class="decalaration">Declaration</h5>
   <div class="codewrapper">
     <pre><code class="lang-csharp hljs">public virtual string SegString(IEnumerable&lt;SegmentCommitInfo&gt; infos)</code></pre>
   </div>
   <h5 class="parameters">Parameters</h5>
   <table class="table table-bordered table-striped table-condensed">
     <thead>
       <tr>
         <th>Type</th>
         <th>Name</th>
         <th>Description</th>
       </tr>
     </thead>
     <tbody>
       <tr>
         <td><span class="xref">System.Collections.Generic.IEnumerable</span>&lt;<a class="xref" href="Lucene.Net.Index.SegmentCommitInfo.html">SegmentCommitInfo</a>&gt;</td>
         <td><span class="parametername">infos</span></td>
         <td></td>
       </tr>
     </tbody>
   </table>
   <h5 class="returns">Returns</h5>
   <table class="table table-bordered table-striped table-condensed">
     <thead>
       <tr>
         <th>Type</th>
         <th>Description</th>
       </tr>
     </thead>
     <tbody>
       <tr>
         <td><span class="xref">System.String</span></td>
         <td></td>
       </tr>
     </tbody>
   </table>
   <span class="small pull-right mobile-hide">
     <span class="divider">|</span>
     <a href="https://github.com/apache/lucenenet/new/docs/4.8.0-beta00010/websites/apidocs/apiSpec/new?filename=Lucene_Net_Index_IndexWriter_SetCommitData_System_Collections_Generic_IDictionary_System_String_System_String__.md&amp;value=---%0Auid%3A%20Lucene.Net.Index.IndexWriter.SetCommitData(System.Collections.Generic.IDictionary%7BSystem.String%2CSystem.String%7D)%0Asummary%3A%20'*You%20can%20override%20summary%20for%20the%20API%20here%20using%20*MARKDOWN*%20syntax'%0A---%0A%0A*Please%20type%20below%20more%20information%20about%20this%20API%3A*%0A%0A">Improve this Doc</a>
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   </span>
   <a id="Lucene_Net_Index_IndexWriter_SetCommitData_" data-uid="Lucene.Net.Index.IndexWriter.SetCommitData*"></a>
   <h4 id="Lucene_Net_Index_IndexWriter_SetCommitData_System_Collections_Generic_IDictionary_System_String_System_String__" data-uid="Lucene.Net.Index.IndexWriter.SetCommitData(System.Collections.Generic.IDictionary{System.String,System.String})">SetCommitData(IDictionary&lt;String, String&gt;)</h4>
   <div class="markdown level1 summary"><p>Sets the commit user data map. That method is considered a transaction by
 <a class="xref" href="Lucene.Net.Index.IndexWriter.html">IndexWriter</a> and will be committed (<a class="xref" href="Lucene.Net.Index.IndexWriter.html#Lucene_Net_Index_IndexWriter_Commit">Commit()</a> even if no other
 changes were made to the writer instance. Note that you must call this method
 before <a class="xref" href="Lucene.Net.Index.IndexWriter.html#Lucene_Net_Index_IndexWriter_PrepareCommit">PrepareCommit()</a>, or otherwise it won&apos;t be included in the
 follow-on <a class="xref" href="Lucene.Net.Index.IndexWriter.html#Lucene_Net_Index_IndexWriter_Commit">Commit()</a>.
 <p>
 <strong>NOTE:</strong> the dictionary is cloned internally, therefore altering the dictionary&apos;s
 contents after calling this method has no effect.</p>
 </div>
   <div class="markdown level1 conceptual"></div>
   <h5 class="decalaration">Declaration</h5>
   <div class="codewrapper">
     <pre><code class="lang-csharp hljs">public void SetCommitData(IDictionary&lt;string, string&gt; commitUserData)</code></pre>
   </div>
   <h5 class="parameters">Parameters</h5>
   <table class="table table-bordered table-striped table-condensed">
     <thead>
       <tr>
         <th>Type</th>
         <th>Name</th>
         <th>Description</th>
       </tr>
     </thead>
     <tbody>
       <tr>
         <td><span class="xref">System.Collections.Generic.IDictionary</span>&lt;<span class="xref">System.String</span>, <span class="xref">System.String</span>&gt;</td>
         <td><span class="parametername">commitUserData</span></td>
         <td></td>
       </tr>
     </tbody>
   </table>
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     <a href="https://github.com/apache/lucenenet/new/docs/4.8.0-beta00010/websites/apidocs/apiSpec/new?filename=Lucene_Net_Index_IndexWriter_TryDeleteDocument_Lucene_Net_Index_IndexReader_System_Int32_.md&amp;value=---%0Auid%3A%20Lucene.Net.Index.IndexWriter.TryDeleteDocument(Lucene.Net.Index.IndexReader%2CSystem.Int32)%0Asummary%3A%20'*You%20can%20override%20summary%20for%20the%20API%20here%20using%20*MARKDOWN*%20syntax'%0A---%0A%0A*Please%20type%20below%20more%20information%20about%20this%20API%3A*%0A%0A">Improve this Doc</a>
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   </span>
   <a id="Lucene_Net_Index_IndexWriter_TryDeleteDocument_" data-uid="Lucene.Net.Index.IndexWriter.TryDeleteDocument*"></a>
   <h4 id="Lucene_Net_Index_IndexWriter_TryDeleteDocument_Lucene_Net_Index_IndexReader_System_Int32_" data-uid="Lucene.Net.Index.IndexWriter.TryDeleteDocument(Lucene.Net.Index.IndexReader,System.Int32)">TryDeleteDocument(IndexReader, Int32)</h4>
   <div class="markdown level1 summary"><p>Expert: attempts to delete by document ID, as long as
 the provided <code data-dev-comment-type="paramref" class="paramref">readerIn</code> is a near-real-time reader (from
 <a class="xref" href="Lucene.Net.Index.DirectoryReader.html#Lucene_Net_Index_DirectoryReader_Open_Lucene_Net_Index_IndexWriter_System_Boolean_">Open(IndexWriter, Boolean)</a>.  If the
 provided <code data-dev-comment-type="paramref" class="paramref">readerIn</code> is an NRT reader obtained from this
 writer, and its segment has not been merged away, then
 the delete succeeds and this method returns <code>true</code>; else, it
 returns <code>false</code> the caller must then separately delete by
 Term or Query.</p>
 <p><strong>NOTE</strong>: this method can only delete documents
 visible to the currently open NRT reader.  If you need
 to delete documents indexed after opening the NRT
 reader you must use the other DeleteDocument() methods
 (e.g., <a class="xref" href="Lucene.Net.Index.IndexWriter.html#Lucene_Net_Index_IndexWriter_DeleteDocuments_Lucene_Net_Index_Term_">DeleteDocuments(Term)</a>).</p>
 </div>
   <div class="markdown level1 conceptual"></div>
   <h5 class="decalaration">Declaration</h5>
   <div class="codewrapper">
     <pre><code class="lang-csharp hljs">public virtual bool TryDeleteDocument(IndexReader readerIn, int docID)</code></pre>
   </div>
   <h5 class="parameters">Parameters</h5>
   <table class="table table-bordered table-striped table-condensed">
     <thead>
       <tr>
         <th>Type</th>
         <th>Name</th>
         <th>Description</th>
       </tr>
     </thead>
     <tbody>
       <tr>
         <td><a class="xref" href="Lucene.Net.Index.IndexReader.html">IndexReader</a></td>
         <td><span class="parametername">readerIn</span></td>
         <td></td>
       </tr>
       <tr>
         <td><span class="xref">System.Int32</span></td>
         <td><span class="parametername">docID</span></td>
         <td></td>
       </tr>
     </tbody>
   </table>
   <h5 class="returns">Returns</h5>
   <table class="table table-bordered table-striped table-condensed">
     <thead>
       <tr>
         <th>Type</th>
         <th>Description</th>
       </tr>
     </thead>
     <tbody>
       <tr>
         <td><span class="xref">System.Boolean</span></td>
         <td></td>
       </tr>
     </tbody>
   </table>
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     <a href="https://github.com/apache/lucenenet/new/docs/4.8.0-beta00010/websites/apidocs/apiSpec/new?filename=Lucene_Net_Index_IndexWriter_Unlock_Lucene_Net_Store_Directory_.md&amp;value=---%0Auid%3A%20Lucene.Net.Index.IndexWriter.Unlock(Lucene.Net.Store.Directory)%0Asummary%3A%20'*You%20can%20override%20summary%20for%20the%20API%20here%20using%20*MARKDOWN*%20syntax'%0A---%0A%0A*Please%20type%20below%20more%20information%20about%20this%20API%3A*%0A%0A">Improve this Doc</a>
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   </span>
   <a id="Lucene_Net_Index_IndexWriter_Unlock_" data-uid="Lucene.Net.Index.IndexWriter.Unlock*"></a>
   <h4 id="Lucene_Net_Index_IndexWriter_Unlock_Lucene_Net_Store_Directory_" data-uid="Lucene.Net.Index.IndexWriter.Unlock(Lucene.Net.Store.Directory)">Unlock(Directory)</h4>
   <div class="markdown level1 summary"><p>Forcibly unlocks the index in the named directory.
 <p>
 Caution: this should only be used by failure recovery code,
 when it is known that no other process nor thread is in fact
 currently accessing this index.</p>
 </div>
   <div class="markdown level1 conceptual"></div>
   <h5 class="decalaration">Declaration</h5>
   <div class="codewrapper">
     <pre><code class="lang-csharp hljs">public static void Unlock(Directory directory)</code></pre>
   </div>
   <h5 class="parameters">Parameters</h5>
   <table class="table table-bordered table-striped table-condensed">
     <thead>
       <tr>
         <th>Type</th>
         <th>Name</th>
         <th>Description</th>
       </tr>
     </thead>
     <tbody>
       <tr>
         <td><a class="xref" href="Lucene.Net.Store.Directory.html">Directory</a></td>
         <td><span class="parametername">directory</span></td>
         <td></td>
       </tr>
     </tbody>
   </table>
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     <a href="https://github.com/apache/lucenenet/new/docs/4.8.0-beta00010/websites/apidocs/apiSpec/new?filename=Lucene_Net_Index_IndexWriter_UpdateBinaryDocValue_Lucene_Net_Index_Term_System_String_Lucene_Net_Util_BytesRef_.md&amp;value=---%0Auid%3A%20Lucene.Net.Index.IndexWriter.UpdateBinaryDocValue(Lucene.Net.Index.Term%2CSystem.String%2CLucene.Net.Util.BytesRef)%0Asummary%3A%20'*You%20can%20override%20summary%20for%20the%20API%20here%20using%20*MARKDOWN*%20syntax'%0A---%0A%0A*Please%20type%20below%20more%20information%20about%20this%20API%3A*%0A%0A">Improve this Doc</a>
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   </span>
   <a id="Lucene_Net_Index_IndexWriter_UpdateBinaryDocValue_" data-uid="Lucene.Net.Index.IndexWriter.UpdateBinaryDocValue*"></a>
   <h4 id="Lucene_Net_Index_IndexWriter_UpdateBinaryDocValue_Lucene_Net_Index_Term_System_String_Lucene_Net_Util_BytesRef_" data-uid="Lucene.Net.Index.IndexWriter.UpdateBinaryDocValue(Lucene.Net.Index.Term,System.String,Lucene.Net.Util.BytesRef)">UpdateBinaryDocValue(Term, String, BytesRef)</h4>
   <div class="markdown level1 summary"><p>Updates a document&apos;s <a class="xref" href="Lucene.Net.Index.BinaryDocValues.html">BinaryDocValues</a> for <code data-dev-comment-type="paramref" class="paramref">field</code> to the
 given <code data-dev-comment-type="paramref" class="paramref">value</code>. this method can be used to &apos;unset&apos; a document&apos;s
 value by passing <code>null</code> as the new <code data-dev-comment-type="paramref" class="paramref">value</code>. Also, you can only update
 fields that already exist in the index, not add new fields through this
 method.</p>
 <p>
 <strong>NOTE:</strong> this method currently replaces the existing value of all
 affected documents with the new value.

 <p>
 <strong>NOTE:</strong> if this method hits an <span class="xref">System.OutOfMemoryException</span> you should immediately
 dispose the writer. See <a class="xref" href="Lucene.Net.Index.IndexWriter.html">IndexWriter</a> for details.
 </p>
 </div>
   <div class="markdown level1 conceptual"></div>
   <h5 class="decalaration">Declaration</h5>
   <div class="codewrapper">
     <pre><code class="lang-csharp hljs">public virtual void UpdateBinaryDocValue(Term term, string field, BytesRef value)</code></pre>
   </div>
   <h5 class="parameters">Parameters</h5>
   <table class="table table-bordered table-striped table-condensed">
     <thead>
       <tr>
         <th>Type</th>
         <th>Name</th>
         <th>Description</th>
       </tr>
     </thead>
     <tbody>
       <tr>
         <td><a class="xref" href="Lucene.Net.Index.Term.html">Term</a></td>
         <td><span class="parametername">term</span></td>
         <td><p>the term to identify the document(s) to be updated </p>
 </td>
       </tr>
       <tr>
         <td><span class="xref">System.String</span></td>
         <td><span class="parametername">field</span></td>
         <td><p>field name of the <a class="xref" href="Lucene.Net.Index.BinaryDocValues.html">BinaryDocValues</a> field </p>
 </td>
       </tr>
       <tr>
         <td><a class="xref" href="Lucene.Net.Util.BytesRef.html">BytesRef</a></td>
         <td><span class="parametername">value</span></td>
         <td><p>new value for the field </p>
 </td>
       </tr>
     </tbody>
   </table>
   <h5 class="exceptions">Exceptions</h5>
   <table class="table table-bordered table-striped table-condensed">
     <thead>
       <tr>
         <th>Type</th>
         <th>Condition</th>
       </tr>
     </thead>
     <tbody>
       <tr>
         <td><a class="xref" href="Lucene.Net.Index.CorruptIndexException.html">CorruptIndexException</a></td>
         <td><p>if the index is corrupt </p>
 </td>
       </tr>
       <tr>
         <td><span class="xref">System.IO.IOException</span></td>
         <td><p>if there is a low-level IO error </p>
 </td>
       </tr>
     </tbody>
   </table>
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   </span>
   <a id="Lucene_Net_Index_IndexWriter_UpdateDocument_" data-uid="Lucene.Net.Index.IndexWriter.UpdateDocument*"></a>
   <h4 id="Lucene_Net_Index_IndexWriter_UpdateDocument_Lucene_Net_Index_Term_System_Collections_Generic_IEnumerable_Lucene_Net_Index_IIndexableField__" data-uid="Lucene.Net.Index.IndexWriter.UpdateDocument(Lucene.Net.Index.Term,System.Collections.Generic.IEnumerable{Lucene.Net.Index.IIndexableField})">UpdateDocument(Term, IEnumerable&lt;IIndexableField&gt;)</h4>
   <div class="markdown level1 summary"><p>Updates a document by first deleting the document(s)
 containing <code data-dev-comment-type="paramref" class="paramref">term</code> and then adding the new
 document.  The delete and then add are atomic as seen
 by a reader on the same index (flush may happen only after
 the add).</p>
 <p><strong>NOTE</strong>: if this method hits an <span class="xref">System.OutOfMemoryException</span>
 you should immediately dispose the writer.  See
 <a class="xref" href="Lucene.Net.Index.IndexWriter.html">IndexWriter</a> for details.</p>
 </div>
   <div class="markdown level1 conceptual"></div>
   <h5 class="decalaration">Declaration</h5>
   <div class="codewrapper">
     <pre><code class="lang-csharp hljs">public virtual void UpdateDocument(Term term, IEnumerable&lt;IIndexableField&gt; doc)</code></pre>
   </div>
   <h5 class="parameters">Parameters</h5>
   <table class="table table-bordered table-striped table-condensed">
     <thead>
       <tr>
         <th>Type</th>
         <th>Name</th>
         <th>Description</th>
       </tr>
     </thead>
     <tbody>
       <tr>
         <td><a class="xref" href="Lucene.Net.Index.Term.html">Term</a></td>
         <td><span class="parametername">term</span></td>
         <td><p>the term to identify the document(s) to be
 deleted </p>
 </td>
       </tr>
       <tr>
         <td><span class="xref">System.Collections.Generic.IEnumerable</span>&lt;<a class="xref" href="Lucene.Net.Index.IIndexableField.html">IIndexableField</a>&gt;</td>
         <td><span class="parametername">doc</span></td>
         <td><p>the document to be added </p>
 </td>
       </tr>
     </tbody>
   </table>
   <h5 class="exceptions">Exceptions</h5>
   <table class="table table-bordered table-striped table-condensed">
     <thead>
       <tr>
         <th>Type</th>
         <th>Condition</th>
       </tr>
     </thead>
     <tbody>
       <tr>
         <td><a class="xref" href="Lucene.Net.Index.CorruptIndexException.html">CorruptIndexException</a></td>
         <td><p>if the index is corrupt </p>
 </td>
       </tr>
       <tr>
         <td><span class="xref">System.IO.IOException</span></td>
         <td><p>if there is a low-level IO error </p>
 </td>
       </tr>
     </tbody>
   </table>
   <span class="small pull-right mobile-hide">
     <span class="divider">|</span>
     <a href="https://github.com/apache/lucenenet/new/docs/4.8.0-beta00010/websites/apidocs/apiSpec/new?filename=Lucene_Net_Index_IndexWriter_UpdateDocument_Lucene_Net_Index_Term_System_Collections_Generic_IEnumerable_Lucene_Net_Index_IIndexableField__Lucene_Net_Analysis_Analyzer_.md&amp;value=---%0Auid%3A%20Lucene.Net.Index.IndexWriter.UpdateDocument(Lucene.Net.Index.Term%2CSystem.Collections.Generic.IEnumerable%7BLucene.Net.Index.IIndexableField%7D%2CLucene.Net.Analysis.Analyzer)%0Asummary%3A%20'*You%20can%20override%20summary%20for%20the%20API%20here%20using%20*MARKDOWN*%20syntax'%0A---%0A%0A*Please%20type%20below%20more%20information%20about%20this%20API%3A*%0A%0A">Improve this Doc</a>
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   </span>
   <a id="Lucene_Net_Index_IndexWriter_UpdateDocument_" data-uid="Lucene.Net.Index.IndexWriter.UpdateDocument*"></a>
   <h4 id="Lucene_Net_Index_IndexWriter_UpdateDocument_Lucene_Net_Index_Term_System_Collections_Generic_IEnumerable_Lucene_Net_Index_IIndexableField__Lucene_Net_Analysis_Analyzer_" data-uid="Lucene.Net.Index.IndexWriter.UpdateDocument(Lucene.Net.Index.Term,System.Collections.Generic.IEnumerable{Lucene.Net.Index.IIndexableField},Lucene.Net.Analysis.Analyzer)">UpdateDocument(Term, IEnumerable&lt;IIndexableField&gt;, Analyzer)</h4>
   <div class="markdown level1 summary"><p>Updates a document by first deleting the document(s)
 containing <code data-dev-comment-type="paramref" class="paramref">term</code> and then adding the new
 document.  The delete and then add are atomic as seen
 by a reader on the same index (flush may happen only after
 the add).</p>
 <p><strong>NOTE</strong>: if this method hits an <span class="xref">System.OutOfMemoryException</span>
 you should immediately dispose the writer.  See
 <a class="xref" href="Lucene.Net.Index.IndexWriter.html">IndexWriter</a> for details.</p>
 </div>
   <div class="markdown level1 conceptual"></div>
   <h5 class="decalaration">Declaration</h5>
   <div class="codewrapper">
     <pre><code class="lang-csharp hljs">public virtual void UpdateDocument(Term term, IEnumerable&lt;IIndexableField&gt; doc, Analyzer analyzer)</code></pre>
   </div>
   <h5 class="parameters">Parameters</h5>
   <table class="table table-bordered table-striped table-condensed">
     <thead>
       <tr>
         <th>Type</th>
         <th>Name</th>
         <th>Description</th>
       </tr>
     </thead>
     <tbody>
       <tr>
         <td><a class="xref" href="Lucene.Net.Index.Term.html">Term</a></td>
         <td><span class="parametername">term</span></td>
         <td><p>the term to identify the document(s) to be
 deleted </p>
 </td>
       </tr>
       <tr>
         <td><span class="xref">System.Collections.Generic.IEnumerable</span>&lt;<a class="xref" href="Lucene.Net.Index.IIndexableField.html">IIndexableField</a>&gt;</td>
         <td><span class="parametername">doc</span></td>
         <td><p>the document to be added </p>
 </td>
       </tr>
       <tr>
         <td><a class="xref" href="Lucene.Net.Analysis.Analyzer.html">Analyzer</a></td>
         <td><span class="parametername">analyzer</span></td>
         <td><p>the analyzer to use when analyzing the document </p>
 </td>
       </tr>
     </tbody>
   </table>
   <h5 class="exceptions">Exceptions</h5>
   <table class="table table-bordered table-striped table-condensed">
     <thead>
       <tr>
         <th>Type</th>
         <th>Condition</th>
       </tr>
     </thead>
     <tbody>
       <tr>
         <td><a class="xref" href="Lucene.Net.Index.CorruptIndexException.html">CorruptIndexException</a></td>
         <td><p>if the index is corrupt </p>
 </td>
       </tr>
       <tr>
         <td><span class="xref">System.IO.IOException</span></td>
         <td><p>if there is a low-level IO error </p>
 </td>
       </tr>
     </tbody>
   </table>
   <span class="small pull-right mobile-hide">
     <span class="divider">|</span>
     <a href="https://github.com/apache/lucenenet/new/docs/4.8.0-beta00010/websites/apidocs/apiSpec/new?filename=Lucene_Net_Index_IndexWriter_UpdateDocuments_Lucene_Net_Index_Term_System_Collections_Generic_IEnumerable_System_Collections_Generic_IEnumerable_Lucene_Net_Index_IIndexableField___.md&amp;value=---%0Auid%3A%20Lucene.Net.Index.IndexWriter.UpdateDocuments(Lucene.Net.Index.Term%2CSystem.Collections.Generic.IEnumerable%7BSystem.Collections.Generic.IEnumerable%7BLucene.Net.Index.IIndexableField%7D%7D)%0Asummary%3A%20'*You%20can%20override%20summary%20for%20the%20API%20here%20using%20*MARKDOWN*%20syntax'%0A---%0A%0A*Please%20type%20below%20more%20information%20about%20this%20API%3A*%0A%0A">Improve this Doc</a>
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   <span class="small pull-right mobile-hide">
     <a href="https://github.com/NightOwl888/lucenenet/blob/release/Lucene.Net_4_8_0_beta00010/src/Lucene.Net/Index/IndexWriter.cs/#L1538">View Source</a>
   </span>
   <a id="Lucene_Net_Index_IndexWriter_UpdateDocuments_" data-uid="Lucene.Net.Index.IndexWriter.UpdateDocuments*"></a>
   <h4 id="Lucene_Net_Index_IndexWriter_UpdateDocuments_Lucene_Net_Index_Term_System_Collections_Generic_IEnumerable_System_Collections_Generic_IEnumerable_Lucene_Net_Index_IIndexableField___" data-uid="Lucene.Net.Index.IndexWriter.UpdateDocuments(Lucene.Net.Index.Term,System.Collections.Generic.IEnumerable{System.Collections.Generic.IEnumerable{Lucene.Net.Index.IIndexableField}})">UpdateDocuments(Term, IEnumerable&lt;IEnumerable&lt;IIndexableField&gt;&gt;)</h4>
   <div class="markdown level1 summary"><p>Atomically deletes documents matching the provided
 <code data-dev-comment-type="paramref" class="paramref">delTerm</code> and adds a block of documents with sequentially
 assigned document IDs, such that an external reader
 will see all or none of the documents.
 <p>
 <div class="lucene-block lucene-experimental">This is a Lucene.NET EXPERIMENTAL API, use at your own risk</div></div>
   <div class="markdown level1 conceptual"></div>
   <h5 class="decalaration">Declaration</h5>
   <div class="codewrapper">
     <pre><code class="lang-csharp hljs">public virtual void UpdateDocuments(Term delTerm, IEnumerable&lt;IEnumerable&lt;IIndexableField&gt;&gt; docs)</code></pre>
   </div>
   <h5 class="parameters">Parameters</h5>
   <table class="table table-bordered table-striped table-condensed">
     <thead>
       <tr>
         <th>Type</th>
         <th>Name</th>
         <th>Description</th>
       </tr>
     </thead>
     <tbody>
       <tr>
         <td><a class="xref" href="Lucene.Net.Index.Term.html">Term</a></td>
         <td><span class="parametername">delTerm</span></td>
         <td></td>
       </tr>
       <tr>
         <td><span class="xref">System.Collections.Generic.IEnumerable</span>&lt;<span class="xref">System.Collections.Generic.IEnumerable</span>&lt;<a class="xref" href="Lucene.Net.Index.IIndexableField.html">IIndexableField</a>&gt;&gt;</td>
         <td><span class="parametername">docs</span></td>
         <td></td>
       </tr>
     </tbody>
   </table>
   <h5 class="exceptions">Exceptions</h5>
   <table class="table table-bordered table-striped table-condensed">
     <thead>
       <tr>
         <th>Type</th>
         <th>Condition</th>
       </tr>
     </thead>
     <tbody>
       <tr>
         <td><a class="xref" href="Lucene.Net.Index.CorruptIndexException.html">CorruptIndexException</a></td>
         <td><p>if the index is corrupt </p>
 </td>
       </tr>
       <tr>
         <td><span class="xref">System.IO.IOException</span></td>
         <td><p>if there is a low-level IO error </p>
 </td>
       </tr>
     </tbody>
   </table>
   <h5 id="Lucene_Net_Index_IndexWriter_UpdateDocuments_Lucene_Net_Index_Term_System_Collections_Generic_IEnumerable_System_Collections_Generic_IEnumerable_Lucene_Net_Index_IIndexableField____seealso">See Also</h5>
   <div class="seealso">
       <div><a class="xref" href="Lucene.Net.Index.IndexWriter.html#Lucene_Net_Index_IndexWriter_AddDocuments_System_Collections_Generic_IEnumerable_System_Collections_Generic_IEnumerable_Lucene_Net_Index_IIndexableField___">AddDocuments(IEnumerable&lt;IEnumerable&lt;IIndexableField&gt;&gt;)</a></div>
   </div>
   <span class="small pull-right mobile-hide">
     <span class="divider">|</span>
     <a href="https://github.com/apache/lucenenet/new/docs/4.8.0-beta00010/websites/apidocs/apiSpec/new?filename=Lucene_Net_Index_IndexWriter_UpdateDocuments_Lucene_Net_Index_Term_System_Collections_Generic_IEnumerable_System_Collections_Generic_IEnumerable_Lucene_Net_Index_IIndexableField___Lucene_Net_Analysis_Analyzer_.md&amp;value=---%0Auid%3A%20Lucene.Net.Index.IndexWriter.UpdateDocuments(Lucene.Net.Index.Term%2CSystem.Collections.Generic.IEnumerable%7BSystem.Collections.Generic.IEnumerable%7BLucene.Net.Index.IIndexableField%7D%7D%2CLucene.Net.Analysis.Analyzer)%0Asummary%3A%20'*You%20can%20override%20summary%20for%20the%20API%20here%20using%20*MARKDOWN*%20syntax'%0A---%0A%0A*Please%20type%20below%20more%20information%20about%20this%20API%3A*%0A%0A">Improve this Doc</a>
   </span>
   <span class="small pull-right mobile-hide">
     <a href="https://github.com/NightOwl888/lucenenet/blob/release/Lucene.Net_4_8_0_beta00010/src/Lucene.Net/Index/IndexWriter.cs/#L1555">View Source</a>
   </span>
   <a id="Lucene_Net_Index_IndexWriter_UpdateDocuments_" data-uid="Lucene.Net.Index.IndexWriter.UpdateDocuments*"></a>
   <h4 id="Lucene_Net_Index_IndexWriter_UpdateDocuments_Lucene_Net_Index_Term_System_Collections_Generic_IEnumerable_System_Collections_Generic_IEnumerable_Lucene_Net_Index_IIndexableField___Lucene_Net_Analysis_Analyzer_" data-uid="Lucene.Net.Index.IndexWriter.UpdateDocuments(Lucene.Net.Index.Term,System.Collections.Generic.IEnumerable{System.Collections.Generic.IEnumerable{Lucene.Net.Index.IIndexableField}},Lucene.Net.Analysis.Analyzer)">UpdateDocuments(Term, IEnumerable&lt;IEnumerable&lt;IIndexableField&gt;&gt;, Analyzer)</h4>
   <div class="markdown level1 summary"><p>Atomically deletes documents matching the provided
 <code data-dev-comment-type="paramref" class="paramref">delTerm</code> and adds a block of documents, analyzed using
 the provided <code data-dev-comment-type="paramref" class="paramref">analyzer</code>, with sequentially
 assigned document IDs, such that an external reader
 will see all or none of the documents.
 <p>
 <div class="lucene-block lucene-experimental">This is a Lucene.NET EXPERIMENTAL API, use at your own risk</div></div>
   <div class="markdown level1 conceptual"></div>
   <h5 class="decalaration">Declaration</h5>
   <div class="codewrapper">
     <pre><code class="lang-csharp hljs">public virtual void UpdateDocuments(Term delTerm, IEnumerable&lt;IEnumerable&lt;IIndexableField&gt;&gt; docs, Analyzer analyzer)</code></pre>
   </div>
   <h5 class="parameters">Parameters</h5>
   <table class="table table-bordered table-striped table-condensed">
     <thead>
       <tr>
         <th>Type</th>
         <th>Name</th>
         <th>Description</th>
       </tr>
     </thead>
     <tbody>
       <tr>
         <td><a class="xref" href="Lucene.Net.Index.Term.html">Term</a></td>
         <td><span class="parametername">delTerm</span></td>
         <td></td>
       </tr>
       <tr>
         <td><span class="xref">System.Collections.Generic.IEnumerable</span>&lt;<span class="xref">System.Collections.Generic.IEnumerable</span>&lt;<a class="xref" href="Lucene.Net.Index.IIndexableField.html">IIndexableField</a>&gt;&gt;</td>
         <td><span class="parametername">docs</span></td>
         <td></td>
       </tr>
       <tr>
         <td><a class="xref" href="Lucene.Net.Analysis.Analyzer.html">Analyzer</a></td>
         <td><span class="parametername">analyzer</span></td>
         <td></td>
       </tr>
     </tbody>
   </table>
   <h5 class="exceptions">Exceptions</h5>
   <table class="table table-bordered table-striped table-condensed">
     <thead>
       <tr>
         <th>Type</th>
         <th>Condition</th>
       </tr>
     </thead>
     <tbody>
       <tr>
         <td><a class="xref" href="Lucene.Net.Index.CorruptIndexException.html">CorruptIndexException</a></td>
         <td><p>if the index is corrupt </p>
 </td>
       </tr>
       <tr>
         <td><span class="xref">System.IO.IOException</span></td>
         <td><p>if there is a low-level IO error </p>
 </td>
       </tr>
     </tbody>
   </table>
   <h5 id="Lucene_Net_Index_IndexWriter_UpdateDocuments_Lucene_Net_Index_Term_System_Collections_Generic_IEnumerable_System_Collections_Generic_IEnumerable_Lucene_Net_Index_IIndexableField___Lucene_Net_Analysis_Analyzer__seealso">See Also</h5>
   <div class="seealso">
       <div><a class="xref" href="Lucene.Net.Index.IndexWriter.html#Lucene_Net_Index_IndexWriter_AddDocuments_System_Collections_Generic_IEnumerable_System_Collections_Generic_IEnumerable_Lucene_Net_Index_IIndexableField___">AddDocuments(IEnumerable&lt;IEnumerable&lt;IIndexableField&gt;&gt;)</a></div>
   </div>
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     <span class="divider">|</span>
     <a href="https://github.com/apache/lucenenet/new/docs/4.8.0-beta00010/websites/apidocs/apiSpec/new?filename=Lucene_Net_Index_IndexWriter_UpdateNumericDocValue_Lucene_Net_Index_Term_System_String_System_Nullable_System_Int64__.md&amp;value=---%0Auid%3A%20Lucene.Net.Index.IndexWriter.UpdateNumericDocValue(Lucene.Net.Index.Term%2CSystem.String%2CSystem.Nullable%7BSystem.Int64%7D)%0Asummary%3A%20'*You%20can%20override%20summary%20for%20the%20API%20here%20using%20*MARKDOWN*%20syntax'%0A---%0A%0A*Please%20type%20below%20more%20information%20about%20this%20API%3A*%0A%0A">Improve this Doc</a>
   </span>
   <span class="small pull-right mobile-hide">
     <a href="https://github.com/NightOwl888/lucenenet/blob/release/Lucene.Net_4_8_0_beta00010/src/Lucene.Net/Index/IndexWriter.cs/#L1882">View Source</a>
   </span>
   <a id="Lucene_Net_Index_IndexWriter_UpdateNumericDocValue_" data-uid="Lucene.Net.Index.IndexWriter.UpdateNumericDocValue*"></a>
   <h4 id="Lucene_Net_Index_IndexWriter_UpdateNumericDocValue_Lucene_Net_Index_Term_System_String_System_Nullable_System_Int64__" data-uid="Lucene.Net.Index.IndexWriter.UpdateNumericDocValue(Lucene.Net.Index.Term,System.String,System.Nullable{System.Int64})">UpdateNumericDocValue(Term, String, Nullable&lt;Int64&gt;)</h4>
   <div class="markdown level1 summary"><p>Updates a document&apos;s <a class="xref" href="Lucene.Net.Index.NumericDocValues.html">NumericDocValues</a> for <code data-dev-comment-type="paramref" class="paramref">field</code> to the
 given <code data-dev-comment-type="paramref" class="paramref">value</code>. This method can be used to &apos;unset&apos; a document&apos;s
 value by passing <code>null</code> as the new <code data-dev-comment-type="paramref" class="paramref">value</code>. Also, you can only update
 fields that already exist in the index, not add new fields through this
 method.</p>
 <p>
 <strong>NOTE</strong>: if this method hits an <span class="xref">System.OutOfMemoryException</span> you should immediately
 dispose the writer. See <a class="xref" href="Lucene.Net.Index.IndexWriter.html">IndexWriter</a> for details.
 </p>
 </div>
   <div class="markdown level1 conceptual"></div>
   <h5 class="decalaration">Declaration</h5>
   <div class="codewrapper">
     <pre><code class="lang-csharp hljs">public virtual void UpdateNumericDocValue(Term term, string field, long? value)</code></pre>
   </div>
   <h5 class="parameters">Parameters</h5>
   <table class="table table-bordered table-striped table-condensed">
     <thead>
       <tr>
         <th>Type</th>
         <th>Name</th>
         <th>Description</th>
       </tr>
     </thead>
     <tbody>
       <tr>
         <td><a class="xref" href="Lucene.Net.Index.Term.html">Term</a></td>
         <td><span class="parametername">term</span></td>
         <td><p>the term to identify the document(s) to be updated </p>
 </td>
       </tr>
       <tr>
         <td><span class="xref">System.String</span></td>
         <td><span class="parametername">field</span></td>
         <td><p>field name of the <a class="xref" href="Lucene.Net.Index.NumericDocValues.html">NumericDocValues</a> field </p>
 </td>
       </tr>
       <tr>
         <td><span class="xref">System.Nullable</span>&lt;<span class="xref">System.Int64</span>&gt;</td>
         <td><span class="parametername">value</span></td>
         <td><p>new value for the field </p>
 </td>
       </tr>
     </tbody>
   </table>
   <h5 class="exceptions">Exceptions</h5>
   <table class="table table-bordered table-striped table-condensed">
     <thead>
       <tr>
         <th>Type</th>
         <th>Condition</th>
       </tr>
     </thead>
     <tbody>
       <tr>
         <td><a class="xref" href="Lucene.Net.Index.CorruptIndexException.html">CorruptIndexException</a></td>
         <td><p>if the index is corrupt </p>
 </td>
       </tr>
       <tr>
         <td><span class="xref">System.IO.IOException</span></td>
         <td><p>if there is a low-level IO error </p>
 </td>
       </tr>
     </tbody>
   </table>
   <span class="small pull-right mobile-hide">
     <span class="divider">|</span>
     <a href="https://github.com/apache/lucenenet/new/docs/4.8.0-beta00010/websites/apidocs/apiSpec/new?filename=Lucene_Net_Index_IndexWriter_WaitForMerges.md&amp;value=---%0Auid%3A%20Lucene.Net.Index.IndexWriter.WaitForMerges%0Asummary%3A%20'*You%20can%20override%20summary%20for%20the%20API%20here%20using%20*MARKDOWN*%20syntax'%0A---%0A%0A*Please%20type%20below%20more%20information%20about%20this%20API%3A*%0A%0A">Improve this Doc</a>
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   <span class="small pull-right mobile-hide">
     <a href="https://github.com/NightOwl888/lucenenet/blob/release/Lucene.Net_4_8_0_beta00010/src/Lucene.Net/Index/IndexWriter.cs/#L2799">View Source</a>
   </span>
   <a id="Lucene_Net_Index_IndexWriter_WaitForMerges_" data-uid="Lucene.Net.Index.IndexWriter.WaitForMerges*"></a>
   <h4 id="Lucene_Net_Index_IndexWriter_WaitForMerges" data-uid="Lucene.Net.Index.IndexWriter.WaitForMerges">WaitForMerges()</h4>
   <div class="markdown level1 summary"><p>Wait for any currently outstanding merges to finish.</p>
 <p>It is guaranteed that any merges started prior to calling this method
    will have completed once this method completes.</p>
 </div>
   <div class="markdown level1 conceptual"></div>
   <h5 class="decalaration">Declaration</h5>
   <div class="codewrapper">
     <pre><code class="lang-csharp hljs">public virtual void WaitForMerges()</code></pre>
   </div>
   <h3 id="implements">Implements</h3>
   <div>
       <span class="xref">System.IDisposable</span>
   </div>
   <div>
       <a class="xref" href="Lucene.Net.Index.ITwoPhaseCommit.html">ITwoPhaseCommit</a>
   </div>
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