import{_ as t,r as p,o as c,c as o,a as l,d as n,e as s,b as i,w as u,f as a}from"./app-R9uoKBuv.js";const r={},d=a(`<h1 id="java-native-api" tabindex="-1"><a class="header-anchor" href="#java-native-api" aria-hidden="true">#</a> Java Native API</h1><h2 id="installation" tabindex="-1"><a class="header-anchor" href="#installation" aria-hidden="true">#</a> Installation</h2><h3 id="dependencies" tabindex="-1"><a class="header-anchor" href="#dependencies" aria-hidden="true">#</a> Dependencies</h3><ul><li>JDK &gt;= 1.8</li><li>Maven &gt;= 3.6</li></ul><h3 id="how-to-install" tabindex="-1"><a class="header-anchor" href="#how-to-install" aria-hidden="true">#</a> How to install</h3><p>In root directory:</p><blockquote><p>mvn clean install -pl iotdb-client/session -am -DskipTests</p></blockquote><h3 id="using-iotdb-java-native-api-with-maven" tabindex="-1"><a class="header-anchor" href="#using-iotdb-java-native-api-with-maven" aria-hidden="true">#</a> Using IoTDB Java Native API with Maven</h3><div class="language-xml line-numbers-mode" data-ext="xml"><pre class="language-xml"><code><span class="token tag"><span class="token tag"><span class="token punctuation">&lt;</span>dependencies</span><span class="token punctuation">&gt;</span></span>
    <span class="token tag"><span class="token tag"><span class="token punctuation">&lt;</span>dependency</span><span class="token punctuation">&gt;</span></span>
      <span class="token tag"><span class="token tag"><span class="token punctuation">&lt;</span>groupId</span><span class="token punctuation">&gt;</span></span>org.apache.iotdb<span class="token tag"><span class="token tag"><span class="token punctuation">&lt;/</span>groupId</span><span class="token punctuation">&gt;</span></span>
      <span class="token tag"><span class="token tag"><span class="token punctuation">&lt;</span>artifactId</span><span class="token punctuation">&gt;</span></span>iotdb-session<span class="token tag"><span class="token tag"><span class="token punctuation">&lt;/</span>artifactId</span><span class="token punctuation">&gt;</span></span>
      <span class="token tag"><span class="token tag"><span class="token punctuation">&lt;</span>version</span><span class="token punctuation">&gt;</span></span>1.0.0<span class="token tag"><span class="token tag"><span class="token punctuation">&lt;/</span>version</span><span class="token punctuation">&gt;</span></span>
    <span class="token tag"><span class="token tag"><span class="token punctuation">&lt;/</span>dependency</span><span class="token punctuation">&gt;</span></span>
<span class="token tag"><span class="token tag"><span class="token punctuation">&lt;/</span>dependencies</span><span class="token punctuation">&gt;</span></span>
</code></pre><div class="line-numbers" aria-hidden="true"><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div></div></div><h2 id="syntax-convention" tabindex="-1"><a class="header-anchor" href="#syntax-convention" aria-hidden="true">#</a> Syntax Convention</h2>`,10),k=n("strong",null,"IoTDB-SQL interface:",-1),m=n("li",null,[n("strong",null,"Other interfaces:"),n("ul",null,[n("li",null,"The node names in path or path prefix as parameter: The node names which should be escaped by backticks (`) in the SQL statement, escaping is required here."),n("li",null,"Identifiers (such as template names) as parameters: The identifiers which should be escaped by backticks (`) in the SQL statement, and escaping is not required here.")])],-1),v=n("li",null,[n("strong",null,"Code example for syntax convention could be found at:"),s(),n("code",null,"example/session/src/main/java/org/apache/iotdb/SyntaxConventionRelatedExample.java")],-1),g=a(`<h2 id="native-apis" tabindex="-1"><a class="header-anchor" href="#native-apis" aria-hidden="true">#</a> Native APIs</h2><p>Here we show the commonly used interfaces and their parameters in the Native API:</p><h3 id="initialization" tabindex="-1"><a class="header-anchor" href="#initialization" aria-hidden="true">#</a> Initialization</h3><ul><li>Initialize a Session</li></ul><div class="language-java line-numbers-mode" data-ext="java"><pre class="language-java"><code><span class="token comment">// use default configuration </span>
session <span class="token operator">=</span> <span class="token keyword">new</span> <span class="token class-name">Session<span class="token punctuation">.</span>Builder</span><span class="token punctuation">.</span><span class="token function">build</span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token punctuation">;</span>

<span class="token comment">// initialize with a single node</span>
session <span class="token operator">=</span> 
    <span class="token keyword">new</span> <span class="token class-name">Session<span class="token punctuation">.</span>Builder</span><span class="token punctuation">(</span><span class="token punctuation">)</span>
        <span class="token punctuation">.</span><span class="token function">host</span><span class="token punctuation">(</span><span class="token class-name">String</span> host<span class="token punctuation">)</span>
        <span class="token punctuation">.</span><span class="token function">port</span><span class="token punctuation">(</span><span class="token keyword">int</span> port<span class="token punctuation">)</span>
        <span class="token punctuation">.</span><span class="token function">build</span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token punctuation">;</span>

<span class="token comment">// initialize with multiple nodes</span>
session <span class="token operator">=</span> 
    <span class="token keyword">new</span> <span class="token class-name">Session<span class="token punctuation">.</span>Builder</span><span class="token punctuation">(</span><span class="token punctuation">)</span>
        <span class="token punctuation">.</span><span class="token function">nodeUrls</span><span class="token punctuation">(</span><span class="token class-name">List</span><span class="token generics"><span class="token punctuation">&lt;</span><span class="token class-name">String</span><span class="token punctuation">&gt;</span></span> nodeUrls<span class="token punctuation">)</span>
        <span class="token punctuation">.</span><span class="token function">build</span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token punctuation">;</span>

<span class="token comment">// other configurations</span>
session <span class="token operator">=</span> 
    <span class="token keyword">new</span> <span class="token class-name">Session<span class="token punctuation">.</span>Builder</span><span class="token punctuation">(</span><span class="token punctuation">)</span>
        <span class="token punctuation">.</span><span class="token function">fetchSize</span><span class="token punctuation">(</span><span class="token keyword">int</span> fetchSize<span class="token punctuation">)</span>
        <span class="token punctuation">.</span><span class="token function">username</span><span class="token punctuation">(</span><span class="token class-name">String</span> username<span class="token punctuation">)</span>
        <span class="token punctuation">.</span><span class="token function">password</span><span class="token punctuation">(</span><span class="token class-name">String</span> password<span class="token punctuation">)</span>
        <span class="token punctuation">.</span><span class="token function">thriftDefaultBufferSize</span><span class="token punctuation">(</span><span class="token keyword">int</span> thriftDefaultBufferSize<span class="token punctuation">)</span>
        <span class="token punctuation">.</span><span class="token function">thriftMaxFrameSize</span><span class="token punctuation">(</span><span class="token keyword">int</span> thriftMaxFrameSize<span class="token punctuation">)</span>
        <span class="token punctuation">.</span><span class="token function">enableRedirection</span><span class="token punctuation">(</span><span class="token keyword">boolean</span> enableRedirection<span class="token punctuation">)</span>
        <span class="token punctuation">.</span><span class="token function">version</span><span class="token punctuation">(</span><span class="token class-name">Version</span> version<span class="token punctuation">)</span>
        <span class="token punctuation">.</span><span class="token function">build</span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token punctuation">;</span>
</code></pre><div class="line-numbers" aria-hidden="true"><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div></div></div><p>Version represents the SQL semantic version used by the client, which is used to be compatible with the SQL semantics of 0.12 when upgrading 0.13. The possible values are: <code>V_0_12</code>, <code>V_0_13</code>, <code>V_1_0</code>.</p><ul><li>Open a Session</li></ul><div class="language-java line-numbers-mode" data-ext="java"><pre class="language-java"><code><span class="token keyword">void</span> <span class="token keyword">open</span><span class="token punctuation">(</span><span class="token punctuation">)</span>
</code></pre><div class="line-numbers" aria-hidden="true"><div class="line-number"></div></div></div><ul><li>Open a session, with a parameter to specify whether to enable RPC compression</li></ul><div class="language-java line-numbers-mode" data-ext="java"><pre class="language-java"><code><span class="token keyword">void</span> <span class="token keyword">open</span><span class="token punctuation">(</span><span class="token keyword">boolean</span> enableRPCCompression<span class="token punctuation">)</span>
</code></pre><div class="line-numbers" aria-hidden="true"><div class="line-number"></div></div></div><p>Notice: this RPC compression status of client must comply with that of IoTDB server</p><ul><li>Close a Session</li></ul><div class="language-java line-numbers-mode" data-ext="java"><pre class="language-java"><code><span class="token keyword">void</span> <span class="token function">close</span><span class="token punctuation">(</span><span class="token punctuation">)</span>
</code></pre><div class="line-numbers" aria-hidden="true"><div class="line-number"></div></div></div><h3 id="data-definition-interface-ddl-interface" tabindex="-1"><a class="header-anchor" href="#data-definition-interface-ddl-interface" aria-hidden="true">#</a> Data Definition Interface (DDL Interface)</h3><h4 id="database-management" tabindex="-1"><a class="header-anchor" href="#database-management" aria-hidden="true">#</a> Database Management</h4><ul><li>CREATE DATABASE</li></ul><div class="language-java line-numbers-mode" data-ext="java"><pre class="language-java"><code><span class="token keyword">void</span> <span class="token function">setStorageGroup</span><span class="token punctuation">(</span><span class="token class-name">String</span> storageGroupId<span class="token punctuation">)</span>    
</code></pre><div class="line-numbers" aria-hidden="true"><div class="line-number"></div></div></div><ul><li>Delete one or several databases</li></ul><div class="language-java line-numbers-mode" data-ext="java"><pre class="language-java"><code><span class="token keyword">void</span> <span class="token function">deleteStorageGroup</span><span class="token punctuation">(</span><span class="token class-name">String</span> storageGroup<span class="token punctuation">)</span>
<span class="token keyword">void</span> <span class="token function">deleteStorageGroups</span><span class="token punctuation">(</span><span class="token class-name">List</span><span class="token generics"><span class="token punctuation">&lt;</span><span class="token class-name">String</span><span class="token punctuation">&gt;</span></span> storageGroups<span class="token punctuation">)</span>
</code></pre><div class="line-numbers" aria-hidden="true"><div class="line-number"></div><div class="line-number"></div></div></div><h4 id="timeseries-management" tabindex="-1"><a class="header-anchor" href="#timeseries-management" aria-hidden="true">#</a> Timeseries Management</h4><ul><li>Create one or multiple timeseries</li></ul><div class="language-java line-numbers-mode" data-ext="java"><pre class="language-java"><code><span class="token keyword">void</span> <span class="token function">createTimeseries</span><span class="token punctuation">(</span><span class="token class-name">String</span> path<span class="token punctuation">,</span> <span class="token class-name">TSDataType</span> dataType<span class="token punctuation">,</span>
      <span class="token class-name">TSEncoding</span> encoding<span class="token punctuation">,</span> <span class="token class-name">CompressionType</span> compressor<span class="token punctuation">,</span> <span class="token class-name">Map</span><span class="token generics"><span class="token punctuation">&lt;</span><span class="token class-name">String</span><span class="token punctuation">,</span> <span class="token class-name">String</span><span class="token punctuation">&gt;</span></span> props<span class="token punctuation">,</span>
      <span class="token class-name">Map</span><span class="token generics"><span class="token punctuation">&lt;</span><span class="token class-name">String</span><span class="token punctuation">,</span> <span class="token class-name">String</span><span class="token punctuation">&gt;</span></span> tags<span class="token punctuation">,</span> <span class="token class-name">Map</span><span class="token generics"><span class="token punctuation">&lt;</span><span class="token class-name">String</span><span class="token punctuation">,</span> <span class="token class-name">String</span><span class="token punctuation">&gt;</span></span> attributes<span class="token punctuation">,</span> <span class="token class-name">String</span> measurementAlias<span class="token punctuation">)</span>
      
<span class="token keyword">void</span> <span class="token function">createMultiTimeseries</span><span class="token punctuation">(</span><span class="token class-name">List</span><span class="token generics"><span class="token punctuation">&lt;</span><span class="token class-name">String</span><span class="token punctuation">&gt;</span></span> paths<span class="token punctuation">,</span> <span class="token class-name">List</span><span class="token generics"><span class="token punctuation">&lt;</span><span class="token class-name">TSDataType</span><span class="token punctuation">&gt;</span></span> dataTypes<span class="token punctuation">,</span>
      <span class="token class-name">List</span><span class="token generics"><span class="token punctuation">&lt;</span><span class="token class-name">TSEncoding</span><span class="token punctuation">&gt;</span></span> encodings<span class="token punctuation">,</span> <span class="token class-name">List</span><span class="token generics"><span class="token punctuation">&lt;</span><span class="token class-name">CompressionType</span><span class="token punctuation">&gt;</span></span> compressors<span class="token punctuation">,</span>
      <span class="token class-name">List</span><span class="token generics"><span class="token punctuation">&lt;</span><span class="token class-name">Map</span><span class="token punctuation">&lt;</span><span class="token class-name">String</span><span class="token punctuation">,</span> <span class="token class-name">String</span><span class="token punctuation">&gt;</span><span class="token punctuation">&gt;</span></span> propsList<span class="token punctuation">,</span> <span class="token class-name">List</span><span class="token generics"><span class="token punctuation">&lt;</span><span class="token class-name">Map</span><span class="token punctuation">&lt;</span><span class="token class-name">String</span><span class="token punctuation">,</span> <span class="token class-name">String</span><span class="token punctuation">&gt;</span><span class="token punctuation">&gt;</span></span> tagsList<span class="token punctuation">,</span>
      <span class="token class-name">List</span><span class="token generics"><span class="token punctuation">&lt;</span><span class="token class-name">Map</span><span class="token punctuation">&lt;</span><span class="token class-name">String</span><span class="token punctuation">,</span> <span class="token class-name">String</span><span class="token punctuation">&gt;</span><span class="token punctuation">&gt;</span></span> attributesList<span class="token punctuation">,</span> <span class="token class-name">List</span><span class="token generics"><span class="token punctuation">&lt;</span><span class="token class-name">String</span><span class="token punctuation">&gt;</span></span> measurementAliasList<span class="token punctuation">)</span>
</code></pre><div class="line-numbers" aria-hidden="true"><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div></div></div><ul><li>Create aligned timeseries</li></ul><div class="language-text line-numbers-mode" data-ext="text"><pre class="language-text"><code>void createAlignedTimeseries(String prefixPath, List&lt;String&gt; measurements,
      List&lt;TSDataType&gt; dataTypes, List&lt;TSEncoding&gt; encodings,
      List &lt;CompressionType&gt; compressors, List&lt;String&gt; measurementAliasList);
</code></pre><div class="line-numbers" aria-hidden="true"><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div></div></div><p>Attention: Alias of measurements are <strong>not supported</strong> currently.</p><ul><li>Delete one or several timeseries</li></ul><div class="language-java line-numbers-mode" data-ext="java"><pre class="language-java"><code><span class="token keyword">void</span> <span class="token function">deleteTimeseries</span><span class="token punctuation">(</span><span class="token class-name">String</span> path<span class="token punctuation">)</span>
<span class="token keyword">void</span> <span class="token function">deleteTimeseries</span><span class="token punctuation">(</span><span class="token class-name">List</span><span class="token generics"><span class="token punctuation">&lt;</span><span class="token class-name">String</span><span class="token punctuation">&gt;</span></span> paths<span class="token punctuation">)</span>
</code></pre><div class="line-numbers" aria-hidden="true"><div class="line-number"></div><div class="line-number"></div></div></div><ul><li>Check whether the specific timeseries exists.</li></ul><div class="language-java line-numbers-mode" data-ext="java"><pre class="language-java"><code><span class="token keyword">boolean</span> <span class="token function">checkTimeseriesExists</span><span class="token punctuation">(</span><span class="token class-name">String</span> path<span class="token punctuation">)</span>
</code></pre><div class="line-numbers" aria-hidden="true"><div class="line-number"></div></div></div><h4 id="schema-template" tabindex="-1"><a class="header-anchor" href="#schema-template" aria-hidden="true">#</a> Schema Template</h4><p>Create a schema template for massive identical devices will help to improve memory performance. You can use Template, InternalNode and MeasurementNode to depict the structure of the template, and use belowed interface to create it inside session.</p><div class="language-java line-numbers-mode" data-ext="java"><pre class="language-java"><code><span class="token keyword">public</span> <span class="token keyword">void</span> <span class="token function">createSchemaTemplate</span><span class="token punctuation">(</span><span class="token class-name">Template</span> template<span class="token punctuation">)</span><span class="token punctuation">;</span>

<span class="token class-name">Class</span> <span class="token class-name">Template</span> <span class="token punctuation">{</span>
    <span class="token keyword">private</span> <span class="token class-name">String</span> name<span class="token punctuation">;</span>
    <span class="token keyword">private</span> <span class="token keyword">boolean</span> directShareTime<span class="token punctuation">;</span>
    <span class="token class-name">Map</span><span class="token generics"><span class="token punctuation">&lt;</span><span class="token class-name">String</span><span class="token punctuation">,</span> <span class="token class-name">Node</span><span class="token punctuation">&gt;</span></span> children<span class="token punctuation">;</span>
    <span class="token keyword">public</span> <span class="token class-name">Template</span><span class="token punctuation">(</span><span class="token class-name">String</span> name<span class="token punctuation">,</span> <span class="token keyword">boolean</span> isShareTime<span class="token punctuation">)</span><span class="token punctuation">;</span>
    
    <span class="token keyword">public</span> <span class="token keyword">void</span> <span class="token function">addToTemplate</span><span class="token punctuation">(</span><span class="token class-name">Node</span> node<span class="token punctuation">)</span><span class="token punctuation">;</span>
    <span class="token keyword">public</span> <span class="token keyword">void</span> <span class="token function">deleteFromTemplate</span><span class="token punctuation">(</span><span class="token class-name">String</span> name<span class="token punctuation">)</span><span class="token punctuation">;</span>
    <span class="token keyword">public</span> <span class="token keyword">void</span> <span class="token function">setShareTime</span><span class="token punctuation">(</span><span class="token keyword">boolean</span> shareTime<span class="token punctuation">)</span><span class="token punctuation">;</span>
<span class="token punctuation">}</span>

<span class="token class-name">Abstract</span> <span class="token class-name">Class</span> <span class="token class-name">Node</span> <span class="token punctuation">{</span>
    <span class="token keyword">private</span> <span class="token class-name">String</span> name<span class="token punctuation">;</span>
    <span class="token keyword">public</span> <span class="token keyword">void</span> <span class="token function">addChild</span><span class="token punctuation">(</span><span class="token class-name">Node</span> node<span class="token punctuation">)</span><span class="token punctuation">;</span>
    <span class="token keyword">public</span> <span class="token keyword">void</span> <span class="token function">deleteChild</span><span class="token punctuation">(</span><span class="token class-name">Node</span> node<span class="token punctuation">)</span><span class="token punctuation">;</span>
<span class="token punctuation">}</span>

<span class="token class-name">Class</span> <span class="token class-name">MeasurementNode</span> <span class="token keyword">extends</span> <span class="token class-name">Node</span> <span class="token punctuation">{</span>
    <span class="token class-name">TSDataType</span> dataType<span class="token punctuation">;</span>
    <span class="token class-name">TSEncoding</span> encoding<span class="token punctuation">;</span>
    <span class="token class-name">CompressionType</span> compressor<span class="token punctuation">;</span>
    <span class="token keyword">public</span> <span class="token class-name">MeasurementNode</span><span class="token punctuation">(</span><span class="token class-name">String</span> name<span class="token punctuation">,</span> 
                           <span class="token class-name">TSDataType</span> dataType<span class="token punctuation">,</span> 
                           <span class="token class-name">TSEncoding</span> encoding<span class="token punctuation">,</span>
                          <span class="token class-name">CompressionType</span> compressor<span class="token punctuation">)</span><span class="token punctuation">;</span>
<span class="token punctuation">}</span>
</code></pre><div class="line-numbers" aria-hidden="true"><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div></div></div><p>We strongly suggest you implement templates only with flat-measurement (like object &#39;flatTemplate&#39; in belowed snippet), since tree-structured template may not be a long-term supported feature in further version of IoTDB.</p><p>A snippet of using above Method and Class：</p><div class="language-java line-numbers-mode" data-ext="java"><pre class="language-java"><code><span class="token class-name">MeasurementNode</span> nodeX <span class="token operator">=</span> <span class="token keyword">new</span> <span class="token class-name">MeasurementNode</span><span class="token punctuation">(</span><span class="token string">&quot;x&quot;</span><span class="token punctuation">,</span> <span class="token class-name">TSDataType</span><span class="token punctuation">.</span><span class="token constant">FLOAT</span><span class="token punctuation">,</span> <span class="token class-name">TSEncoding</span><span class="token punctuation">.</span><span class="token constant">RLE</span><span class="token punctuation">,</span> <span class="token class-name">CompressionType</span><span class="token punctuation">.</span><span class="token constant">SNAPPY</span><span class="token punctuation">)</span><span class="token punctuation">;</span>
<span class="token class-name">MeasurementNode</span> nodeY <span class="token operator">=</span> <span class="token keyword">new</span> <span class="token class-name">MeasurementNode</span><span class="token punctuation">(</span><span class="token string">&quot;y&quot;</span><span class="token punctuation">,</span> <span class="token class-name">TSDataType</span><span class="token punctuation">.</span><span class="token constant">FLOAT</span><span class="token punctuation">,</span> <span class="token class-name">TSEncoding</span><span class="token punctuation">.</span><span class="token constant">RLE</span><span class="token punctuation">,</span> <span class="token class-name">CompressionType</span><span class="token punctuation">.</span><span class="token constant">SNAPPY</span><span class="token punctuation">)</span><span class="token punctuation">;</span>
<span class="token class-name">MeasurementNode</span> nodeSpeed <span class="token operator">=</span> <span class="token keyword">new</span> <span class="token class-name">MeasurementNode</span><span class="token punctuation">(</span><span class="token string">&quot;speed&quot;</span><span class="token punctuation">,</span> <span class="token class-name">TSDataType</span><span class="token punctuation">.</span><span class="token constant">DOUBLE</span><span class="token punctuation">,</span> <span class="token class-name">TSEncoding</span><span class="token punctuation">.</span><span class="token constant">GORILLA</span><span class="token punctuation">,</span> <span class="token class-name">CompressionType</span><span class="token punctuation">.</span><span class="token constant">SNAPPY</span><span class="token punctuation">)</span><span class="token punctuation">;</span>

<span class="token comment">// This is the template we suggest to implement</span>
<span class="token class-name">Template</span> flatTemplate <span class="token operator">=</span> <span class="token keyword">new</span> <span class="token class-name">Template</span><span class="token punctuation">(</span><span class="token string">&quot;flatTemplate&quot;</span><span class="token punctuation">)</span><span class="token punctuation">;</span>
template<span class="token punctuation">.</span><span class="token function">addToTemplate</span><span class="token punctuation">(</span>nodeX<span class="token punctuation">)</span><span class="token punctuation">;</span>
template<span class="token punctuation">.</span><span class="token function">addToTemplate</span><span class="token punctuation">(</span>nodeY<span class="token punctuation">)</span><span class="token punctuation">;</span>
template<span class="token punctuation">.</span><span class="token function">addToTemplate</span><span class="token punctuation">(</span>nodeSpeed<span class="token punctuation">)</span><span class="token punctuation">;</span>

<span class="token function">createSchemaTemplate</span><span class="token punctuation">(</span>flatTemplate<span class="token punctuation">)</span><span class="token punctuation">;</span>
</code></pre><div class="line-numbers" aria-hidden="true"><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div></div></div><p>You can query measurement inside templates with these APIS:</p><div class="language-java line-numbers-mode" data-ext="java"><pre class="language-java"><code><span class="token comment">// Return the amount of measurements inside a template</span>
<span class="token keyword">public</span> <span class="token keyword">int</span> <span class="token function">countMeasurementsInTemplate</span><span class="token punctuation">(</span><span class="token class-name">String</span> templateName<span class="token punctuation">)</span><span class="token punctuation">;</span>

<span class="token comment">// Return true if path points to a measurement, otherwise returne false</span>
<span class="token keyword">public</span> <span class="token keyword">boolean</span> <span class="token function">isMeasurementInTemplate</span><span class="token punctuation">(</span><span class="token class-name">String</span> templateName<span class="token punctuation">,</span> <span class="token class-name">String</span> path<span class="token punctuation">)</span><span class="token punctuation">;</span>

<span class="token comment">// Return true if path exists in template, otherwise return false</span>
<span class="token keyword">public</span> <span class="token keyword">boolean</span> <span class="token function">isPathExistInTemplate</span><span class="token punctuation">(</span><span class="token class-name">String</span> templateName<span class="token punctuation">,</span> <span class="token class-name">String</span> path<span class="token punctuation">)</span><span class="token punctuation">;</span>

<span class="token comment">// Return all measurements paths inside template</span>
<span class="token keyword">public</span> <span class="token class-name">List</span><span class="token generics"><span class="token punctuation">&lt;</span><span class="token class-name">String</span><span class="token punctuation">&gt;</span></span> <span class="token function">showMeasurementsInTemplate</span><span class="token punctuation">(</span><span class="token class-name">String</span> templateName<span class="token punctuation">)</span><span class="token punctuation">;</span>

<span class="token comment">// Return all measurements paths under the designated patter inside template</span>
<span class="token keyword">public</span> <span class="token class-name">List</span><span class="token generics"><span class="token punctuation">&lt;</span><span class="token class-name">String</span><span class="token punctuation">&gt;</span></span> <span class="token function">showMeasurementsInTemplate</span><span class="token punctuation">(</span><span class="token class-name">String</span> templateName<span class="token punctuation">,</span> <span class="token class-name">String</span> pattern<span class="token punctuation">)</span><span class="token punctuation">;</span>
</code></pre><div class="line-numbers" aria-hidden="true"><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div></div></div><p>To implement schema template, you can set the measurement template named &#39;templateName&#39; at path &#39;prefixPath&#39;.</p><p><strong>Please notice that, we strongly recommend not setting templates on the nodes above the database to accommodate future updates and collaboration between modules.</strong></p><div class="language-java line-numbers-mode" data-ext="java"><pre class="language-java"><code><span class="token keyword">void</span> <span class="token function">setSchemaTemplate</span><span class="token punctuation">(</span><span class="token class-name">String</span> templateName<span class="token punctuation">,</span> <span class="token class-name">String</span> prefixPath<span class="token punctuation">)</span>
</code></pre><div class="line-numbers" aria-hidden="true"><div class="line-number"></div></div></div><p>Before setting template, you should firstly create the template using</p><div class="language-java line-numbers-mode" data-ext="java"><pre class="language-java"><code><span class="token keyword">void</span> <span class="token function">createSchemaTemplate</span><span class="token punctuation">(</span><span class="token class-name">Template</span> template<span class="token punctuation">)</span>
</code></pre><div class="line-numbers" aria-hidden="true"><div class="line-number"></div></div></div><p>After setting template to a certain path, you can use the template to create timeseries on given device paths through the following interface, or you can write data directly to trigger timeseries auto creation using schema template under target devices.</p><div class="language-java line-numbers-mode" data-ext="java"><pre class="language-java"><code><span class="token keyword">void</span> <span class="token function">createTimeseriesUsingSchemaTemplate</span><span class="token punctuation">(</span><span class="token class-name">List</span><span class="token generics"><span class="token punctuation">&lt;</span><span class="token class-name">String</span><span class="token punctuation">&gt;</span></span> devicePathList<span class="token punctuation">)</span>
</code></pre><div class="line-numbers" aria-hidden="true"><div class="line-number"></div></div></div><p>After setting template to a certain path, you can query for info about template using belowed interface in session:</p><div class="language-java line-numbers-mode" data-ext="java"><pre class="language-java"><code><span class="token doc-comment comment">/** <span class="token keyword">@return</span> All template names. */</span>
<span class="token keyword">public</span> <span class="token class-name">List</span><span class="token generics"><span class="token punctuation">&lt;</span><span class="token class-name">String</span><span class="token punctuation">&gt;</span></span> <span class="token function">showAllTemplates</span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token punctuation">;</span>

<span class="token doc-comment comment">/** <span class="token keyword">@return</span> All paths have been set to designated template. */</span>
<span class="token keyword">public</span> <span class="token class-name">List</span><span class="token generics"><span class="token punctuation">&lt;</span><span class="token class-name">String</span><span class="token punctuation">&gt;</span></span> <span class="token function">showPathsTemplateSetOn</span><span class="token punctuation">(</span><span class="token class-name">String</span> templateName<span class="token punctuation">)</span><span class="token punctuation">;</span>

<span class="token doc-comment comment">/** <span class="token keyword">@return</span> All paths are using designated template. */</span>
<span class="token keyword">public</span> <span class="token class-name">List</span><span class="token generics"><span class="token punctuation">&lt;</span><span class="token class-name">String</span><span class="token punctuation">&gt;</span></span> <span class="token function">showPathsTemplateUsingOn</span><span class="token punctuation">(</span><span class="token class-name">String</span> templateName<span class="token punctuation">)</span>
</code></pre><div class="line-numbers" aria-hidden="true"><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div></div></div><p>If you are ready to get rid of schema template, you can drop it with belowed interface. Make sure the template to drop has been unset from MTree.</p><div class="language-java line-numbers-mode" data-ext="java"><pre class="language-java"><code><span class="token keyword">void</span> <span class="token function">unsetSchemaTemplate</span><span class="token punctuation">(</span><span class="token class-name">String</span> prefixPath<span class="token punctuation">,</span> <span class="token class-name">String</span> templateName<span class="token punctuation">)</span><span class="token punctuation">;</span>
<span class="token keyword">public</span> <span class="token keyword">void</span> <span class="token function">dropSchemaTemplate</span><span class="token punctuation">(</span><span class="token class-name">String</span> templateName<span class="token punctuation">)</span><span class="token punctuation">;</span>
</code></pre><div class="line-numbers" aria-hidden="true"><div class="line-number"></div><div class="line-number"></div></div></div><p>Unset the measurement template named &#39;templateName&#39; from path &#39;prefixPath&#39;. When you issue this interface, you should assure that there is a template named &#39;templateName&#39; set at the path &#39;prefixPath&#39;.</p><p>Attention: Unsetting the template named &#39;templateName&#39; from node at path &#39;prefixPath&#39; or descendant nodes which have already inserted records using template is <strong>not supported</strong>.</p><h3 id="data-manipulation-interface-dml-interface" tabindex="-1"><a class="header-anchor" href="#data-manipulation-interface-dml-interface" aria-hidden="true">#</a> Data Manipulation Interface (DML Interface)</h3><h4 id="insert" tabindex="-1"><a class="header-anchor" href="#insert" aria-hidden="true">#</a> Insert</h4><p>It is recommended to use insertTablet to help improve write efficiency.</p><ul><li>Insert a Tablet，which is multiple rows of a device, each row has the same measurements <ul><li><strong>Better Write Performance</strong></li><li><strong>Support batch write</strong></li><li><strong>Support null values</strong>: fill the null value with any value, and then mark the null value via BitMap</li></ul></li></ul><div class="language-java line-numbers-mode" data-ext="java"><pre class="language-java"><code><span class="token keyword">void</span> <span class="token function">insertTablet</span><span class="token punctuation">(</span><span class="token class-name">Tablet</span> tablet<span class="token punctuation">)</span>

<span class="token keyword">public</span> <span class="token keyword">class</span> <span class="token class-name">Tablet</span> <span class="token punctuation">{</span>
  <span class="token doc-comment comment">/** deviceId of this tablet */</span>
  <span class="token keyword">public</span> <span class="token class-name">String</span> prefixPath<span class="token punctuation">;</span>
  <span class="token doc-comment comment">/** the list of measurement schemas for creating the tablet */</span>
  <span class="token keyword">private</span> <span class="token class-name">List</span><span class="token generics"><span class="token punctuation">&lt;</span><span class="token class-name">MeasurementSchema</span><span class="token punctuation">&gt;</span></span> schemas<span class="token punctuation">;</span>
  <span class="token doc-comment comment">/** timestamps in this tablet */</span>
  <span class="token keyword">public</span> <span class="token keyword">long</span><span class="token punctuation">[</span><span class="token punctuation">]</span> timestamps<span class="token punctuation">;</span>
  <span class="token doc-comment comment">/** each object is a primitive type array, which represents values of one measurement */</span>
  <span class="token keyword">public</span> <span class="token class-name">Object</span><span class="token punctuation">[</span><span class="token punctuation">]</span> values<span class="token punctuation">;</span>
  <span class="token doc-comment comment">/** each bitmap represents the existence of each value in the current column. */</span>
  <span class="token keyword">public</span> <span class="token class-name">BitMap</span><span class="token punctuation">[</span><span class="token punctuation">]</span> bitMaps<span class="token punctuation">;</span>
  <span class="token doc-comment comment">/** the number of rows to include in this tablet */</span>
  <span class="token keyword">public</span> <span class="token keyword">int</span> rowSize<span class="token punctuation">;</span>
  <span class="token doc-comment comment">/** the maximum number of rows for this tablet */</span>
  <span class="token keyword">private</span> <span class="token keyword">int</span> maxRowNumber<span class="token punctuation">;</span>
  <span class="token doc-comment comment">/** whether this tablet store data of aligned timeseries or not */</span>
  <span class="token keyword">private</span> <span class="token keyword">boolean</span> isAligned<span class="token punctuation">;</span>
<span class="token punctuation">}</span>
</code></pre><div class="line-numbers" aria-hidden="true"><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div></div></div><ul><li>Insert multiple Tablets</li></ul><div class="language-java line-numbers-mode" data-ext="java"><pre class="language-java"><code><span class="token keyword">void</span> <span class="token function">insertTablets</span><span class="token punctuation">(</span><span class="token class-name">Map</span><span class="token generics"><span class="token punctuation">&lt;</span><span class="token class-name">String</span><span class="token punctuation">,</span> <span class="token class-name">Tablet</span><span class="token punctuation">&gt;</span></span> tablet<span class="token punctuation">)</span>
</code></pre><div class="line-numbers" aria-hidden="true"><div class="line-number"></div></div></div><ul><li><p>Insert a Record, which contains multiple measurement value of a device at a timestamp. This method is equivalent to providing a common interface for multiple data types of values. Later, the value can be cast to the original type through TSDataType.</p><p>The correspondence between the Object type and the TSDataType type is shown in the following table.</p><table><thead><tr><th>TSDataType</th><th>Object</th></tr></thead><tbody><tr><td>BOOLEAN</td><td>Boolean</td></tr><tr><td>INT32</td><td>Integer</td></tr><tr><td>INT64</td><td>Long</td></tr><tr><td>FLOAT</td><td>Float</td></tr><tr><td>DOUBLE</td><td>Double</td></tr><tr><td>TEXT</td><td>String, Binary</td></tr></tbody></table></li></ul><div class="language-java line-numbers-mode" data-ext="java"><pre class="language-java"><code><span class="token keyword">void</span> <span class="token function">insertRecord</span><span class="token punctuation">(</span><span class="token class-name">String</span> deviceId<span class="token punctuation">,</span> <span class="token keyword">long</span> time<span class="token punctuation">,</span> <span class="token class-name">List</span><span class="token generics"><span class="token punctuation">&lt;</span><span class="token class-name">String</span><span class="token punctuation">&gt;</span></span> measurements<span class="token punctuation">,</span>
   <span class="token class-name">List</span><span class="token generics"><span class="token punctuation">&lt;</span><span class="token class-name">TSDataType</span><span class="token punctuation">&gt;</span></span> types<span class="token punctuation">,</span> <span class="token class-name">List</span><span class="token generics"><span class="token punctuation">&lt;</span><span class="token class-name">Object</span><span class="token punctuation">&gt;</span></span> values<span class="token punctuation">)</span>
</code></pre><div class="line-numbers" aria-hidden="true"><div class="line-number"></div><div class="line-number"></div></div></div><ul><li>Insert multiple Records</li></ul><div class="language-java line-numbers-mode" data-ext="java"><pre class="language-java"><code><span class="token keyword">void</span> <span class="token function">insertRecords</span><span class="token punctuation">(</span><span class="token class-name">List</span><span class="token generics"><span class="token punctuation">&lt;</span><span class="token class-name">String</span><span class="token punctuation">&gt;</span></span> deviceIds<span class="token punctuation">,</span> <span class="token class-name">List</span><span class="token generics"><span class="token punctuation">&lt;</span><span class="token class-name">Long</span><span class="token punctuation">&gt;</span></span> times<span class="token punctuation">,</span>
    <span class="token class-name">List</span><span class="token generics"><span class="token punctuation">&lt;</span><span class="token class-name">List</span><span class="token punctuation">&lt;</span><span class="token class-name">String</span><span class="token punctuation">&gt;</span><span class="token punctuation">&gt;</span></span> measurementsList<span class="token punctuation">,</span> <span class="token class-name">List</span><span class="token generics"><span class="token punctuation">&lt;</span><span class="token class-name">List</span><span class="token punctuation">&lt;</span><span class="token class-name">TSDataType</span><span class="token punctuation">&gt;</span><span class="token punctuation">&gt;</span></span> typesList<span class="token punctuation">,</span>
    <span class="token class-name">List</span><span class="token generics"><span class="token punctuation">&lt;</span><span class="token class-name">List</span><span class="token punctuation">&lt;</span><span class="token class-name">Object</span><span class="token punctuation">&gt;</span><span class="token punctuation">&gt;</span></span> valuesList<span class="token punctuation">)</span>
</code></pre><div class="line-numbers" aria-hidden="true"><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div></div></div><ul><li>Insert multiple Records that belong to the same device.<br> With type info the server has no need to do type inference, which leads a better performance</li></ul><div class="language-java line-numbers-mode" data-ext="java"><pre class="language-java"><code><span class="token keyword">void</span> <span class="token function">insertRecordsOfOneDevice</span><span class="token punctuation">(</span><span class="token class-name">String</span> deviceId<span class="token punctuation">,</span> <span class="token class-name">List</span><span class="token generics"><span class="token punctuation">&lt;</span><span class="token class-name">Long</span><span class="token punctuation">&gt;</span></span> times<span class="token punctuation">,</span>
    <span class="token class-name">List</span><span class="token generics"><span class="token punctuation">&lt;</span><span class="token class-name">List</span><span class="token punctuation">&lt;</span><span class="token class-name">String</span><span class="token punctuation">&gt;</span><span class="token punctuation">&gt;</span></span> measurementsList<span class="token punctuation">,</span> <span class="token class-name">List</span><span class="token generics"><span class="token punctuation">&lt;</span><span class="token class-name">List</span><span class="token punctuation">&lt;</span><span class="token class-name">TSDataType</span><span class="token punctuation">&gt;</span><span class="token punctuation">&gt;</span></span> typesList<span class="token punctuation">,</span>
    <span class="token class-name">List</span><span class="token generics"><span class="token punctuation">&lt;</span><span class="token class-name">List</span><span class="token punctuation">&lt;</span><span class="token class-name">Object</span><span class="token punctuation">&gt;</span><span class="token punctuation">&gt;</span></span> valuesList<span class="token punctuation">)</span>
</code></pre><div class="line-numbers" aria-hidden="true"><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div></div></div><h4 id="insert-with-type-inference" tabindex="-1"><a class="header-anchor" href="#insert-with-type-inference" aria-hidden="true">#</a> Insert with type inference</h4><p>When the data is of String type, we can use the following interface to perform type inference based on the value of the value itself. For example, if value is &quot;true&quot; , it can be automatically inferred to be a boolean type. If value is &quot;3.2&quot; , it can be automatically inferred as a flout type. Without type information, server has to do type inference, which may cost some time.</p><ul><li>Insert a Record, which contains multiple measurement value of a device at a timestamp</li></ul><div class="language-java line-numbers-mode" data-ext="java"><pre class="language-java"><code><span class="token keyword">void</span> <span class="token function">insertRecord</span><span class="token punctuation">(</span><span class="token class-name">String</span> prefixPath<span class="token punctuation">,</span> <span class="token keyword">long</span> time<span class="token punctuation">,</span> <span class="token class-name">List</span><span class="token generics"><span class="token punctuation">&lt;</span><span class="token class-name">String</span><span class="token punctuation">&gt;</span></span> measurements<span class="token punctuation">,</span> <span class="token class-name">List</span><span class="token generics"><span class="token punctuation">&lt;</span><span class="token class-name">String</span><span class="token punctuation">&gt;</span></span> values<span class="token punctuation">)</span>
</code></pre><div class="line-numbers" aria-hidden="true"><div class="line-number"></div></div></div><ul><li>Insert multiple Records</li></ul><div class="language-java line-numbers-mode" data-ext="java"><pre class="language-java"><code><span class="token keyword">void</span> <span class="token function">insertRecords</span><span class="token punctuation">(</span><span class="token class-name">List</span><span class="token generics"><span class="token punctuation">&lt;</span><span class="token class-name">String</span><span class="token punctuation">&gt;</span></span> deviceIds<span class="token punctuation">,</span> <span class="token class-name">List</span><span class="token generics"><span class="token punctuation">&lt;</span><span class="token class-name">Long</span><span class="token punctuation">&gt;</span></span> times<span class="token punctuation">,</span> 
   <span class="token class-name">List</span><span class="token generics"><span class="token punctuation">&lt;</span><span class="token class-name">List</span><span class="token punctuation">&lt;</span><span class="token class-name">String</span><span class="token punctuation">&gt;</span><span class="token punctuation">&gt;</span></span> measurementsList<span class="token punctuation">,</span> <span class="token class-name">List</span><span class="token generics"><span class="token punctuation">&lt;</span><span class="token class-name">List</span><span class="token punctuation">&lt;</span><span class="token class-name">String</span><span class="token punctuation">&gt;</span><span class="token punctuation">&gt;</span></span> valuesList<span class="token punctuation">)</span>
</code></pre><div class="line-numbers" aria-hidden="true"><div class="line-number"></div><div class="line-number"></div></div></div><ul><li>Insert multiple Records that belong to the same device.</li></ul><div class="language-java line-numbers-mode" data-ext="java"><pre class="language-java"><code><span class="token keyword">void</span> <span class="token function">insertStringRecordsOfOneDevice</span><span class="token punctuation">(</span><span class="token class-name">String</span> deviceId<span class="token punctuation">,</span> <span class="token class-name">List</span><span class="token generics"><span class="token punctuation">&lt;</span><span class="token class-name">Long</span><span class="token punctuation">&gt;</span></span> times<span class="token punctuation">,</span>
        <span class="token class-name">List</span><span class="token generics"><span class="token punctuation">&lt;</span><span class="token class-name">List</span><span class="token punctuation">&lt;</span><span class="token class-name">String</span><span class="token punctuation">&gt;</span><span class="token punctuation">&gt;</span></span> measurementsList<span class="token punctuation">,</span> <span class="token class-name">List</span><span class="token generics"><span class="token punctuation">&lt;</span><span class="token class-name">List</span><span class="token punctuation">&lt;</span><span class="token class-name">String</span><span class="token punctuation">&gt;</span><span class="token punctuation">&gt;</span></span> valuesList<span class="token punctuation">)</span>
</code></pre><div class="line-numbers" aria-hidden="true"><div class="line-number"></div><div class="line-number"></div></div></div><h4 id="insert-of-aligned-timeseries" tabindex="-1"><a class="header-anchor" href="#insert-of-aligned-timeseries" aria-hidden="true">#</a> Insert of Aligned Timeseries</h4><p>The Insert of aligned timeseries uses interfaces like insertAlignedXXX, and others are similar to the above interfaces:</p><ul><li>insertAlignedRecord</li><li>insertAlignedRecords</li><li>insertAlignedRecordsOfOneDevice</li><li>insertAlignedStringRecordsOfOneDevice</li><li>insertAlignedTablet</li><li>insertAlignedTablets</li></ul><h4 id="delete" tabindex="-1"><a class="header-anchor" href="#delete" aria-hidden="true">#</a> Delete</h4><ul><li>Delete data before or equal to a timestamp of one or several timeseries</li></ul><div class="language-java line-numbers-mode" data-ext="java"><pre class="language-java"><code><span class="token keyword">void</span> <span class="token function">deleteData</span><span class="token punctuation">(</span><span class="token class-name">String</span> path<span class="token punctuation">,</span> <span class="token keyword">long</span> time<span class="token punctuation">)</span>
<span class="token keyword">void</span> <span class="token function">deleteData</span><span class="token punctuation">(</span><span class="token class-name">List</span><span class="token generics"><span class="token punctuation">&lt;</span><span class="token class-name">String</span><span class="token punctuation">&gt;</span></span> paths<span class="token punctuation">,</span> <span class="token keyword">long</span> time<span class="token punctuation">)</span>
</code></pre><div class="line-numbers" aria-hidden="true"><div class="line-number"></div><div class="line-number"></div></div></div><h4 id="query" tabindex="-1"><a class="header-anchor" href="#query" aria-hidden="true">#</a> Query</h4><ul><li>Time-series raw data query with time range: <ul><li>The specified query time range is a left-closed right-open interval, including the start time but excluding the end time.</li></ul></li></ul><div class="language-java line-numbers-mode" data-ext="java"><pre class="language-java"><code><span class="token class-name">SessionDataSet</span> <span class="token function">executeRawDataQuery</span><span class="token punctuation">(</span><span class="token class-name">List</span><span class="token generics"><span class="token punctuation">&lt;</span><span class="token class-name">String</span><span class="token punctuation">&gt;</span></span> paths<span class="token punctuation">,</span> <span class="token keyword">long</span> startTime<span class="token punctuation">,</span> <span class="token keyword">long</span> endTime<span class="token punctuation">)</span><span class="token punctuation">;</span>
</code></pre><div class="line-numbers" aria-hidden="true"><div class="line-number"></div></div></div><ul><li><p>Last query:</p><ul><li>Query the last data, whose timestamp is greater than or equal LastTime.<div class="language-java line-numbers-mode" data-ext="java"><pre class="language-java"><code><span class="token class-name">SessionDataSet</span> <span class="token function">executeLastDataQuery</span><span class="token punctuation">(</span><span class="token class-name">List</span><span class="token generics"><span class="token punctuation">&lt;</span><span class="token class-name">String</span><span class="token punctuation">&gt;</span></span> paths<span class="token punctuation">,</span> <span class="token keyword">long</span> <span class="token class-name">LastTime</span><span class="token punctuation">)</span><span class="token punctuation">;</span>
</code></pre><div class="line-numbers" aria-hidden="true"><div class="line-number"></div></div></div></li><li>Query the latest point of the specified series of single device quickly, and support redirection;<br> If you are sure that the query path is valid, set &#39;isLegalPathNodes&#39; to true to avoid performance penalties from path verification.<div class="language-java line-numbers-mode" data-ext="java"><pre class="language-java"><code><span class="token class-name">SessionDataSet</span> <span class="token function">executeLastDataQueryForOneDevice</span><span class="token punctuation">(</span>
    <span class="token class-name">String</span> db<span class="token punctuation">,</span> <span class="token class-name">String</span> device<span class="token punctuation">,</span> <span class="token class-name">List</span><span class="token generics"><span class="token punctuation">&lt;</span><span class="token class-name">String</span><span class="token punctuation">&gt;</span></span> sensors<span class="token punctuation">,</span> <span class="token keyword">boolean</span> isLegalPathNodes<span class="token punctuation">)</span><span class="token punctuation">;</span>
</code></pre><div class="line-numbers" aria-hidden="true"><div class="line-number"></div><div class="line-number"></div></div></div></li></ul></li><li><p>Aggregation query:</p><ul><li>Support specified query time range: The specified query time range is a left-closed right-open interval, including the start time but not the end time.</li><li>Support GROUP BY TIME.</li></ul></li></ul><div class="language-java line-numbers-mode" data-ext="java"><pre class="language-java"><code><span class="token class-name">SessionDataSet</span> <span class="token function">executeAggregationQuery</span><span class="token punctuation">(</span><span class="token class-name">List</span><span class="token generics"><span class="token punctuation">&lt;</span><span class="token class-name">String</span><span class="token punctuation">&gt;</span></span> paths<span class="token punctuation">,</span> <span class="token class-name">List</span><span class="token generics"><span class="token punctuation">&lt;</span><span class="token class-name">Aggregation</span><span class="token punctuation">&gt;</span></span> aggregations<span class="token punctuation">)</span><span class="token punctuation">;</span>

<span class="token class-name">SessionDataSet</span> <span class="token function">executeAggregationQuery</span><span class="token punctuation">(</span>
    <span class="token class-name">List</span><span class="token generics"><span class="token punctuation">&lt;</span><span class="token class-name">String</span><span class="token punctuation">&gt;</span></span> paths<span class="token punctuation">,</span> <span class="token class-name">List</span><span class="token generics"><span class="token punctuation">&lt;</span><span class="token class-name">Aggregation</span><span class="token punctuation">&gt;</span></span> aggregations<span class="token punctuation">,</span> <span class="token keyword">long</span> startTime<span class="token punctuation">,</span> <span class="token keyword">long</span> endTime<span class="token punctuation">)</span><span class="token punctuation">;</span>

<span class="token class-name">SessionDataSet</span> <span class="token function">executeAggregationQuery</span><span class="token punctuation">(</span>
    <span class="token class-name">List</span><span class="token generics"><span class="token punctuation">&lt;</span><span class="token class-name">String</span><span class="token punctuation">&gt;</span></span> paths<span class="token punctuation">,</span>
    <span class="token class-name">List</span><span class="token generics"><span class="token punctuation">&lt;</span><span class="token class-name">Aggregation</span><span class="token punctuation">&gt;</span></span> aggregations<span class="token punctuation">,</span>
    <span class="token keyword">long</span> startTime<span class="token punctuation">,</span>
    <span class="token keyword">long</span> endTime<span class="token punctuation">,</span>
    <span class="token keyword">long</span> interval<span class="token punctuation">)</span><span class="token punctuation">;</span>

<span class="token class-name">SessionDataSet</span> <span class="token function">executeAggregationQuery</span><span class="token punctuation">(</span>
    <span class="token class-name">List</span><span class="token generics"><span class="token punctuation">&lt;</span><span class="token class-name">String</span><span class="token punctuation">&gt;</span></span> paths<span class="token punctuation">,</span>
    <span class="token class-name">List</span><span class="token generics"><span class="token punctuation">&lt;</span><span class="token class-name">Aggregation</span><span class="token punctuation">&gt;</span></span> aggregations<span class="token punctuation">,</span>
    <span class="token keyword">long</span> startTime<span class="token punctuation">,</span>
    <span class="token keyword">long</span> endTime<span class="token punctuation">,</span>
    <span class="token keyword">long</span> interval<span class="token punctuation">,</span>
    <span class="token keyword">long</span> slidingStep<span class="token punctuation">)</span><span class="token punctuation">;</span>
</code></pre><div class="line-numbers" aria-hidden="true"><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div></div></div><h3 id="iotdb-sql-interface" tabindex="-1"><a class="header-anchor" href="#iotdb-sql-interface" aria-hidden="true">#</a> IoTDB-SQL Interface</h3><ul><li>Execute query statement</li></ul><div class="language-java line-numbers-mode" data-ext="java"><pre class="language-java"><code><span class="token class-name">SessionDataSet</span> <span class="token function">executeQueryStatement</span><span class="token punctuation">(</span><span class="token class-name">String</span> sql<span class="token punctuation">)</span>
</code></pre><div class="line-numbers" aria-hidden="true"><div class="line-number"></div></div></div><ul><li>Execute non query statement</li></ul><div class="language-java line-numbers-mode" data-ext="java"><pre class="language-java"><code><span class="token keyword">void</span> <span class="token function">executeNonQueryStatement</span><span class="token punctuation">(</span><span class="token class-name">String</span> sql<span class="token punctuation">)</span>
</code></pre><div class="line-numbers" aria-hidden="true"><div class="line-number"></div></div></div><h3 id="write-test-interface-to-profile-network-cost" tabindex="-1"><a class="header-anchor" href="#write-test-interface-to-profile-network-cost" aria-hidden="true">#</a> Write Test Interface (to profile network cost)</h3><p>These methods <strong>don&#39;t</strong> insert data into database and server just return after accept the request.</p><ul><li>Test the network and client cost of insertRecord</li></ul><div class="language-java line-numbers-mode" data-ext="java"><pre class="language-java"><code><span class="token keyword">void</span> <span class="token function">testInsertRecord</span><span class="token punctuation">(</span><span class="token class-name">String</span> deviceId<span class="token punctuation">,</span> <span class="token keyword">long</span> time<span class="token punctuation">,</span> <span class="token class-name">List</span><span class="token generics"><span class="token punctuation">&lt;</span><span class="token class-name">String</span><span class="token punctuation">&gt;</span></span> measurements<span class="token punctuation">,</span> <span class="token class-name">List</span><span class="token generics"><span class="token punctuation">&lt;</span><span class="token class-name">String</span><span class="token punctuation">&gt;</span></span> values<span class="token punctuation">)</span>

<span class="token keyword">void</span> <span class="token function">testInsertRecord</span><span class="token punctuation">(</span><span class="token class-name">String</span> deviceId<span class="token punctuation">,</span> <span class="token keyword">long</span> time<span class="token punctuation">,</span> <span class="token class-name">List</span><span class="token generics"><span class="token punctuation">&lt;</span><span class="token class-name">String</span><span class="token punctuation">&gt;</span></span> measurements<span class="token punctuation">,</span>
        <span class="token class-name">List</span><span class="token generics"><span class="token punctuation">&lt;</span><span class="token class-name">TSDataType</span><span class="token punctuation">&gt;</span></span> types<span class="token punctuation">,</span> <span class="token class-name">List</span><span class="token generics"><span class="token punctuation">&lt;</span><span class="token class-name">Object</span><span class="token punctuation">&gt;</span></span> values<span class="token punctuation">)</span>
</code></pre><div class="line-numbers" aria-hidden="true"><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div></div></div><ul><li>Test the network and client cost of insertRecords</li></ul><div class="language-java line-numbers-mode" data-ext="java"><pre class="language-java"><code><span class="token keyword">void</span> <span class="token function">testInsertRecords</span><span class="token punctuation">(</span><span class="token class-name">List</span><span class="token generics"><span class="token punctuation">&lt;</span><span class="token class-name">String</span><span class="token punctuation">&gt;</span></span> deviceIds<span class="token punctuation">,</span> <span class="token class-name">List</span><span class="token generics"><span class="token punctuation">&lt;</span><span class="token class-name">Long</span><span class="token punctuation">&gt;</span></span> times<span class="token punctuation">,</span>
        <span class="token class-name">List</span><span class="token generics"><span class="token punctuation">&lt;</span><span class="token class-name">List</span><span class="token punctuation">&lt;</span><span class="token class-name">String</span><span class="token punctuation">&gt;</span><span class="token punctuation">&gt;</span></span> measurementsList<span class="token punctuation">,</span> <span class="token class-name">List</span><span class="token generics"><span class="token punctuation">&lt;</span><span class="token class-name">List</span><span class="token punctuation">&lt;</span><span class="token class-name">String</span><span class="token punctuation">&gt;</span><span class="token punctuation">&gt;</span></span> valuesList<span class="token punctuation">)</span>
        
<span class="token keyword">void</span> <span class="token function">testInsertRecords</span><span class="token punctuation">(</span><span class="token class-name">List</span><span class="token generics"><span class="token punctuation">&lt;</span><span class="token class-name">String</span><span class="token punctuation">&gt;</span></span> deviceIds<span class="token punctuation">,</span> <span class="token class-name">List</span><span class="token generics"><span class="token punctuation">&lt;</span><span class="token class-name">Long</span><span class="token punctuation">&gt;</span></span> times<span class="token punctuation">,</span>
        <span class="token class-name">List</span><span class="token generics"><span class="token punctuation">&lt;</span><span class="token class-name">List</span><span class="token punctuation">&lt;</span><span class="token class-name">String</span><span class="token punctuation">&gt;</span><span class="token punctuation">&gt;</span></span> measurementsList<span class="token punctuation">,</span> <span class="token class-name">List</span><span class="token generics"><span class="token punctuation">&lt;</span><span class="token class-name">List</span><span class="token punctuation">&lt;</span><span class="token class-name">TSDataType</span><span class="token punctuation">&gt;</span><span class="token punctuation">&gt;</span></span> typesList
        <span class="token class-name">List</span><span class="token generics"><span class="token punctuation">&lt;</span><span class="token class-name">List</span><span class="token punctuation">&lt;</span><span class="token class-name">Object</span><span class="token punctuation">&gt;</span><span class="token punctuation">&gt;</span></span> valuesList<span class="token punctuation">)</span>
</code></pre><div class="line-numbers" aria-hidden="true"><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div></div></div><ul><li>Test the network and client cost of insertTablet</li></ul><div class="language-java line-numbers-mode" data-ext="java"><pre class="language-java"><code><span class="token keyword">void</span> <span class="token function">testInsertTablet</span><span class="token punctuation">(</span><span class="token class-name">Tablet</span> tablet<span class="token punctuation">)</span>
</code></pre><div class="line-numbers" aria-hidden="true"><div class="line-number"></div></div></div><ul><li>Test the network and client cost of insertTablets</li></ul><div class="language-java line-numbers-mode" data-ext="java"><pre class="language-java"><code><span class="token keyword">void</span> <span class="token function">testInsertTablets</span><span class="token punctuation">(</span><span class="token class-name">Map</span><span class="token generics"><span class="token punctuation">&lt;</span><span class="token class-name">String</span><span class="token punctuation">,</span> <span class="token class-name">Tablet</span><span class="token punctuation">&gt;</span></span> tablets<span class="token punctuation">)</span>
</code></pre><div class="line-numbers" aria-hidden="true"><div class="line-number"></div></div></div><h3 id="coding-examples" tabindex="-1"><a class="header-anchor" href="#coding-examples" aria-hidden="true">#</a> Coding Examples</h3><p>To get more information of the following interfaces, please view session/src/main/java/org/apache/iotdb/session/Session.java</p><p>The sample code of using these interfaces is in example/session/src/main/java/org/apache/iotdb/SessionExample.java，which provides an example of how to open an IoTDB session, execute a batch insertion.</p><p>For examples of aligned timeseries and measurement template, you can refer to <code>example/session/src/main/java/org/apache/iotdb/AlignedTimeseriesSessionExample.java</code></p><h2 id="session-pool-for-native-api" tabindex="-1"><a class="header-anchor" href="#session-pool-for-native-api" aria-hidden="true">#</a> Session Pool for Native API</h2><p>We provide a connection pool (\`SessionPool) for Native API.<br> Using the interface, you need to define the pool size.</p><p>If you can not get a session connection in 60 seconds, there is a warning log but the program will hang.</p><p>If a session has finished an operation, it will be put back to the pool automatically.<br> If a session connection is broken, the session will be removed automatically and the pool will try<br> to create a new session and redo the operation.<br> You can also specify an url list of multiple reachable nodes when creating a SessionPool, just as you would when creating a Session. To ensure high availability of clients in distributed cluster.</p><p>For query operations:</p><ol><li>When using SessionPool to query data, the result set is <code>SessionDataSetWrapper</code>;</li><li>Given a <code>SessionDataSetWrapper</code>, if you have not scanned all the data in it and stop to use it,<br> you have to call <code>SessionPool.closeResultSet(wrapper)</code> manually;</li><li>When you call <code>hasNext()</code> and <code>next()</code> of a <code>SessionDataSetWrapper</code> and there is an exception, then<br> you have to call <code>SessionPool.closeResultSet(wrapper)</code> manually;</li><li>You can call <code>getColumnNames()</code> of <code>SessionDataSetWrapper</code> to get the column names of query result;</li></ol><p>Examples: <code>session/src/test/java/org/apache/iotdb/session/pool/SessionPoolTest.java</code></p><p>Or <code>example/session/src/main/java/org/apache/iotdb/SessionPoolExample.java</code></p><h2 id="cluster-information-related-apis-only-works-in-the-cluster-mode" tabindex="-1"><a class="header-anchor" href="#cluster-information-related-apis-only-works-in-the-cluster-mode" aria-hidden="true">#</a> Cluster information related APIs (only works in the cluster mode)</h2><p>Cluster information related APIs allow users get the cluster info like where a database will be<br> partitioned to, the status of each node in the cluster.</p><p>To use the APIs, add dependency in your pom file:</p><div class="language-xml line-numbers-mode" data-ext="xml"><pre class="language-xml"><code><span class="token tag"><span class="token tag"><span class="token punctuation">&lt;</span>dependencies</span><span class="token punctuation">&gt;</span></span>
    <span class="token tag"><span class="token tag"><span class="token punctuation">&lt;</span>dependency</span><span class="token punctuation">&gt;</span></span>
      <span class="token tag"><span class="token tag"><span class="token punctuation">&lt;</span>groupId</span><span class="token punctuation">&gt;</span></span>org.apache.iotdb<span class="token tag"><span class="token tag"><span class="token punctuation">&lt;/</span>groupId</span><span class="token punctuation">&gt;</span></span>
      <span class="token tag"><span class="token tag"><span class="token punctuation">&lt;</span>artifactId</span><span class="token punctuation">&gt;</span></span>iotdb-thrift-cluster<span class="token tag"><span class="token tag"><span class="token punctuation">&lt;/</span>artifactId</span><span class="token punctuation">&gt;</span></span>
      <span class="token tag"><span class="token tag"><span class="token punctuation">&lt;</span>version</span><span class="token punctuation">&gt;</span></span>1.0.0<span class="token tag"><span class="token tag"><span class="token punctuation">&lt;/</span>version</span><span class="token punctuation">&gt;</span></span>
    <span class="token tag"><span class="token tag"><span class="token punctuation">&lt;/</span>dependency</span><span class="token punctuation">&gt;</span></span>
<span class="token tag"><span class="token tag"><span class="token punctuation">&lt;/</span>dependencies</span><span class="token punctuation">&gt;</span></span>
</code></pre><div class="line-numbers" aria-hidden="true"><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div></div></div><p>How to open a connection:</p><div class="language-java line-numbers-mode" data-ext="java"><pre class="language-java"><code><span class="token keyword">import</span> <span class="token import"><span class="token namespace">org<span class="token punctuation">.</span>apache<span class="token punctuation">.</span>thrift<span class="token punctuation">.</span>protocol<span class="token punctuation">.</span></span><span class="token class-name">TBinaryProtocol</span></span><span class="token punctuation">;</span>
<span class="token keyword">import</span> <span class="token import"><span class="token namespace">org<span class="token punctuation">.</span>apache<span class="token punctuation">.</span>thrift<span class="token punctuation">.</span>transport<span class="token punctuation">.</span></span><span class="token class-name">TSocket</span></span><span class="token punctuation">;</span>
<span class="token keyword">import</span> <span class="token import"><span class="token namespace">org<span class="token punctuation">.</span>apache<span class="token punctuation">.</span>thrift<span class="token punctuation">.</span>transport<span class="token punctuation">.</span></span><span class="token class-name">TTransport</span></span><span class="token punctuation">;</span>
<span class="token keyword">import</span> <span class="token import"><span class="token namespace">org<span class="token punctuation">.</span>apache<span class="token punctuation">.</span>thrift<span class="token punctuation">.</span>transport<span class="token punctuation">.</span></span><span class="token class-name">TTransportException</span></span><span class="token punctuation">;</span>
<span class="token keyword">import</span> <span class="token import"><span class="token namespace">org<span class="token punctuation">.</span>apache<span class="token punctuation">.</span>iotdb<span class="token punctuation">.</span>rpc<span class="token punctuation">.</span></span><span class="token class-name">RpcTransportFactory</span></span><span class="token punctuation">;</span>

<span class="token keyword">public</span> <span class="token keyword">class</span> <span class="token class-name">CluserInfoClient</span> <span class="token punctuation">{</span>
  <span class="token class-name">TTransport</span> transport<span class="token punctuation">;</span>
  <span class="token class-name">ClusterInfoService<span class="token punctuation">.</span>Client</span> client<span class="token punctuation">;</span>
  <span class="token keyword">public</span> <span class="token keyword">void</span> <span class="token function">connect</span><span class="token punctuation">(</span><span class="token punctuation">)</span> <span class="token punctuation">{</span>
    transport <span class="token operator">=</span>
            <span class="token class-name">RpcTransportFactory</span><span class="token punctuation">.</span><span class="token constant">INSTANCE</span><span class="token punctuation">.</span><span class="token function">getTransport</span><span class="token punctuation">(</span>
                    <span class="token keyword">new</span> <span class="token class-name">TSocket</span><span class="token punctuation">(</span>
                            <span class="token comment">// the RPC address</span>
                            <span class="token class-name">IoTDBDescriptor</span><span class="token punctuation">.</span><span class="token function">getInstance</span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token punctuation">.</span><span class="token function">getConfig</span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token punctuation">.</span><span class="token function">getRpcAddress</span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token punctuation">,</span>
                            <span class="token comment">// the RPC port</span>
                            <span class="token class-name">ClusterDescriptor</span><span class="token punctuation">.</span><span class="token function">getInstance</span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token punctuation">.</span><span class="token function">getConfig</span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token punctuation">.</span><span class="token function">getClusterRpcPort</span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token punctuation">)</span><span class="token punctuation">)</span><span class="token punctuation">;</span>
    <span class="token keyword">try</span> <span class="token punctuation">{</span>
      transport<span class="token punctuation">.</span><span class="token keyword">open</span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token punctuation">;</span>
    <span class="token punctuation">}</span> <span class="token keyword">catch</span> <span class="token punctuation">(</span><span class="token class-name">TTransportException</span> e<span class="token punctuation">)</span> <span class="token punctuation">{</span>
      <span class="token class-name">Assert</span><span class="token punctuation">.</span><span class="token function">fail</span><span class="token punctuation">(</span>e<span class="token punctuation">.</span><span class="token function">getMessage</span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token punctuation">)</span><span class="token punctuation">;</span>
    <span class="token punctuation">}</span>
    <span class="token comment">//get the client</span>
    client <span class="token operator">=</span> <span class="token keyword">new</span> <span class="token class-name">ClusterInfoService<span class="token punctuation">.</span>Client</span><span class="token punctuation">(</span><span class="token keyword">new</span> <span class="token class-name">TBinaryProtocol</span><span class="token punctuation">(</span>transport<span class="token punctuation">)</span><span class="token punctuation">)</span><span class="token punctuation">;</span>
  <span class="token punctuation">}</span>
  <span class="token keyword">public</span> <span class="token keyword">void</span> <span class="token function">close</span><span class="token punctuation">(</span><span class="token punctuation">)</span> <span class="token punctuation">{</span>
    transport<span class="token punctuation">.</span><span class="token function">close</span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token punctuation">;</span>
  <span class="token punctuation">}</span>
<span class="token punctuation">}</span>
</code></pre><div class="line-numbers" aria-hidden="true"><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div></div></div><p>APIs in <code>ClusterInfoService.Client</code>:</p><ul><li>Get the physical hash ring of the cluster:</li></ul><div class="language-java line-numbers-mode" data-ext="java"><pre class="language-java"><code>list<span class="token generics"><span class="token punctuation">&lt;</span><span class="token class-name">Node</span><span class="token punctuation">&gt;</span></span> <span class="token function">getRing</span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token punctuation">;</span>
</code></pre><div class="line-numbers" aria-hidden="true"><div class="line-number"></div></div></div><ul><li>Get data partition information of input path and time range:</li></ul><div class="language-java line-numbers-mode" data-ext="java"><pre class="language-java"><code><span class="token doc-comment comment">/**
 * <span class="token keyword">@param</span> <span class="token parameter">path</span> input path (should contains a database name as its prefix)
 * <span class="token keyword">@return</span> the data partition info. If the time range only covers one data partition, the the size
 * of the list is one.
 */</span>
list<span class="token generics"><span class="token punctuation">&lt;</span><span class="token class-name">DataPartitionEntry</span><span class="token punctuation">&gt;</span></span> <span class="token function">getDataPartition</span><span class="token punctuation">(</span><span class="token number">1</span><span class="token operator">:</span>string path<span class="token punctuation">,</span> <span class="token number">2</span><span class="token operator">:</span><span class="token keyword">long</span> startTime<span class="token punctuation">,</span> <span class="token number">3</span><span class="token operator">:</span><span class="token keyword">long</span> endTime<span class="token punctuation">)</span><span class="token punctuation">;</span>
</code></pre><div class="line-numbers" aria-hidden="true"><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div></div></div><ul><li>Get metadata partition information of input path:</li></ul><div class="language-java line-numbers-mode" data-ext="java"><pre class="language-java"><code><span class="token doc-comment comment">/**
 * <span class="token keyword">@param</span> <span class="token parameter">path</span> input path (should contains a database name as its prefix)
 * <span class="token keyword">@return</span> metadata partition information
 */</span>
list<span class="token generics"><span class="token punctuation">&lt;</span><span class="token class-name">Node</span><span class="token punctuation">&gt;</span></span> <span class="token function">getMetaPartition</span><span class="token punctuation">(</span><span class="token number">1</span><span class="token operator">:</span>string path<span class="token punctuation">)</span><span class="token punctuation">;</span>
</code></pre><div class="line-numbers" aria-hidden="true"><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div></div></div><ul><li>Get the status (alive or not) of all nodes:</li></ul><div class="language-java line-numbers-mode" data-ext="java"><pre class="language-java"><code><span class="token doc-comment comment">/**
 * <span class="token keyword">@return</span> key: node, value: live or not
 */</span>
map<span class="token generics"><span class="token punctuation">&lt;</span><span class="token class-name">Node</span><span class="token punctuation">,</span> bool<span class="token punctuation">&gt;</span></span> <span class="token function">getAllNodeStatus</span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token punctuation">;</span>
</code></pre><div class="line-numbers" aria-hidden="true"><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div></div></div><ul><li>get the raft group info (voteFor, term, etc..) of the connected node<br> (Notice that this API is rarely used by users):</li></ul><div class="language-java line-numbers-mode" data-ext="java"><pre class="language-java"><code><span class="token doc-comment comment">/**
 * <span class="token keyword">@return</span> A multi-line string with each line representing the total time consumption, invocation
 *     number, and average time consumption.
 */</span>
string <span class="token function">getInstrumentingInfo</span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token punctuation">;</span>
</code></pre><div class="line-numbers" aria-hidden="true"><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div></div></div>`,126);function h(b,f){const e=p("RouterLink");return c(),o("div",null,[l(`

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    to you under the Apache License, Version 2.0 (the
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    software distributed under the License is distributed on an
    "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
    KIND, either express or implied.  See the License for the
    specific language governing permissions and limitations
    under the License.

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