apidocs/org/apache/calcite/rel/AbstractRelNode.html - calcite-site - Git at Google

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 <div class="subTitle"><span class="packageLabelInType">Package</span>&nbsp;<a href="package-summary.html">org.apache.calcite.rel</a></div>
 <h2 title="Class AbstractRelNode" class="title">Class AbstractRelNode</h2>
 </div>
 <div class="contentContainer">
 <ul class="inheritance">
 <li>java.lang.Object</li>
 <li>
 <ul class="inheritance">
 <li>org.apache.calcite.rel.AbstractRelNode</li>
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 <dt>All Implemented Interfaces:</dt>
 <dd><code>java.lang.Cloneable</code>, <code><a href="../plan/RelOptNode.html" title="interface in org.apache.calcite.plan">RelOptNode</a></code>, <code><a href="RelNode.html" title="interface in org.apache.calcite.rel">RelNode</a></code></dd>
 </dl>
 <dl>
 <dt>Direct Known Subclasses:</dt>
 <dd><code><a href="BiRel.html" title="class in org.apache.calcite.rel">BiRel</a></code>, <code><a href="../adapter/druid/DruidQuery.html" title="class in org.apache.calcite.adapter.druid">DruidQuery</a></code>, <code><a href="../plan/hep/HepRelVertex.html" title="class in org.apache.calcite.plan.hep">HepRelVertex</a></code>, <code><a href="rules/MultiJoin.html" title="class in org.apache.calcite.rel.rules">MultiJoin</a></code>, <code><a href="../plan/volcano/RelSubset.html" title="class in org.apache.calcite.plan.volcano">RelSubset</a></code>, <code><a href="core/SetOp.html" title="class in org.apache.calcite.rel.core">SetOp</a></code>, <code><a href="SingleRel.html" title="class in org.apache.calcite.rel">SingleRel</a></code>, <code><a href="core/TableFunctionScan.html" title="class in org.apache.calcite.rel.core">TableFunctionScan</a></code>, <code><a href="core/TableScan.html" title="class in org.apache.calcite.rel.core">TableScan</a></code>, <code><a href="core/Values.html" title="class in org.apache.calcite.rel.core">Values</a></code></dd>
 </dl>
 <hr>
 <pre>public abstract class <span class="typeNameLabel">AbstractRelNode</span>
 extends java.lang.Object
 implements <a href="RelNode.html" title="interface in org.apache.calcite.rel">RelNode</a></pre>
 <div class="block">Base class for every relational expression (<a href="RelNode.html" title="interface in org.apache.calcite.rel"><code>RelNode</code></a>).</div>
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 <h3>Nested Class Summary</h3>
 <table class="memberSummary">
 <caption><span>Nested Classes</span><span class="tabEnd">&nbsp;</span></caption>
 <tr>
 <th class="colFirst" scope="col">Modifier and Type</th>
 <th class="colSecond" scope="col">Class</th>
 <th class="colLast" scope="col">Description</th>
 </tr>
 <tr class="altColor">
 <td class="colFirst"><code>private static class&nbsp;</code></td>
 <th class="colSecond" scope="row"><code><span class="memberNameLink"><a href="AbstractRelNode.RelDigestWriter.html" title="class in org.apache.calcite.rel">AbstractRelNode.RelDigestWriter</a></span></code></th>
 <td class="colLast">
 <div class="block">A writer object used exclusively for computing the digest of a RelNode.</div>
 </td>
 </tr>
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 <!--   -->
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 <h3>Nested classes/interfaces inherited from interface&nbsp;org.apache.calcite.rel.<a href="RelNode.html" title="interface in org.apache.calcite.rel">RelNode</a></h3>
 <code><a href="RelNode.Context.html" title="interface in org.apache.calcite.rel">RelNode.Context</a></code></li>
 </ul>
 </li>
 </ul>
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 <h3>Field Summary</h3>
 <table class="memberSummary">
 <caption><span>Fields</span><span class="tabEnd">&nbsp;</span></caption>
 <tr>
 <th class="colFirst" scope="col">Modifier and Type</th>
 <th class="colSecond" scope="col">Field</th>
 <th class="colLast" scope="col">Description</th>
 </tr>
 <tr class="altColor">
 <td class="colFirst"><code>private <a href="../plan/RelOptCluster.html" title="class in org.apache.calcite.plan">RelOptCluster</a></code></td>
 <th class="colSecond" scope="row"><code><span class="memberNameLink"><a href="#cluster">cluster</a></span></code></th>
 <td class="colLast">&nbsp;</td>
 </tr>
 <tr class="rowColor">
 <td class="colFirst"><code>private java.lang.String</code></td>
 <th class="colSecond" scope="row"><code><span class="memberNameLink"><a href="#desc">desc</a></span></code></th>
 <td class="colLast">
 <div class="block">Description, consists of id plus digest.</div>
 </td>
 </tr>
 <tr class="altColor">
 <td class="colFirst"><code>protected java.lang.String</code></td>
 <th class="colSecond" scope="row"><code><span class="memberNameLink"><a href="#digest">digest</a></span></code></th>
 <td class="colLast">
 <div class="block">A short description of this relational expression's type, inputs, and
  other properties.</div>
 </td>
 </tr>
 <tr class="rowColor">
 <td class="colFirst"><code>protected int</code></td>
 <th class="colSecond" scope="row"><code><span class="memberNameLink"><a href="#id">id</a></span></code></th>
 <td class="colLast">
 <div class="block">unique id of this object -- for debugging</div>
 </td>
 </tr>
 <tr class="altColor">
 <td class="colFirst"><code>private static org.slf4j.Logger</code></td>
 <th class="colSecond" scope="row"><code><span class="memberNameLink"><a href="#LOGGER">LOGGER</a></span></code></th>
 <td class="colLast">&nbsp;</td>
 </tr>
 <tr class="rowColor">
 <td class="colFirst"><code>private static java.util.concurrent.atomic.AtomicInteger</code></td>
 <th class="colSecond" scope="row"><code><span class="memberNameLink"><a href="#NEXT_ID">NEXT_ID</a></span></code></th>
 <td class="colLast">
 <div class="block">Generator for <a href="#id"><code>id</code></a> values.</div>
 </td>
 </tr>
 <tr class="altColor">
 <td class="colFirst"><code>protected <a href="type/RelDataType.html" title="interface in org.apache.calcite.rel.type">RelDataType</a></code></td>
 <th class="colSecond" scope="row"><code><span class="memberNameLink"><a href="#rowType">rowType</a></span></code></th>
 <td class="colLast">
 <div class="block">Cached type of this relational expression.</div>
 </td>
 </tr>
 <tr class="rowColor">
 <td class="colFirst"><code>protected <a href="../plan/RelTraitSet.html" title="class in org.apache.calcite.plan">RelTraitSet</a></code></td>
 <th class="colSecond" scope="row"><code><span class="memberNameLink"><a href="#traitSet">traitSet</a></span></code></th>
 <td class="colLast">
 <div class="block">The RelTraitSet that describes the traits of this RelNode.</div>
 </td>
 </tr>
 </table>
 </li>
 </ul>
 </section>
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 <h3>Constructor Summary</h3>
 <table class="memberSummary">
 <caption><span>Constructors</span><span class="tabEnd">&nbsp;</span></caption>
 <tr>
 <th class="colFirst" scope="col">Constructor</th>
 <th class="colLast" scope="col">Description</th>
 </tr>
 <tr class="altColor">
 <th class="colConstructorName" scope="row"><code><span class="memberNameLink"><a href="#%3Cinit%3E(org.apache.calcite.plan.RelOptCluster,org.apache.calcite.plan.RelTraitSet)">AbstractRelNode</a></span>&#8203;(<a href="../plan/RelOptCluster.html" title="class in org.apache.calcite.plan">RelOptCluster</a>&nbsp;cluster,
                <a href="../plan/RelTraitSet.html" title="class in org.apache.calcite.plan">RelTraitSet</a>&nbsp;traitSet)</code></th>
 <td class="colLast">
 <div class="block">Creates an <code>AbstractRelNode</code>.</div>
 </td>
 </tr>
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 </li>
 </ul>
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 <h3>Method Summary</h3>
 <table class="memberSummary">
 <caption><span id="t0" class="activeTableTab"><span>All Methods</span><span class="tabEnd">&nbsp;</span></span><span id="t1" class="tableTab"><span><a href="javascript:show(1);">Static Methods</a></span><span class="tabEnd">&nbsp;</span></span><span id="t2" class="tableTab"><span><a href="javascript:show(2);">Instance Methods</a></span><span class="tabEnd">&nbsp;</span></span><span id="t4" class="tableTab"><span><a href="javascript:show(8);">Concrete Methods</a></span><span class="tabEnd">&nbsp;</span></span><span id="t6" class="tableTab"><span><a href="javascript:show(32);">Deprecated Methods</a></span><span class="tabEnd">&nbsp;</span></span></caption>
 <tr>
 <th class="colFirst" scope="col">Modifier and Type</th>
 <th class="colSecond" scope="col">Method</th>
 <th class="colLast" scope="col">Description</th>
 </tr>
 <tr id="i0" class="altColor">
 <td class="colFirst"><code><a href="RelNode.html" title="interface in org.apache.calcite.rel">RelNode</a></code></td>
 <th class="colSecond" scope="row"><code><span class="memberNameLink"><a href="#accept(org.apache.calcite.rel.RelShuttle)">accept</a></span>&#8203;(<a href="RelShuttle.html" title="interface in org.apache.calcite.rel">RelShuttle</a>&nbsp;shuttle)</code></th>
 <td class="colLast">
 <div class="block">Accepts a visit from a shuttle.</div>
 </td>
 </tr>
 <tr id="i1" class="rowColor">
 <td class="colFirst"><code><a href="RelNode.html" title="interface in org.apache.calcite.rel">RelNode</a></code></td>
 <th class="colSecond" scope="row"><code><span class="memberNameLink"><a href="#accept(org.apache.calcite.rex.RexShuttle)">accept</a></span>&#8203;(<a href="../rex/RexShuttle.html" title="class in org.apache.calcite.rex">RexShuttle</a>&nbsp;shuttle)</code></th>
 <td class="colLast">
 <div class="block">Accepts a visit from a shuttle.</div>
 </td>
 </tr>
 <tr id="i2" class="altColor">
 <td class="colFirst"><code>void</code></td>
 <th class="colSecond" scope="row"><code><span class="memberNameLink"><a href="#childrenAccept(org.apache.calcite.rel.RelVisitor)">childrenAccept</a></span>&#8203;(<a href="RelVisitor.html" title="class in org.apache.calcite.rel">RelVisitor</a>&nbsp;visitor)</code></th>
 <td class="colLast">
 <div class="block">Interacts with the <a href="RelVisitor.html" title="class in org.apache.calcite.rel"><code>RelVisitor</code></a> in a
  <a href="../util/Glossary.html#VISITOR_PATTERN"><code>visitor pattern</code></a> to
  traverse the tree of relational expressions.</div>
 </td>
 </tr>
 <tr id="i3" class="rowColor">
 <td class="colFirst"><code>void</code></td>
 <th class="colSecond" scope="row"><code><span class="memberNameLink"><a href="#collectVariablesSet(java.util.Set)">collectVariablesSet</a></span>&#8203;(java.util.Set&lt;<a href="core/CorrelationId.html" title="class in org.apache.calcite.rel.core">CorrelationId</a>&gt;&nbsp;variableSet)</code></th>
 <td class="colLast">
 <div class="block">Collects variables set by this expression.</div>
 </td>
 </tr>
 <tr id="i4" class="altColor">
 <td class="colFirst"><code>void</code></td>
 <th class="colSecond" scope="row"><code><span class="memberNameLink"><a href="#collectVariablesUsed(java.util.Set)">collectVariablesUsed</a></span>&#8203;(java.util.Set&lt;<a href="core/CorrelationId.html" title="class in org.apache.calcite.rel.core">CorrelationId</a>&gt;&nbsp;variableSet)</code></th>
 <td class="colLast">
 <div class="block">Collects variables known to be used by this expression or its
  descendants.</div>
 </td>
 </tr>
 <tr id="i5" class="rowColor">
 <td class="colFirst"><code>protected java.lang.String</code></td>
 <th class="colSecond" scope="row"><code><span class="memberNameLink"><a href="#computeDigest()">computeDigest</a></span>()</code></th>
 <td class="colLast">
 <div class="block">Computes the digest.</div>
 </td>
 </tr>
 <tr id="i6" class="altColor">
 <td class="colFirst"><code><a href="../plan/RelOptCost.html" title="interface in org.apache.calcite.plan">RelOptCost</a></code></td>
 <th class="colSecond" scope="row"><code><span class="memberNameLink"><a href="#computeSelfCost(org.apache.calcite.plan.RelOptPlanner)">computeSelfCost</a></span>&#8203;(<a href="../plan/RelOptPlanner.html" title="interface in org.apache.calcite.plan">RelOptPlanner</a>&nbsp;planner)</code></th>
 <td class="colLast">&nbsp;</td>
 </tr>
 <tr id="i7" class="rowColor">
 <td class="colFirst"><code><a href="../plan/RelOptCost.html" title="interface in org.apache.calcite.plan">RelOptCost</a></code></td>
 <th class="colSecond" scope="row"><code><span class="memberNameLink"><a href="#computeSelfCost(org.apache.calcite.plan.RelOptPlanner,org.apache.calcite.rel.metadata.RelMetadataQuery)">computeSelfCost</a></span>&#8203;(<a href="../plan/RelOptPlanner.html" title="interface in org.apache.calcite.plan">RelOptPlanner</a>&nbsp;planner,
                <a href="metadata/RelMetadataQuery.html" title="class in org.apache.calcite.rel.metadata">RelMetadataQuery</a>&nbsp;mq)</code></th>
 <td class="colLast">
 <div class="block">Returns the cost of this plan (not including children).</div>
 </td>
 </tr>
 <tr id="i8" class="altColor">
 <td class="colFirst"><code><a href="RelNode.html" title="interface in org.apache.calcite.rel">RelNode</a></code></td>
 <th class="colSecond" scope="row"><code><span class="memberNameLink"><a href="#copy(org.apache.calcite.plan.RelTraitSet,java.util.List)">copy</a></span>&#8203;(<a href="../plan/RelTraitSet.html" title="class in org.apache.calcite.plan">RelTraitSet</a>&nbsp;traitSet,
     java.util.List&lt;<a href="RelNode.html" title="interface in org.apache.calcite.rel">RelNode</a>&gt;&nbsp;inputs)</code></th>
 <td class="colLast">
 <div class="block">Creates a copy of this relational expression, perhaps changing traits and
  inputs.</div>
 </td>
 </tr>
 <tr id="i9" class="rowColor">
 <td class="colFirst"><code>protected <a href="type/RelDataType.html" title="interface in org.apache.calcite.rel.type">RelDataType</a></code></td>
 <th class="colSecond" scope="row"><code><span class="memberNameLink"><a href="#deriveRowType()">deriveRowType</a></span>()</code></th>
 <td class="colLast">&nbsp;</td>
 </tr>
 <tr id="i10" class="altColor">
 <td class="colFirst"><code>boolean</code></td>
 <th class="colSecond" scope="row"><code><span class="memberNameLink"><a href="#equals(java.lang.Object)">equals</a></span>&#8203;(java.lang.Object&nbsp;obj)</code></th>
 </tr>
 <tr id="i11" class="rowColor">
 <td class="colFirst"><code>double</code></td>
 <th class="colSecond" scope="row"><code><span class="memberNameLink"><a href="#estimateRowCount(org.apache.calcite.rel.metadata.RelMetadataQuery)">estimateRowCount</a></span>&#8203;(<a href="metadata/RelMetadataQuery.html" title="class in org.apache.calcite.rel.metadata">RelMetadataQuery</a>&nbsp;mq)</code></th>
 <td class="colLast">
 <div class="block">Returns an estimate of the number of rows this relational expression will
  return.</div>
 </td>
 </tr>
 <tr id="i12" class="altColor">
 <td class="colFirst"><code>void</code></td>
 <th class="colSecond" scope="row"><code><span class="memberNameLink"><a href="#explain(org.apache.calcite.rel.RelWriter)">explain</a></span>&#8203;(<a href="RelWriter.html" title="interface in org.apache.calcite.rel">RelWriter</a>&nbsp;pw)</code></th>
 <td class="colLast">
 <div class="block">Describes the inputs and attributes of this relational expression.</div>
 </td>
 </tr>
 <tr id="i13" class="rowColor">
 <td class="colFirst"><code><a href="RelWriter.html" title="interface in org.apache.calcite.rel">RelWriter</a></code></td>
 <th class="colSecond" scope="row"><code><span class="memberNameLink"><a href="#explainTerms(org.apache.calcite.rel.RelWriter)">explainTerms</a></span>&#8203;(<a href="RelWriter.html" title="interface in org.apache.calcite.rel">RelWriter</a>&nbsp;pw)</code></th>
 <td class="colLast">
 <div class="block">Describes the inputs and attributes of this relational expression.</div>
 </td>
 </tr>
 <tr id="i14" class="altColor">
 <td class="colFirst"><code>java.util.List&lt;<a href="../rex/RexNode.html" title="class in org.apache.calcite.rex">RexNode</a>&gt;</code></td>
 <th class="colSecond" scope="row"><code><span class="memberNameLink"><a href="#getChildExps()">getChildExps</a></span>()</code></th>
 <td class="colLast">
 <div class="block">Returns a list of this relational expression's child expressions.</div>
 </td>
 </tr>
 <tr id="i15" class="rowColor">
 <td class="colFirst"><code><a href="../plan/RelOptCluster.html" title="class in org.apache.calcite.plan">RelOptCluster</a></code></td>
 <th class="colSecond" scope="row"><code><span class="memberNameLink"><a href="#getCluster()">getCluster</a></span>()</code></th>
 <td class="colLast">
 <div class="block">Returns the cluster this relational expression belongs to.</div>
 </td>
 </tr>
 <tr id="i16" class="altColor">
 <td class="colFirst"><code>java.util.List&lt;<a href="RelCollation.html" title="interface in org.apache.calcite.rel">RelCollation</a>&gt;</code></td>
 <th class="colSecond" scope="row"><code><span class="memberNameLink"><a href="#getCollationList()">getCollationList</a></span>()</code></th>
 <td class="colLast">
 <div class="block"><span class="deprecatedLabel">Deprecated.</span>
 <div class="deprecationComment">Use <a href="metadata/RelMetadataQuery.html#collations(org.apache.calcite.rel.RelNode)"><code>RelMetadataQuery.collations(RelNode)</code></a></div>
 </div>
 </td>
 </tr>
 <tr id="i17" class="rowColor">
 <td class="colFirst"><code><a href="../plan/Convention.html" title="interface in org.apache.calcite.plan">Convention</a></code></td>
 <th class="colSecond" scope="row"><code><span class="memberNameLink"><a href="#getConvention()">getConvention</a></span>()</code></th>
 <td class="colLast">
 <div class="block">Return the CallingConvention trait from this RelNode's
  <a href="../plan/RelOptNode.html#getTraitSet()"><code>trait set</code></a>.</div>
 </td>
 </tr>
 <tr id="i18" class="altColor">
 <td class="colFirst"><code>java.lang.String</code></td>
 <th class="colSecond" scope="row"><code><span class="memberNameLink"><a href="#getCorrelVariable()">getCorrelVariable</a></span>()</code></th>
 <td class="colLast">
 <div class="block">Returns the name of the variable which is to be implicitly set at runtime
  each time a row is returned from the first input of this relational
  expression; or null if there is no variable.</div>
 </td>
 </tr>
 <tr id="i19" class="rowColor">
 <td class="colFirst"><code>java.lang.String</code></td>
 <th class="colSecond" scope="row"><code><span class="memberNameLink"><a href="#getDescription()">getDescription</a></span>()</code></th>
 <td class="colLast">
 <div class="block">Returns a string which describes the relational expression and, unlike
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 </td>
 </tr>
 <tr id="i20" class="altColor">
 <td class="colFirst"><code>java.lang.String</code></td>
 <th class="colSecond" scope="row"><code><span class="memberNameLink"><a href="#getDigest()">getDigest</a></span>()</code></th>
 <td class="colLast">
 <div class="block">Returns a string which concisely describes the definition of this
  relational expression.</div>
 </td>
 </tr>
 <tr id="i21" class="rowColor">
 <td class="colFirst"><code><a href="type/RelDataType.html" title="interface in org.apache.calcite.rel.type">RelDataType</a></code></td>
 <th class="colSecond" scope="row"><code><span class="memberNameLink"><a href="#getExpectedInputRowType(int)">getExpectedInputRowType</a></span>&#8203;(int&nbsp;ordinalInParent)</code></th>
 <td class="colLast">
 <div class="block">Returns the type of the rows expected for an input.</div>
 </td>
 </tr>
 <tr id="i22" class="altColor">
 <td class="colFirst"><code>int</code></td>
 <th class="colSecond" scope="row"><code><span class="memberNameLink"><a href="#getId()">getId</a></span>()</code></th>
 <td class="colLast">
 <div class="block">Returns the ID of this relational expression, unique among all relational
  expressions created since the server was started.</div>
 </td>
 </tr>
 <tr id="i23" class="rowColor">
 <td class="colFirst"><code><a href="RelNode.html" title="interface in org.apache.calcite.rel">RelNode</a></code></td>
 <th class="colSecond" scope="row"><code><span class="memberNameLink"><a href="#getInput(int)">getInput</a></span>&#8203;(int&nbsp;i)</code></th>
 <td class="colLast">
 <div class="block">Returns the <code>i</code><sup>th</sup> input relational expression.</div>
 </td>
 </tr>
 <tr id="i24" class="altColor">
 <td class="colFirst"><code>java.util.List&lt;<a href="RelNode.html" title="interface in org.apache.calcite.rel">RelNode</a>&gt;</code></td>
 <th class="colSecond" scope="row"><code><span class="memberNameLink"><a href="#getInputs()">getInputs</a></span>()</code></th>
 <td class="colLast">
 <div class="block">Returns an array of this relational expression's inputs.</div>
 </td>
 </tr>
 <tr id="i25" class="rowColor">
 <td class="colFirst"><code><a href="../plan/RelOptQuery.html" title="class in org.apache.calcite.plan">RelOptQuery</a></code></td>
 <th class="colSecond" scope="row"><code><span class="memberNameLink"><a href="#getQuery()">getQuery</a></span>()</code></th>
 <td class="colLast">
 <div class="block">Returns the sub-query this relational expression belongs to.</div>
 </td>
 </tr>
 <tr id="i26" class="altColor">
 <td class="colFirst"><code>java.lang.String</code></td>
 <th class="colSecond" scope="row"><code><span class="memberNameLink"><a href="#getRelTypeName()">getRelTypeName</a></span>()</code></th>
 <td class="colLast">
 <div class="block">Returns the name of this relational expression's class, sans package
  name, for use in explain.</div>
 </td>
 </tr>
 <tr id="i27" class="rowColor">
 <td class="colFirst"><code>double</code></td>
 <th class="colSecond" scope="row"><code><span class="memberNameLink"><a href="#getRows()">getRows</a></span>()</code></th>
 <td class="colLast">&nbsp;</td>
 </tr>
 <tr id="i28" class="altColor">
 <td class="colFirst"><code><a href="type/RelDataType.html" title="interface in org.apache.calcite.rel.type">RelDataType</a></code></td>
 <th class="colSecond" scope="row"><code><span class="memberNameLink"><a href="#getRowType()">getRowType</a></span>()</code></th>
 <td class="colLast">
 <div class="block">Returns the type of the rows returned by this relational expression.</div>
 </td>
 </tr>
 <tr id="i29" class="rowColor">
 <td class="colFirst"><code><a href="../plan/RelOptTable.html" title="interface in org.apache.calcite.plan">RelOptTable</a></code></td>
 <th class="colSecond" scope="row"><code><span class="memberNameLink"><a href="#getTable()">getTable</a></span>()</code></th>
 <td class="colLast">
 <div class="block">If this relational expression represents an access to a table, returns
  that table, otherwise returns null.</div>
 </td>
 </tr>
 <tr id="i30" class="altColor">
 <td class="colFirst"><code><a href="../plan/RelTraitSet.html" title="class in org.apache.calcite.plan">RelTraitSet</a></code></td>
 <th class="colSecond" scope="row"><code><span class="memberNameLink"><a href="#getTraitSet()">getTraitSet</a></span>()</code></th>
 <td class="colLast">
 <div class="block">Retrieves this RelNode's traits.</div>
 </td>
 </tr>
 <tr id="i31" class="rowColor">
 <td class="colFirst"><code>java.util.Set&lt;<a href="core/CorrelationId.html" title="class in org.apache.calcite.rel.core">CorrelationId</a>&gt;</code></td>
 <th class="colSecond" scope="row"><code><span class="memberNameLink"><a href="#getVariablesSet()">getVariablesSet</a></span>()</code></th>
 <td class="colLast">
 <div class="block">Returns the variables that are set in this relational
  expression but also used and therefore not available to parents of this
  relational expression.</div>
 </td>
 </tr>
 <tr id="i32" class="altColor">
 <td class="colFirst"><code>java.util.Set&lt;java.lang.String&gt;</code></td>
 <th class="colSecond" scope="row"><code><span class="memberNameLink"><a href="#getVariablesStopped()">getVariablesStopped</a></span>()</code></th>
 <td class="colLast">
 <div class="block">Returns the names of variables that are set in this relational
  expression but also used and therefore not available to parents of this
  relational expression.</div>
 </td>
 </tr>
 <tr id="i33" class="rowColor">
 <td class="colFirst"><code>int</code></td>
 <th class="colSecond" scope="row"><code><span class="memberNameLink"><a href="#hashCode()">hashCode</a></span>()</code></th>
 </tr>
 <tr id="i34" class="altColor">
 <td class="colFirst"><code>boolean</code></td>
 <th class="colSecond" scope="row"><code><span class="memberNameLink"><a href="#isDistinct()">isDistinct</a></span>()</code></th>
 <td class="colLast">
 <div class="block">Returns whether the same value will not come out twice.</div>
 </td>
 </tr>
 <tr id="i35" class="rowColor">
 <td class="colFirst"><code>boolean</code></td>
 <th class="colSecond" scope="row"><code><span class="memberNameLink"><a href="#isKey(org.apache.calcite.util.ImmutableBitSet)">isKey</a></span>&#8203;(<a href="../util/ImmutableBitSet.html" title="class in org.apache.calcite.util">ImmutableBitSet</a>&nbsp;columns)</code></th>
 <td class="colLast">
 <div class="block">Returns whether the result of this relational expression is uniquely
  identified by this columns with the given ordinals.</div>
 </td>
 </tr>
 <tr id="i36" class="altColor">
 <td class="colFirst"><code>boolean</code></td>
 <th class="colSecond" scope="row"><code><span class="memberNameLink"><a href="#isValid(boolean)">isValid</a></span>&#8203;(boolean&nbsp;fail)</code></th>
 <td class="colLast">&nbsp;</td>
 </tr>
 <tr id="i37" class="rowColor">
 <td class="colFirst"><code>boolean</code></td>
 <th class="colSecond" scope="row"><code><span class="memberNameLink"><a href="#isValid(org.apache.calcite.util.Litmus,org.apache.calcite.rel.RelNode.Context)">isValid</a></span>&#8203;(<a href="../util/Litmus.html" title="interface in org.apache.calcite.util">Litmus</a>&nbsp;litmus,
        <a href="RelNode.Context.html" title="interface in org.apache.calcite.rel">RelNode.Context</a>&nbsp;context)</code></th>
 <td class="colLast">
 <div class="block">Returns whether this relational expression is valid.</div>
 </td>
 </tr>
 <tr id="i38" class="altColor">
 <td class="colFirst"><code>&lt;M extends <a href="metadata/Metadata.html" title="interface in org.apache.calcite.rel.metadata">Metadata</a>&gt;<br>M</code></td>
 <th class="colSecond" scope="row"><code><span class="memberNameLink"><a href="#metadata(java.lang.Class,org.apache.calcite.rel.metadata.RelMetadataQuery)">metadata</a></span>&#8203;(java.lang.Class&lt;M&gt;&nbsp;metadataClass,
         <a href="metadata/RelMetadataQuery.html" title="class in org.apache.calcite.rel.metadata">RelMetadataQuery</a>&nbsp;mq)</code></th>
 <td class="colLast">
 <div class="block">Returns a metadata interface.</div>
 </td>
 </tr>
 <tr id="i39" class="rowColor">
 <td class="colFirst"><code><a href="RelNode.html" title="interface in org.apache.calcite.rel">RelNode</a></code></td>
 <th class="colSecond" scope="row"><code><span class="memberNameLink"><a href="#onRegister(org.apache.calcite.plan.RelOptPlanner)">onRegister</a></span>&#8203;(<a href="../plan/RelOptPlanner.html" title="interface in org.apache.calcite.plan">RelOptPlanner</a>&nbsp;planner)</code></th>
 <td class="colLast">
 <div class="block">Receives notification that this expression is about to be registered.</div>
 </td>
 </tr>
 <tr id="i40" class="altColor">
 <td class="colFirst"><code>java.lang.String</code></td>
 <th class="colSecond" scope="row"><code><span class="memberNameLink"><a href="#recomputeDigest()">recomputeDigest</a></span>()</code></th>
 <td class="colLast">
 <div class="block">Computes the digest, assigns it, and returns it.</div>
 </td>
 </tr>
 <tr id="i41" class="rowColor">
 <td class="colFirst"><code>void</code></td>
 <th class="colSecond" scope="row"><code><span class="memberNameLink"><a href="#register(org.apache.calcite.plan.RelOptPlanner)">register</a></span>&#8203;(<a href="../plan/RelOptPlanner.html" title="interface in org.apache.calcite.plan">RelOptPlanner</a>&nbsp;planner)</code></th>
 <td class="colLast">
 <div class="block">Registers any special rules specific to this kind of relational
  expression.</div>
 </td>
 </tr>
 <tr id="i42" class="altColor">
 <td class="colFirst"><code>void</code></td>
 <th class="colSecond" scope="row"><code><span class="memberNameLink"><a href="#replaceInput(int,org.apache.calcite.rel.RelNode)">replaceInput</a></span>&#8203;(int&nbsp;ordinalInParent,
             <a href="RelNode.html" title="interface in org.apache.calcite.rel">RelNode</a>&nbsp;p)</code></th>
 <td class="colLast">
 <div class="block">Replaces the <code>ordinalInParent</code><sup>th</sup> input.</div>
 </td>
 </tr>
 <tr id="i43" class="rowColor">
 <td class="colFirst"><code>protected static &lt;T&gt;&nbsp;T</code></td>
 <th class="colSecond" scope="row"><code><span class="memberNameLink"><a href="#sole(java.util.List)">sole</a></span>&#8203;(java.util.List&lt;T&gt;&nbsp;collection)</code></th>
 <td class="colLast">&nbsp;</td>
 </tr>
 <tr id="i44" class="altColor">
 <td class="colFirst"><code>java.lang.String</code></td>
 <th class="colSecond" scope="row"><code><span class="memberNameLink"><a href="#toString()">toString</a></span>()</code></th>
 <td class="colLast">&nbsp;</td>
 </tr>
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 <h3>Methods inherited from class&nbsp;java.lang.Object</h3>
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 <pre>private static final&nbsp;java.util.concurrent.atomic.AtomicInteger NEXT_ID</pre>
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 <pre>private static final&nbsp;org.slf4j.Logger LOGGER</pre>
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 <h4>desc</h4>
 <pre>private&nbsp;java.lang.String desc</pre>
 <div class="block">Description, consists of id plus digest.</div>
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 <pre>protected&nbsp;<a href="type/RelDataType.html" title="interface in org.apache.calcite.rel.type">RelDataType</a> rowType</pre>
 <div class="block">Cached type of this relational expression.</div>
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 <h4>digest</h4>
 <pre>protected&nbsp;java.lang.String digest</pre>
 <div class="block">A short description of this relational expression's type, inputs, and
  other properties. The string uniquely identifies the node; another node
  is equivalent if and only if it has the same value. Computed by
  <a href="#computeDigest()"><code>computeDigest()</code></a>, assigned by <a href="#onRegister(org.apache.calcite.plan.RelOptPlanner)"><code>onRegister(org.apache.calcite.plan.RelOptPlanner)</code></a>, returned by
  <a href="#getDigest()"><code>getDigest()</code></a>.</div>
 <dl>
 <dt><span class="seeLabel">See Also:</span></dt>
 <dd><a href="#desc"><code>desc</code></a></dd>
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 </li>
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 <h4>cluster</h4>
 <pre>private final&nbsp;<a href="../plan/RelOptCluster.html" title="class in org.apache.calcite.plan">RelOptCluster</a> cluster</pre>
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 <pre>protected final&nbsp;int id</pre>
 <div class="block">unique id of this object -- for debugging</div>
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 <h4>traitSet</h4>
 <pre>protected&nbsp;<a href="../plan/RelTraitSet.html" title="class in org.apache.calcite.plan">RelTraitSet</a> traitSet</pre>
 <div class="block">The RelTraitSet that describes the traits of this RelNode.</div>
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 <h3>Constructor Detail</h3>
 <a id="&lt;init&gt;(org.apache.calcite.plan.RelOptCluster,org.apache.calcite.plan.RelTraitSet)">
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 <h4>AbstractRelNode</h4>
 <pre>public&nbsp;AbstractRelNode&#8203;(<a href="../plan/RelOptCluster.html" title="class in org.apache.calcite.plan">RelOptCluster</a>&nbsp;cluster,
                        <a href="../plan/RelTraitSet.html" title="class in org.apache.calcite.plan">RelTraitSet</a>&nbsp;traitSet)</pre>
 <div class="block">Creates an <code>AbstractRelNode</code>.</div>
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 <!-- ============ METHOD DETAIL ========== -->
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 <a id="copy(org.apache.calcite.plan.RelTraitSet,java.util.List)">
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 <h4>copy</h4>
 <pre class="methodSignature">public&nbsp;<a href="RelNode.html" title="interface in org.apache.calcite.rel">RelNode</a>&nbsp;copy&#8203;(<a href="../plan/RelTraitSet.html" title="class in org.apache.calcite.plan">RelTraitSet</a>&nbsp;traitSet,
                     java.util.List&lt;<a href="RelNode.html" title="interface in org.apache.calcite.rel">RelNode</a>&gt;&nbsp;inputs)</pre>
 <div class="block"><span class="descfrmTypeLabel">Description copied from interface:&nbsp;<code><a href="RelNode.html#copy(org.apache.calcite.plan.RelTraitSet,java.util.List)">RelNode</a></code></span></div>
 <div class="block">Creates a copy of this relational expression, perhaps changing traits and
  inputs.

  <p>Sub-classes with other important attributes are encouraged to create
  variants of this method with more parameters.</p></div>
 <dl>
 <dt><span class="overrideSpecifyLabel">Specified by:</span></dt>
 <dd><code><a href="RelNode.html#copy(org.apache.calcite.plan.RelTraitSet,java.util.List)">copy</a></code>&nbsp;in interface&nbsp;<code><a href="RelNode.html" title="interface in org.apache.calcite.rel">RelNode</a></code></dd>
 <dt><span class="paramLabel">Parameters:</span></dt>
 <dd><code>traitSet</code> - Trait set</dd>
 <dd><code>inputs</code> - Inputs</dd>
 <dt><span class="returnLabel">Returns:</span></dt>
 <dd>Copy of this relational expression, substituting traits and
  inputs</dd>
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 <pre class="methodSignature">protected static&nbsp;&lt;T&gt;&nbsp;T&nbsp;sole&#8203;(java.util.List&lt;T&gt;&nbsp;collection)</pre>
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 <h4>getChildExps</h4>
 <pre class="methodSignature">public&nbsp;java.util.List&lt;<a href="../rex/RexNode.html" title="class in org.apache.calcite.rex">RexNode</a>&gt;&nbsp;getChildExps()</pre>
 <div class="block"><span class="descfrmTypeLabel">Description copied from interface:&nbsp;<code><a href="RelNode.html#getChildExps()">RelNode</a></code></span></div>
 <div class="block">Returns a list of this relational expression's child expressions.
  (These are scalar expressions, and so do not include the relational
  inputs that are returned by <a href="RelNode.html#getInputs()"><code>RelNode.getInputs()</code></a>.

  <p>The caller should treat the list as unmodifiable; typical
  implementations will return an immutable list. If there are no
  child expressions, returns an empty list, not <code>null</code>.</div>
 <dl>
 <dt><span class="overrideSpecifyLabel">Specified by:</span></dt>
 <dd><code><a href="RelNode.html#getChildExps()">getChildExps</a></code>&nbsp;in interface&nbsp;<code><a href="RelNode.html" title="interface in org.apache.calcite.rel">RelNode</a></code></dd>
 <dt><span class="returnLabel">Returns:</span></dt>
 <dd>List of this relational expression's child expressions</dd>
 <dt><span class="seeLabel">See Also:</span></dt>
 <dd><a href="RelNode.html#accept(org.apache.calcite.rex.RexShuttle)"><code>RelNode.accept(org.apache.calcite.rex.RexShuttle)</code></a></dd>
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 <h4>getCluster</h4>
 <pre class="methodSignature">public final&nbsp;<a href="../plan/RelOptCluster.html" title="class in org.apache.calcite.plan">RelOptCluster</a>&nbsp;getCluster()</pre>
 <div class="block"><span class="descfrmTypeLabel">Description copied from interface:&nbsp;<code><a href="../plan/RelOptNode.html#getCluster()">RelOptNode</a></code></span></div>
 <div class="block">Returns the cluster this relational expression belongs to.</div>
 <dl>
 <dt><span class="overrideSpecifyLabel">Specified by:</span></dt>
 <dd><code><a href="../plan/RelOptNode.html#getCluster()">getCluster</a></code>&nbsp;in interface&nbsp;<code><a href="../plan/RelOptNode.html" title="interface in org.apache.calcite.plan">RelOptNode</a></code></dd>
 <dt><span class="returnLabel">Returns:</span></dt>
 <dd>cluster</dd>
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 <h4>getConvention</h4>
 <pre class="methodSignature">public final&nbsp;<a href="../plan/Convention.html" title="interface in org.apache.calcite.plan">Convention</a>&nbsp;getConvention()</pre>
 <div class="block"><span class="descfrmTypeLabel">Description copied from interface:&nbsp;<code><a href="RelNode.html#getConvention()">RelNode</a></code></span></div>
 <div class="block">Return the CallingConvention trait from this RelNode's
  <a href="../plan/RelOptNode.html#getTraitSet()"><code>trait set</code></a>.</div>
 <dl>
 <dt><span class="overrideSpecifyLabel">Specified by:</span></dt>
 <dd><code><a href="RelNode.html#getConvention()">getConvention</a></code>&nbsp;in interface&nbsp;<code><a href="RelNode.html" title="interface in org.apache.calcite.rel">RelNode</a></code></dd>
 <dt><span class="returnLabel">Returns:</span></dt>
 <dd>this RelNode's CallingConvention</dd>
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 <pre class="methodSignature">public&nbsp;<a href="../plan/RelTraitSet.html" title="class in org.apache.calcite.plan">RelTraitSet</a>&nbsp;getTraitSet()</pre>
 <div class="block"><span class="descfrmTypeLabel">Description copied from interface:&nbsp;<code><a href="../plan/RelOptNode.html#getTraitSet()">RelOptNode</a></code></span></div>
 <div class="block">Retrieves this RelNode's traits. Note that although the RelTraitSet
  returned is modifiable, it <b>must not</b> be modified during
  optimization. It is legal to modify the traits of a RelNode before or
  after optimization, although doing so could render a tree of RelNodes
  unimplementable. If a RelNode's traits need to be modified during
  optimization, clone the RelNode and change the clone's traits.</div>
 <dl>
 <dt><span class="overrideSpecifyLabel">Specified by:</span></dt>
 <dd><code><a href="../plan/RelOptNode.html#getTraitSet()">getTraitSet</a></code>&nbsp;in interface&nbsp;<code><a href="../plan/RelOptNode.html" title="interface in org.apache.calcite.plan">RelOptNode</a></code></dd>
 <dt><span class="returnLabel">Returns:</span></dt>
 <dd>this RelNode's trait set</dd>
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 <a id="getCorrelVariable()">
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 <h4>getCorrelVariable</h4>
 <pre class="methodSignature">public&nbsp;java.lang.String&nbsp;getCorrelVariable()</pre>
 <div class="block"><span class="descfrmTypeLabel">Description copied from interface:&nbsp;<code><a href="RelNode.html#getCorrelVariable()">RelNode</a></code></span></div>
 <div class="block">Returns the name of the variable which is to be implicitly set at runtime
  each time a row is returned from the first input of this relational
  expression; or null if there is no variable.</div>
 <dl>
 <dt><span class="overrideSpecifyLabel">Specified by:</span></dt>
 <dd><code><a href="RelNode.html#getCorrelVariable()">getCorrelVariable</a></code>&nbsp;in interface&nbsp;<code><a href="RelNode.html" title="interface in org.apache.calcite.rel">RelNode</a></code></dd>
 <dt><span class="returnLabel">Returns:</span></dt>
 <dd>Name of correlating variable, or null</dd>
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 <h4>isDistinct</h4>
 <pre class="methodSignature">public&nbsp;boolean&nbsp;isDistinct()</pre>
 <div class="block"><span class="descfrmTypeLabel">Description copied from interface:&nbsp;<code><a href="RelNode.html#isDistinct()">RelNode</a></code></span></div>
 <div class="block">Returns whether the same value will not come out twice. Default value is
  <code>false</code>, derived classes should override.</div>
 <dl>
 <dt><span class="overrideSpecifyLabel">Specified by:</span></dt>
 <dd><code><a href="RelNode.html#isDistinct()">isDistinct</a></code>&nbsp;in interface&nbsp;<code><a href="RelNode.html" title="interface in org.apache.calcite.rel">RelNode</a></code></dd>
 <dt><span class="returnLabel">Returns:</span></dt>
 <dd>Whether the same value will not come out twice</dd>
 </dl>
 </li>
 </ul>
 <a id="isKey(org.apache.calcite.util.ImmutableBitSet)">
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 </a>
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 <h4>isKey</h4>
 <pre class="methodSignature">public&nbsp;boolean&nbsp;isKey&#8203;(<a href="../util/ImmutableBitSet.html" title="class in org.apache.calcite.util">ImmutableBitSet</a>&nbsp;columns)</pre>
 <div class="block"><span class="descfrmTypeLabel">Description copied from interface:&nbsp;<code><a href="RelNode.html#isKey(org.apache.calcite.util.ImmutableBitSet)">RelNode</a></code></span></div>
 <div class="block">Returns whether the result of this relational expression is uniquely
  identified by this columns with the given ordinals.

  <p>For example, if this relational expression is a LogicalTableScan to
  T(A, B, C, D) whose key is (A, B), then isKey([0, 1]) yields true,
  and isKey([0]) and isKey([0, 2]) yields false.</p></div>
 <dl>
 <dt><span class="overrideSpecifyLabel">Specified by:</span></dt>
 <dd><code><a href="RelNode.html#isKey(org.apache.calcite.util.ImmutableBitSet)">isKey</a></code>&nbsp;in interface&nbsp;<code><a href="RelNode.html" title="interface in org.apache.calcite.rel">RelNode</a></code></dd>
 <dt><span class="paramLabel">Parameters:</span></dt>
 <dd><code>columns</code> - Ordinals of key columns</dd>
 <dt><span class="returnLabel">Returns:</span></dt>
 <dd>Whether the given columns are a key or a superset of a key</dd>
 </dl>
 </li>
 </ul>
 <a id="getId()">
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 <h4>getId</h4>
 <pre class="methodSignature">public&nbsp;int&nbsp;getId()</pre>
 <div class="block"><span class="descfrmTypeLabel">Description copied from interface:&nbsp;<code><a href="../plan/RelOptNode.html#getId()">RelOptNode</a></code></span></div>
 <div class="block">Returns the ID of this relational expression, unique among all relational
  expressions created since the server was started.</div>
 <dl>
 <dt><span class="overrideSpecifyLabel">Specified by:</span></dt>
 <dd><code><a href="../plan/RelOptNode.html#getId()">getId</a></code>&nbsp;in interface&nbsp;<code><a href="../plan/RelOptNode.html" title="interface in org.apache.calcite.plan">RelOptNode</a></code></dd>
 <dt><span class="returnLabel">Returns:</span></dt>
 <dd>Unique ID</dd>
 </dl>
 </li>
 </ul>
 <a id="getInput(int)">
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 <h4>getInput</h4>
 <pre class="methodSignature">public&nbsp;<a href="RelNode.html" title="interface in org.apache.calcite.rel">RelNode</a>&nbsp;getInput&#8203;(int&nbsp;i)</pre>
 <div class="block"><span class="descfrmTypeLabel">Description copied from interface:&nbsp;<code><a href="RelNode.html#getInput(int)">RelNode</a></code></span></div>
 <div class="block">Returns the <code>i</code><sup>th</sup> input relational expression.</div>
 <dl>
 <dt><span class="overrideSpecifyLabel">Specified by:</span></dt>
 <dd><code><a href="RelNode.html#getInput(int)">getInput</a></code>&nbsp;in interface&nbsp;<code><a href="RelNode.html" title="interface in org.apache.calcite.rel">RelNode</a></code></dd>
 <dt><span class="paramLabel">Parameters:</span></dt>
 <dd><code>i</code> - Ordinal of input</dd>
 <dt><span class="returnLabel">Returns:</span></dt>
 <dd><code>i</code><sup>th</sup> input</dd>
 </dl>
 </li>
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 <a id="getQuery()">
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 <ul class="blockList">
 <li class="blockList">
 <h4>getQuery</h4>
 <pre class="methodSignature">public final&nbsp;<a href="../plan/RelOptQuery.html" title="class in org.apache.calcite.plan">RelOptQuery</a>&nbsp;getQuery()</pre>
 <div class="block"><span class="descfrmTypeLabel">Description copied from interface:&nbsp;<code><a href="RelNode.html#getQuery()">RelNode</a></code></span></div>
 <div class="block">Returns the sub-query this relational expression belongs to.</div>
 <dl>
 <dt><span class="overrideSpecifyLabel">Specified by:</span></dt>
 <dd><code><a href="RelNode.html#getQuery()">getQuery</a></code>&nbsp;in interface&nbsp;<code><a href="RelNode.html" title="interface in org.apache.calcite.rel">RelNode</a></code></dd>
 <dt><span class="returnLabel">Returns:</span></dt>
 <dd>Sub-query</dd>
 </dl>
 </li>
 </ul>
 <a id="register(org.apache.calcite.plan.RelOptPlanner)">
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 <h4>register</h4>
 <pre class="methodSignature">public&nbsp;void&nbsp;register&#8203;(<a href="../plan/RelOptPlanner.html" title="interface in org.apache.calcite.plan">RelOptPlanner</a>&nbsp;planner)</pre>
 <div class="block"><span class="descfrmTypeLabel">Description copied from interface:&nbsp;<code><a href="RelNode.html#register(org.apache.calcite.plan.RelOptPlanner)">RelNode</a></code></span></div>
 <div class="block">Registers any special rules specific to this kind of relational
  expression.

  <p>The planner calls this method this first time that it sees a
  relational expression of this class. The derived class should call
  <a href="../plan/RelOptPlanner.html#addRule(org.apache.calcite.plan.RelOptRule)"><code>RelOptPlanner.addRule(org.apache.calcite.plan.RelOptRule)</code></a> for each rule, and
  then call <code>super.register</code>.</p></div>
 <dl>
 <dt><span class="overrideSpecifyLabel">Specified by:</span></dt>
 <dd><code><a href="RelNode.html#register(org.apache.calcite.plan.RelOptPlanner)">register</a></code>&nbsp;in interface&nbsp;<code><a href="RelNode.html" title="interface in org.apache.calcite.rel">RelNode</a></code></dd>
 <dt><span class="paramLabel">Parameters:</span></dt>
 <dd><code>planner</code> - Planner to be used to register additional relational
                 expressions</dd>
 </dl>
 </li>
 </ul>
 <a id="getRelTypeName()">
 <!--   -->
 </a>
 <ul class="blockList">
 <li class="blockList">
 <h4>getRelTypeName</h4>
 <pre class="methodSignature">public final&nbsp;java.lang.String&nbsp;getRelTypeName()</pre>
 <div class="block"><span class="descfrmTypeLabel">Description copied from interface:&nbsp;<code><a href="RelNode.html#getRelTypeName()">RelNode</a></code></span></div>
 <div class="block">Returns the name of this relational expression's class, sans package
  name, for use in explain. For example, for a <code>
  org.apache.calcite.rel.ArrayRel.ArrayReader</code>, this method returns
  "ArrayReader".</div>
 <dl>
 <dt><span class="overrideSpecifyLabel">Specified by:</span></dt>
 <dd><code><a href="RelNode.html#getRelTypeName()">getRelTypeName</a></code>&nbsp;in interface&nbsp;<code><a href="RelNode.html" title="interface in org.apache.calcite.rel">RelNode</a></code></dd>
 <dt><span class="returnLabel">Returns:</span></dt>
 <dd>Name of this relational expression's class, sans package name,
    for use in explain</dd>
 </dl>
 </li>
 </ul>
 <a id="isValid(org.apache.calcite.util.Litmus,org.apache.calcite.rel.RelNode.Context)">
 <!--   -->
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 <h4>isValid</h4>
 <pre class="methodSignature">public&nbsp;boolean&nbsp;isValid&#8203;(<a href="../util/Litmus.html" title="interface in org.apache.calcite.util">Litmus</a>&nbsp;litmus,
                        <a href="RelNode.Context.html" title="interface in org.apache.calcite.rel">RelNode.Context</a>&nbsp;context)</pre>
 <div class="block"><span class="descfrmTypeLabel">Description copied from interface:&nbsp;<code><a href="RelNode.html#isValid(org.apache.calcite.util.Litmus,org.apache.calcite.rel.RelNode.Context)">RelNode</a></code></span></div>
 <div class="block">Returns whether this relational expression is valid.

  <p>If assertions are enabled, this method is typically called with <code>
  litmus</code> = <code>THROW</code>, as follows:

  <blockquote>
  <pre>assert rel.isValid(Litmus.THROW)</pre>
  </blockquote>

  <p>This signals that the method can throw an <code>AssertionError</code> if it
  is not valid.</div>
 <dl>
 <dt><span class="overrideSpecifyLabel">Specified by:</span></dt>
 <dd><code><a href="RelNode.html#isValid(org.apache.calcite.util.Litmus,org.apache.calcite.rel.RelNode.Context)">isValid</a></code>&nbsp;in interface&nbsp;<code><a href="RelNode.html" title="interface in org.apache.calcite.rel">RelNode</a></code></dd>
 <dt><span class="paramLabel">Parameters:</span></dt>
 <dd><code>litmus</code> - What to do if invalid</dd>
 <dd><code>context</code> - Context for validity checking</dd>
 <dt><span class="returnLabel">Returns:</span></dt>
 <dd>Whether relational expression is valid</dd>
 </dl>
 </li>
 </ul>
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 <h4>isValid</h4>
 <pre class="methodSignature">public&nbsp;boolean&nbsp;isValid&#8203;(boolean&nbsp;fail)</pre>
 <dl>
 <dt><span class="overrideSpecifyLabel">Specified by:</span></dt>
 <dd><code><a href="RelNode.html#isValid(boolean)">isValid</a></code>&nbsp;in interface&nbsp;<code><a href="RelNode.html" title="interface in org.apache.calcite.rel">RelNode</a></code></dd>
 </dl>
 </li>
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 <a id="getCollationList()">
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 <li class="blockList">
 <h4>getCollationList</h4>
 <pre class="methodSignature">@Deprecated
 public&nbsp;java.util.List&lt;<a href="RelCollation.html" title="interface in org.apache.calcite.rel">RelCollation</a>&gt;&nbsp;getCollationList()</pre>
 <div class="deprecationBlock"><span class="deprecatedLabel">Deprecated.</span>
 <div class="deprecationComment">Use <a href="metadata/RelMetadataQuery.html#collations(org.apache.calcite.rel.RelNode)"><code>RelMetadataQuery.collations(RelNode)</code></a></div>
 </div>
 <div class="block"><span class="descfrmTypeLabel">Description copied from interface:&nbsp;<code><a href="RelNode.html#getCollationList()">RelNode</a></code></span></div>
 <div class="block">Returns a description of the physical ordering (or orderings) of this
  relational expression. Never null.</div>
 <dl>
 <dt><span class="overrideSpecifyLabel">Specified by:</span></dt>
 <dd><code><a href="RelNode.html#getCollationList()">getCollationList</a></code>&nbsp;in interface&nbsp;<code><a href="RelNode.html" title="interface in org.apache.calcite.rel">RelNode</a></code></dd>
 <dt><span class="returnLabel">Returns:</span></dt>
 <dd>Description of the physical ordering (or orderings) of this
    relational expression. Never null</dd>
 </dl>
 </li>
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 <a id="getRowType()">
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 <h4>getRowType</h4>
 <pre class="methodSignature">public final&nbsp;<a href="type/RelDataType.html" title="interface in org.apache.calcite.rel.type">RelDataType</a>&nbsp;getRowType()</pre>
 <div class="block"><span class="descfrmTypeLabel">Description copied from interface:&nbsp;<code><a href="RelNode.html#getRowType()">RelNode</a></code></span></div>
 <div class="block">Returns the type of the rows returned by this relational expression.</div>
 <dl>
 <dt><span class="overrideSpecifyLabel">Specified by:</span></dt>
 <dd><code><a href="RelNode.html#getRowType()">getRowType</a></code>&nbsp;in interface&nbsp;<code><a href="RelNode.html" title="interface in org.apache.calcite.rel">RelNode</a></code></dd>
 <dt><span class="overrideSpecifyLabel">Specified by:</span></dt>
 <dd><code><a href="../plan/RelOptNode.html#getRowType()">getRowType</a></code>&nbsp;in interface&nbsp;<code><a href="../plan/RelOptNode.html" title="interface in org.apache.calcite.plan">RelOptNode</a></code></dd>
 </dl>
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 <h4>deriveRowType</h4>
 <pre class="methodSignature">protected&nbsp;<a href="type/RelDataType.html" title="interface in org.apache.calcite.rel.type">RelDataType</a>&nbsp;deriveRowType()</pre>
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 <li class="blockList">
 <h4>getExpectedInputRowType</h4>
 <pre class="methodSignature">public&nbsp;<a href="type/RelDataType.html" title="interface in org.apache.calcite.rel.type">RelDataType</a>&nbsp;getExpectedInputRowType&#8203;(int&nbsp;ordinalInParent)</pre>
 <div class="block"><span class="descfrmTypeLabel">Description copied from interface:&nbsp;<code><a href="RelNode.html#getExpectedInputRowType(int)">RelNode</a></code></span></div>
 <div class="block">Returns the type of the rows expected for an input. Defaults to
  <a href="RelNode.html#getRowType()"><code>RelNode.getRowType()</code></a>.</div>
 <dl>
 <dt><span class="overrideSpecifyLabel">Specified by:</span></dt>
 <dd><code><a href="RelNode.html#getExpectedInputRowType(int)">getExpectedInputRowType</a></code>&nbsp;in interface&nbsp;<code><a href="RelNode.html" title="interface in org.apache.calcite.rel">RelNode</a></code></dd>
 <dt><span class="paramLabel">Parameters:</span></dt>
 <dd><code>ordinalInParent</code> - input's 0-based ordinal with respect to this
                         parent rel</dd>
 <dt><span class="returnLabel">Returns:</span></dt>
 <dd>expected row type</dd>
 </dl>
 </li>
 </ul>
 <a id="getInputs()">
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 </a>
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 <li class="blockList">
 <h4>getInputs</h4>
 <pre class="methodSignature">public&nbsp;java.util.List&lt;<a href="RelNode.html" title="interface in org.apache.calcite.rel">RelNode</a>&gt;&nbsp;getInputs()</pre>
 <div class="block"><span class="descfrmTypeLabel">Description copied from interface:&nbsp;<code><a href="RelNode.html#getInputs()">RelNode</a></code></span></div>
 <div class="block">Returns an array of this relational expression's inputs. If there are no
  inputs, returns an empty list, not <code>null</code>.</div>
 <dl>
 <dt><span class="overrideSpecifyLabel">Specified by:</span></dt>
 <dd><code><a href="RelNode.html#getInputs()">getInputs</a></code>&nbsp;in interface&nbsp;<code><a href="RelNode.html" title="interface in org.apache.calcite.rel">RelNode</a></code></dd>
 <dt><span class="overrideSpecifyLabel">Specified by:</span></dt>
 <dd><code><a href="../plan/RelOptNode.html#getInputs()">getInputs</a></code>&nbsp;in interface&nbsp;<code><a href="../plan/RelOptNode.html" title="interface in org.apache.calcite.plan">RelOptNode</a></code></dd>
 <dt><span class="returnLabel">Returns:</span></dt>
 <dd>Array of this relational expression's inputs</dd>
 </dl>
 </li>
 </ul>
 <a id="getRows()">
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 <h4>getRows</h4>
 <pre class="methodSignature">public final&nbsp;double&nbsp;getRows()</pre>
 <dl>
 <dt><span class="overrideSpecifyLabel">Specified by:</span></dt>
 <dd><code><a href="RelNode.html#getRows()">getRows</a></code>&nbsp;in interface&nbsp;<code><a href="RelNode.html" title="interface in org.apache.calcite.rel">RelNode</a></code></dd>
 </dl>
 </li>
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 <a id="estimateRowCount(org.apache.calcite.rel.metadata.RelMetadataQuery)">
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 <ul class="blockList">
 <li class="blockList">
 <h4>estimateRowCount</h4>
 <pre class="methodSignature">public&nbsp;double&nbsp;estimateRowCount&#8203;(<a href="metadata/RelMetadataQuery.html" title="class in org.apache.calcite.rel.metadata">RelMetadataQuery</a>&nbsp;mq)</pre>
 <div class="block"><span class="descfrmTypeLabel">Description copied from interface:&nbsp;<code><a href="RelNode.html#estimateRowCount(org.apache.calcite.rel.metadata.RelMetadataQuery)">RelNode</a></code></span></div>
 <div class="block">Returns an estimate of the number of rows this relational expression will
  return.

  <p>NOTE jvs 29-Mar-2006: Don't call this method directly. Instead, use
  <a href="metadata/RelMetadataQuery.html#getRowCount(org.apache.calcite.rel.RelNode)"><code>RelMetadataQuery.getRowCount(org.apache.calcite.rel.RelNode)</code></a>, which gives plugins a chance to
  override the rel's default ideas about row count.</div>
 <dl>
 <dt><span class="overrideSpecifyLabel">Specified by:</span></dt>
 <dd><code><a href="RelNode.html#estimateRowCount(org.apache.calcite.rel.metadata.RelMetadataQuery)">estimateRowCount</a></code>&nbsp;in interface&nbsp;<code><a href="RelNode.html" title="interface in org.apache.calcite.rel">RelNode</a></code></dd>
 <dt><span class="paramLabel">Parameters:</span></dt>
 <dd><code>mq</code> - Metadata query</dd>
 <dt><span class="returnLabel">Returns:</span></dt>
 <dd>Estimate of the number of rows this relational expression will
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 <a id="getVariablesStopped()">
 <!--   -->
 </a>
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 <li class="blockList">
 <h4>getVariablesStopped</h4>
 <pre class="methodSignature">public final&nbsp;java.util.Set&lt;java.lang.String&gt;&nbsp;getVariablesStopped()</pre>
 <div class="block"><span class="descfrmTypeLabel">Description copied from interface:&nbsp;<code><a href="RelNode.html#getVariablesStopped()">RelNode</a></code></span></div>
 <div class="block">Returns the names of variables that are set in this relational
  expression but also used and therefore not available to parents of this
  relational expression.

  <p>Note: only <a href="core/Correlate.html" title="class in org.apache.calcite.rel.core"><code>Correlate</code></a> should set
  variables.

  <p>Note: <a href="RelNode.html#getVariablesSet()"><code>RelNode.getVariablesSet()</code></a> is equivalent but returns
  <a href="core/CorrelationId.html" title="class in org.apache.calcite.rel.core"><code>CorrelationId</code></a> rather than their names. It is preferable except for
  calling old methods that require a set of strings.</div>
 <dl>
 <dt><span class="overrideSpecifyLabel">Specified by:</span></dt>
 <dd><code><a href="RelNode.html#getVariablesStopped()">getVariablesStopped</a></code>&nbsp;in interface&nbsp;<code><a href="RelNode.html" title="interface in org.apache.calcite.rel">RelNode</a></code></dd>
 <dt><span class="returnLabel">Returns:</span></dt>
 <dd>Names of variables which are set in this relational
    expression</dd>
 </dl>
 </li>
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 <a id="getVariablesSet()">
 <!--   -->
 </a>
 <ul class="blockList">
 <li class="blockList">
 <h4>getVariablesSet</h4>
 <pre class="methodSignature">public&nbsp;java.util.Set&lt;<a href="core/CorrelationId.html" title="class in org.apache.calcite.rel.core">CorrelationId</a>&gt;&nbsp;getVariablesSet()</pre>
 <div class="block"><span class="descfrmTypeLabel">Description copied from interface:&nbsp;<code><a href="RelNode.html#getVariablesSet()">RelNode</a></code></span></div>
 <div class="block">Returns the variables that are set in this relational
  expression but also used and therefore not available to parents of this
  relational expression.

  <p>Note: only <a href="core/Correlate.html" title="class in org.apache.calcite.rel.core"><code>Correlate</code></a> should set
  variables.</div>
 <dl>
 <dt><span class="overrideSpecifyLabel">Specified by:</span></dt>
 <dd><code><a href="RelNode.html#getVariablesSet()">getVariablesSet</a></code>&nbsp;in interface&nbsp;<code><a href="RelNode.html" title="interface in org.apache.calcite.rel">RelNode</a></code></dd>
 <dt><span class="returnLabel">Returns:</span></dt>
 <dd>Names of variables which are set in this relational
    expression</dd>
 </dl>
 </li>
 </ul>
 <a id="collectVariablesUsed(java.util.Set)">
 <!--   -->
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 <ul class="blockList">
 <li class="blockList">
 <h4>collectVariablesUsed</h4>
 <pre class="methodSignature">public&nbsp;void&nbsp;collectVariablesUsed&#8203;(java.util.Set&lt;<a href="core/CorrelationId.html" title="class in org.apache.calcite.rel.core">CorrelationId</a>&gt;&nbsp;variableSet)</pre>
 <div class="block"><span class="descfrmTypeLabel">Description copied from interface:&nbsp;<code><a href="RelNode.html#collectVariablesUsed(java.util.Set)">RelNode</a></code></span></div>
 <div class="block">Collects variables known to be used by this expression or its
  descendants. By default, no such information is available and must be
  derived by analyzing sub-expressions, but some optimizer implementations
  may insert special expressions which remember such information.</div>
 <dl>
 <dt><span class="overrideSpecifyLabel">Specified by:</span></dt>
 <dd><code><a href="RelNode.html#collectVariablesUsed(java.util.Set)">collectVariablesUsed</a></code>&nbsp;in interface&nbsp;<code><a href="RelNode.html" title="interface in org.apache.calcite.rel">RelNode</a></code></dd>
 <dt><span class="paramLabel">Parameters:</span></dt>
 <dd><code>variableSet</code> - receives variables used</dd>
 </dl>
 </li>
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 <a id="collectVariablesSet(java.util.Set)">
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 <h4>collectVariablesSet</h4>
 <pre class="methodSignature">public&nbsp;void&nbsp;collectVariablesSet&#8203;(java.util.Set&lt;<a href="core/CorrelationId.html" title="class in org.apache.calcite.rel.core">CorrelationId</a>&gt;&nbsp;variableSet)</pre>
 <div class="block"><span class="descfrmTypeLabel">Description copied from interface:&nbsp;<code><a href="RelNode.html#collectVariablesSet(java.util.Set)">RelNode</a></code></span></div>
 <div class="block">Collects variables set by this expression.
  TODO: is this required?</div>
 <dl>
 <dt><span class="overrideSpecifyLabel">Specified by:</span></dt>
 <dd><code><a href="RelNode.html#collectVariablesSet(java.util.Set)">collectVariablesSet</a></code>&nbsp;in interface&nbsp;<code><a href="RelNode.html" title="interface in org.apache.calcite.rel">RelNode</a></code></dd>
 <dt><span class="paramLabel">Parameters:</span></dt>
 <dd><code>variableSet</code> - receives variables known to be set by</dd>
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 <a id="childrenAccept(org.apache.calcite.rel.RelVisitor)">
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 <h4>childrenAccept</h4>
 <pre class="methodSignature">public&nbsp;void&nbsp;childrenAccept&#8203;(<a href="RelVisitor.html" title="class in org.apache.calcite.rel">RelVisitor</a>&nbsp;visitor)</pre>
 <div class="block"><span class="descfrmTypeLabel">Description copied from interface:&nbsp;<code><a href="RelNode.html#childrenAccept(org.apache.calcite.rel.RelVisitor)">RelNode</a></code></span></div>
 <div class="block">Interacts with the <a href="RelVisitor.html" title="class in org.apache.calcite.rel"><code>RelVisitor</code></a> in a
  <a href="../util/Glossary.html#VISITOR_PATTERN"><code>visitor pattern</code></a> to
  traverse the tree of relational expressions.</div>
 <dl>
 <dt><span class="overrideSpecifyLabel">Specified by:</span></dt>
 <dd><code><a href="RelNode.html#childrenAccept(org.apache.calcite.rel.RelVisitor)">childrenAccept</a></code>&nbsp;in interface&nbsp;<code><a href="RelNode.html" title="interface in org.apache.calcite.rel">RelNode</a></code></dd>
 <dt><span class="paramLabel">Parameters:</span></dt>
 <dd><code>visitor</code> - Visitor that will traverse the tree of relational
                 expressions</dd>
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 <a id="accept(org.apache.calcite.rel.RelShuttle)">
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 <h4>accept</h4>
 <pre class="methodSignature">public&nbsp;<a href="RelNode.html" title="interface in org.apache.calcite.rel">RelNode</a>&nbsp;accept&#8203;(<a href="RelShuttle.html" title="interface in org.apache.calcite.rel">RelShuttle</a>&nbsp;shuttle)</pre>
 <div class="block"><span class="descfrmTypeLabel">Description copied from interface:&nbsp;<code><a href="RelNode.html#accept(org.apache.calcite.rel.RelShuttle)">RelNode</a></code></span></div>
 <div class="block">Accepts a visit from a shuttle.</div>
 <dl>
 <dt><span class="overrideSpecifyLabel">Specified by:</span></dt>
 <dd><code><a href="RelNode.html#accept(org.apache.calcite.rel.RelShuttle)">accept</a></code>&nbsp;in interface&nbsp;<code><a href="RelNode.html" title="interface in org.apache.calcite.rel">RelNode</a></code></dd>
 <dt><span class="paramLabel">Parameters:</span></dt>
 <dd><code>shuttle</code> - Shuttle</dd>
 <dt><span class="returnLabel">Returns:</span></dt>
 <dd>A copy of this node incorporating changes made by the shuttle to
  this node's children</dd>
 </dl>
 </li>
 </ul>
 <a id="accept(org.apache.calcite.rex.RexShuttle)">
 <!--   -->
 </a>
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 <h4>accept</h4>
 <pre class="methodSignature">public&nbsp;<a href="RelNode.html" title="interface in org.apache.calcite.rel">RelNode</a>&nbsp;accept&#8203;(<a href="../rex/RexShuttle.html" title="class in org.apache.calcite.rex">RexShuttle</a>&nbsp;shuttle)</pre>
 <div class="block"><span class="descfrmTypeLabel">Description copied from interface:&nbsp;<code><a href="RelNode.html#accept(org.apache.calcite.rex.RexShuttle)">RelNode</a></code></span></div>
 <div class="block">Accepts a visit from a shuttle. If the shuttle updates expression, then
  a copy of the relation should be created. This new relation might have
  a different row-type.</div>
 <dl>
 <dt><span class="overrideSpecifyLabel">Specified by:</span></dt>
 <dd><code><a href="RelNode.html#accept(org.apache.calcite.rex.RexShuttle)">accept</a></code>&nbsp;in interface&nbsp;<code><a href="RelNode.html" title="interface in org.apache.calcite.rel">RelNode</a></code></dd>
 <dt><span class="paramLabel">Parameters:</span></dt>
 <dd><code>shuttle</code> - Shuttle</dd>
 <dt><span class="returnLabel">Returns:</span></dt>
 <dd>A copy of this node incorporating changes made by the shuttle to
  this node's children</dd>
 </dl>
 </li>
 </ul>
 <a id="computeSelfCost(org.apache.calcite.plan.RelOptPlanner)">
 <!--   -->
 </a>
 <ul class="blockList">
 <li class="blockList">
 <h4>computeSelfCost</h4>
 <pre class="methodSignature">public final&nbsp;<a href="../plan/RelOptCost.html" title="interface in org.apache.calcite.plan">RelOptCost</a>&nbsp;computeSelfCost&#8203;(<a href="../plan/RelOptPlanner.html" title="interface in org.apache.calcite.plan">RelOptPlanner</a>&nbsp;planner)</pre>
 <dl>
 <dt><span class="overrideSpecifyLabel">Specified by:</span></dt>
 <dd><code><a href="RelNode.html#computeSelfCost(org.apache.calcite.plan.RelOptPlanner)">computeSelfCost</a></code>&nbsp;in interface&nbsp;<code><a href="RelNode.html" title="interface in org.apache.calcite.rel">RelNode</a></code></dd>
 </dl>
 </li>
 </ul>
 <a id="computeSelfCost(org.apache.calcite.plan.RelOptPlanner,org.apache.calcite.rel.metadata.RelMetadataQuery)">
 <!--   -->
 </a>
 <ul class="blockList">
 <li class="blockList">
 <h4>computeSelfCost</h4>
 <pre class="methodSignature">public&nbsp;<a href="../plan/RelOptCost.html" title="interface in org.apache.calcite.plan">RelOptCost</a>&nbsp;computeSelfCost&#8203;(<a href="../plan/RelOptPlanner.html" title="interface in org.apache.calcite.plan">RelOptPlanner</a>&nbsp;planner,
                                   <a href="metadata/RelMetadataQuery.html" title="class in org.apache.calcite.rel.metadata">RelMetadataQuery</a>&nbsp;mq)</pre>
 <div class="block"><span class="descfrmTypeLabel">Description copied from interface:&nbsp;<code><a href="RelNode.html#computeSelfCost(org.apache.calcite.plan.RelOptPlanner,org.apache.calcite.rel.metadata.RelMetadataQuery)">RelNode</a></code></span></div>
 <div class="block">Returns the cost of this plan (not including children). The base
  implementation throws an error; derived classes should override.

  <p>NOTE jvs 29-Mar-2006: Don't call this method directly. Instead, use
  <a href="metadata/RelMetadataQuery.html#getNonCumulativeCost(org.apache.calcite.rel.RelNode)"><code>RelMetadataQuery.getNonCumulativeCost(org.apache.calcite.rel.RelNode)</code></a>, which gives plugins a
  chance to override the rel's default ideas about cost.</div>
 <dl>
 <dt><span class="overrideSpecifyLabel">Specified by:</span></dt>
 <dd><code><a href="RelNode.html#computeSelfCost(org.apache.calcite.plan.RelOptPlanner,org.apache.calcite.rel.metadata.RelMetadataQuery)">computeSelfCost</a></code>&nbsp;in interface&nbsp;<code><a href="RelNode.html" title="interface in org.apache.calcite.rel">RelNode</a></code></dd>
 <dt><span class="paramLabel">Parameters:</span></dt>
 <dd><code>planner</code> - Planner for cost calculation</dd>
 <dd><code>mq</code> - Metadata query</dd>
 <dt><span class="returnLabel">Returns:</span></dt>
 <dd>Cost of this plan (not including children)</dd>
 </dl>
 </li>
 </ul>
 <a id="metadata(java.lang.Class,org.apache.calcite.rel.metadata.RelMetadataQuery)">
 <!--   -->
 </a>
 <ul class="blockList">
 <li class="blockList">
 <h4>metadata</h4>
 <pre class="methodSignature">public final&nbsp;&lt;M extends <a href="metadata/Metadata.html" title="interface in org.apache.calcite.rel.metadata">Metadata</a>&gt;&nbsp;M&nbsp;metadata&#8203;(java.lang.Class&lt;M&gt;&nbsp;metadataClass,
                                              <a href="metadata/RelMetadataQuery.html" title="class in org.apache.calcite.rel.metadata">RelMetadataQuery</a>&nbsp;mq)</pre>
 <div class="block"><span class="descfrmTypeLabel">Description copied from interface:&nbsp;<code><a href="RelNode.html#metadata(java.lang.Class,org.apache.calcite.rel.metadata.RelMetadataQuery)">RelNode</a></code></span></div>
 <div class="block">Returns a metadata interface.</div>
 <dl>
 <dt><span class="overrideSpecifyLabel">Specified by:</span></dt>
 <dd><code><a href="RelNode.html#metadata(java.lang.Class,org.apache.calcite.rel.metadata.RelMetadataQuery)">metadata</a></code>&nbsp;in interface&nbsp;<code><a href="RelNode.html" title="interface in org.apache.calcite.rel">RelNode</a></code></dd>
 <dt><span class="paramLabel">Type Parameters:</span></dt>
 <dd><code>M</code> - Type of metadata being requested</dd>
 <dt><span class="paramLabel">Parameters:</span></dt>
 <dd><code>metadataClass</code> - Metadata interface</dd>
 <dd><code>mq</code> - Metadata query</dd>
 <dt><span class="returnLabel">Returns:</span></dt>
 <dd>Metadata object that supplies the desired metadata (never null,
      although if the information is not present the metadata object may
      return null from all methods)</dd>
 </dl>
 </li>
 </ul>
 <a id="explain(org.apache.calcite.rel.RelWriter)">
 <!--   -->
 </a>
 <ul class="blockList">
 <li class="blockList">
 <h4>explain</h4>
 <pre class="methodSignature">public&nbsp;void&nbsp;explain&#8203;(<a href="RelWriter.html" title="interface in org.apache.calcite.rel">RelWriter</a>&nbsp;pw)</pre>
 <div class="block"><span class="descfrmTypeLabel">Description copied from interface:&nbsp;<code><a href="RelNode.html#explain(org.apache.calcite.rel.RelWriter)">RelNode</a></code></span></div>
 <div class="block">Describes the inputs and attributes of this relational expression.
  Each node should call <code>super.explain</code>, then call the
  <a href="RelWriter.html#input(java.lang.String,org.apache.calcite.rel.RelNode)"><code>RelWriter.input(String, RelNode)</code></a>
  and
  <a href="externalize/RelWriterImpl.html#item(java.lang.String,java.lang.Object)"><code>RelWriterImpl.item(String, Object)</code></a>
  methods for each input and attribute.</div>
 <dl>
 <dt><span class="overrideSpecifyLabel">Specified by:</span></dt>
 <dd><code><a href="RelNode.html#explain(org.apache.calcite.rel.RelWriter)">explain</a></code>&nbsp;in interface&nbsp;<code><a href="RelNode.html" title="interface in org.apache.calcite.rel">RelNode</a></code></dd>
 <dt><span class="paramLabel">Parameters:</span></dt>
 <dd><code>pw</code> - Plan writer</dd>
 </dl>
 </li>
 </ul>
 <a id="explainTerms(org.apache.calcite.rel.RelWriter)">
 <!--   -->
 </a>
 <ul class="blockList">
 <li class="blockList">
 <h4>explainTerms</h4>
 <pre class="methodSignature">public&nbsp;<a href="RelWriter.html" title="interface in org.apache.calcite.rel">RelWriter</a>&nbsp;explainTerms&#8203;(<a href="RelWriter.html" title="interface in org.apache.calcite.rel">RelWriter</a>&nbsp;pw)</pre>
 <div class="block">Describes the inputs and attributes of this relational expression.
  Each node should call <code>super.explainTerms</code>, then call the
  <a href="RelWriter.html#input(java.lang.String,org.apache.calcite.rel.RelNode)"><code>RelWriter.input(String, RelNode)</code></a>
  and
  <a href="externalize/RelWriterImpl.html#item(java.lang.String,java.lang.Object)"><code>RelWriterImpl.item(String, Object)</code></a>
  methods for each input and attribute.</div>
 <dl>
 <dt><span class="paramLabel">Parameters:</span></dt>
 <dd><code>pw</code> - Plan writer</dd>
 <dt><span class="returnLabel">Returns:</span></dt>
 <dd>Plan writer for fluent-explain pattern</dd>
 </dl>
 </li>
 </ul>
 <a id="onRegister(org.apache.calcite.plan.RelOptPlanner)">
 <!--   -->
 </a>
 <ul class="blockList">
 <li class="blockList">
 <h4>onRegister</h4>
 <pre class="methodSignature">public&nbsp;<a href="RelNode.html" title="interface in org.apache.calcite.rel">RelNode</a>&nbsp;onRegister&#8203;(<a href="../plan/RelOptPlanner.html" title="interface in org.apache.calcite.plan">RelOptPlanner</a>&nbsp;planner)</pre>
 <div class="block"><span class="descfrmTypeLabel">Description copied from interface:&nbsp;<code><a href="RelNode.html#onRegister(org.apache.calcite.plan.RelOptPlanner)">RelNode</a></code></span></div>
 <div class="block">Receives notification that this expression is about to be registered. The
  implementation of this method must at least register all child
  expressions.</div>
 <dl>
 <dt><span class="overrideSpecifyLabel">Specified by:</span></dt>
 <dd><code><a href="RelNode.html#onRegister(org.apache.calcite.plan.RelOptPlanner)">onRegister</a></code>&nbsp;in interface&nbsp;<code><a href="RelNode.html" title="interface in org.apache.calcite.rel">RelNode</a></code></dd>
 <dt><span class="paramLabel">Parameters:</span></dt>
 <dd><code>planner</code> - Planner that plans this relational node</dd>
 <dt><span class="returnLabel">Returns:</span></dt>
 <dd>Relational expression that should be used by the planner</dd>
 </dl>
 </li>
 </ul>
 <a id="recomputeDigest()">
 <!--   -->
 </a>
 <ul class="blockList">
 <li class="blockList">
 <h4>recomputeDigest</h4>
 <pre class="methodSignature">public&nbsp;java.lang.String&nbsp;recomputeDigest()</pre>
 <div class="block"><span class="descfrmTypeLabel">Description copied from interface:&nbsp;<code><a href="RelNode.html#recomputeDigest()">RelNode</a></code></span></div>
 <div class="block">Computes the digest, assigns it, and returns it. For planner use only.</div>
 <dl>
 <dt><span class="overrideSpecifyLabel">Specified by:</span></dt>
 <dd><code><a href="RelNode.html#recomputeDigest()">recomputeDigest</a></code>&nbsp;in interface&nbsp;<code><a href="RelNode.html" title="interface in org.apache.calcite.rel">RelNode</a></code></dd>
 <dt><span class="returnLabel">Returns:</span></dt>
 <dd>Digest of this relational expression</dd>
 </dl>
 </li>
 </ul>
 <a id="replaceInput(int,org.apache.calcite.rel.RelNode)">
 <!--   -->
 </a>
 <ul class="blockList">
 <li class="blockList">
 <h4>replaceInput</h4>
 <pre class="methodSignature">public&nbsp;void&nbsp;replaceInput&#8203;(int&nbsp;ordinalInParent,
                          <a href="RelNode.html" title="interface in org.apache.calcite.rel">RelNode</a>&nbsp;p)</pre>
 <div class="block"><span class="descfrmTypeLabel">Description copied from interface:&nbsp;<code><a href="RelNode.html#replaceInput(int,org.apache.calcite.rel.RelNode)">RelNode</a></code></span></div>
 <div class="block">Replaces the <code>ordinalInParent</code><sup>th</sup> input. You must
  override this method if you override <a href="RelNode.html#getInputs()"><code>RelNode.getInputs()</code></a>.</div>
 <dl>
 <dt><span class="overrideSpecifyLabel">Specified by:</span></dt>
 <dd><code><a href="RelNode.html#replaceInput(int,org.apache.calcite.rel.RelNode)">replaceInput</a></code>&nbsp;in interface&nbsp;<code><a href="RelNode.html" title="interface in org.apache.calcite.rel">RelNode</a></code></dd>
 <dt><span class="paramLabel">Parameters:</span></dt>
 <dd><code>ordinalInParent</code> - Position of the child input, 0 is the first</dd>
 <dd><code>p</code> - New node that should be put at position <code>ordinalInParent</code></dd>
 </dl>
 </li>
 </ul>
 <a id="toString()">
 <!--   -->
 </a>
 <ul class="blockList">
 <li class="blockList">
 <h4>toString</h4>
 <pre class="methodSignature">public&nbsp;java.lang.String&nbsp;toString()</pre>
 <dl>
 <dt><span class="overrideSpecifyLabel">Overrides:</span></dt>
 <dd><code>toString</code>&nbsp;in class&nbsp;<code>java.lang.Object</code></dd>
 </dl>
 </li>
 </ul>
 <a id="getDescription()">
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 <h4>getDescription</h4>
 <pre class="methodSignature">public final&nbsp;java.lang.String&nbsp;getDescription()</pre>
 <div class="block"><span class="descfrmTypeLabel">Description copied from interface:&nbsp;<code><a href="../plan/RelOptNode.html#getDescription()">RelOptNode</a></code></span></div>
 <div class="block">Returns a string which describes the relational expression and, unlike
  <a href="../plan/RelOptNode.html#getDigest()"><code>RelOptNode.getDigest()</code></a>, also includes the identity. Typically returns
  "rel#{id}:{digest}".</div>
 <dl>
 <dt><span class="overrideSpecifyLabel">Specified by:</span></dt>
 <dd><code><a href="../plan/RelOptNode.html#getDescription()">getDescription</a></code>&nbsp;in interface&nbsp;<code><a href="../plan/RelOptNode.html" title="interface in org.apache.calcite.plan">RelOptNode</a></code></dd>
 <dt><span class="returnLabel">Returns:</span></dt>
 <dd>String which describes the relational expression and, unlike
    <a href="../plan/RelOptNode.html#getDigest()"><code>RelOptNode.getDigest()</code></a>, also includes the identity</dd>
 </dl>
 </li>
 </ul>
 <a id="getDigest()">
 <!--   -->
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 <li class="blockList">
 <h4>getDigest</h4>
 <pre class="methodSignature">public final&nbsp;java.lang.String&nbsp;getDigest()</pre>
 <div class="block"><span class="descfrmTypeLabel">Description copied from interface:&nbsp;<code><a href="../plan/RelOptNode.html#getDigest()">RelOptNode</a></code></span></div>
 <div class="block">Returns a string which concisely describes the definition of this
  relational expression. Two relational expressions are equivalent if
  their digests and <a href="../plan/RelOptNode.html#getRowType()"><code>RelOptNode.getRowType()</code></a> are the same.

  <p>The digest does not contain the relational expression's identity --
  that would prevent similar relational expressions from ever comparing
  equal -- but does include the identity of children (on the assumption
  that children have already been normalized).

  <p>If you want a descriptive string which contains the identity, call
  <code>Object.toString()</code>, which always returns "rel#{id}:{digest}".</div>
 <dl>
 <dt><span class="overrideSpecifyLabel">Specified by:</span></dt>
 <dd><code><a href="../plan/RelOptNode.html#getDigest()">getDigest</a></code>&nbsp;in interface&nbsp;<code><a href="../plan/RelOptNode.html" title="interface in org.apache.calcite.plan">RelOptNode</a></code></dd>
 <dt><span class="returnLabel">Returns:</span></dt>
 <dd>Digest of this <code>RelNode</code></dd>
 </dl>
 </li>
 </ul>
 <a id="getTable()">
 <!--   -->
 </a>
 <ul class="blockList">
 <li class="blockList">
 <h4>getTable</h4>
 <pre class="methodSignature">public&nbsp;<a href="../plan/RelOptTable.html" title="interface in org.apache.calcite.plan">RelOptTable</a>&nbsp;getTable()</pre>
 <div class="block"><span class="descfrmTypeLabel">Description copied from interface:&nbsp;<code><a href="RelNode.html#getTable()">RelNode</a></code></span></div>
 <div class="block">If this relational expression represents an access to a table, returns
  that table, otherwise returns null.</div>
 <dl>
 <dt><span class="overrideSpecifyLabel">Specified by:</span></dt>
 <dd><code><a href="RelNode.html#getTable()">getTable</a></code>&nbsp;in interface&nbsp;<code><a href="RelNode.html" title="interface in org.apache.calcite.rel">RelNode</a></code></dd>
 <dt><span class="returnLabel">Returns:</span></dt>
 <dd>If this relational expression represents an access to a table,
    returns that table, otherwise returns null</dd>
 </dl>
 </li>
 </ul>
 <a id="computeDigest()">
 <!--   -->
 </a>
 <ul class="blockList">
 <li class="blockList">
 <h4>computeDigest</h4>
 <pre class="methodSignature">protected&nbsp;java.lang.String&nbsp;computeDigest()</pre>
 <div class="block">Computes the digest. Does not modify this object.</div>
 <dl>
 <dt><span class="returnLabel">Returns:</span></dt>
 <dd>Digest</dd>
 </dl>
 </li>
 </ul>
 <a id="equals(java.lang.Object)">
 <!--   -->
 </a>
 <ul class="blockList">
 <li class="blockList">
 <h4>equals</h4>
 <pre class="methodSignature">public final&nbsp;boolean&nbsp;equals&#8203;(java.lang.Object&nbsp;obj)</pre>
 <div class="block">

  <p>This method (and <a href="#hashCode()"><code>hashCode()</code></a> is intentionally final. We do not want
  sub-classes of <a href="RelNode.html" title="interface in org.apache.calcite.rel"><code>RelNode</code></a> to redefine identity. Various algorithms
  (e.g. visitors, planner) can define the identity as meets their needs.</div>
 <dl>
 <dt><span class="overrideSpecifyLabel">Overrides:</span></dt>
 <dd><code>equals</code>&nbsp;in class&nbsp;<code>java.lang.Object</code></dd>
 </dl>
 </li>
 </ul>
 <a id="hashCode()">
 <!--   -->
 </a>
 <ul class="blockListLast">
 <li class="blockList">
 <h4>hashCode</h4>
 <pre class="methodSignature">public final&nbsp;int&nbsp;hashCode()</pre>
 <div class="block">

  <p>This method (and <a href="#equals(java.lang.Object)"><code>equals(java.lang.Object)</code></a> is intentionally final. We do not want
  sub-classes of <a href="RelNode.html" title="interface in org.apache.calcite.rel"><code>RelNode</code></a> to redefine identity. Various algorithms
  (e.g. visitors, planner) can define the identity as meets their needs.</div>
 <dl>
 <dt><span class="overrideSpecifyLabel">Overrides:</span></dt>
 <dd><code>hashCode</code>&nbsp;in class&nbsp;<code>java.lang.Object</code></dd>
 </dl>
 </li>
 </ul>
 </li>
 </ul>
 </section>
 </li>
 </ul>
 </div>
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