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24" class="breadcrumbHomeIcon_YNFT"><path d="M10 19v-5h4v5c0 .55.45 1 1 1h3c.55 0 1-.45 1-1v-7h1.7c.46 0 .68-.57.33-.87L12.67 3.6c-.38-.34-.96-.34-1.34 0l-8.36 7.53c-.34.3-.13.87.33.87H5v7c0 .55.45 1 1 1h3c.55 0 1-.45 1-1z" fill="currentColor"></path></svg></a></li><li class="breadcrumbs__item"><span class="breadcrumbs__link">Querying</span><meta itemprop="position" content="1"></li><li class="breadcrumbs__item"><span class="breadcrumbs__link">Druid SQL</span><meta itemprop="position" content="2"></li><li itemscope="" itemprop="itemListElement" itemtype="https://schema.org/ListItem" class="breadcrumbs__item breadcrumbs__item--active"><span class="breadcrumbs__link" itemprop="name">SQL query context</span><meta itemprop="position" content="3"></li></ul></nav><div class="tocCollapsible_ETCw theme-doc-toc-mobile tocMobile_ITEo"><button type="button" class="clean-btn tocCollapsibleButton_TO0P">On this page</button></div><div class="theme-doc-markdown markdown"><header><h1>SQL query context</h1></header><div class="theme-admonition theme-admonition-info alert alert--info admonition_LlT9"><div class="admonitionHeading_tbUL"><span class="admonitionIcon_kALy"><svg viewBox="0 0 14 16"><path fill-rule="evenodd" d="M7 2.3c3.14 0 5.7 2.56 5.7 5.7s-2.56 5.7-5.7 5.7A5.71 5.71 0 0 1 1.3 8c0-3.14 2.56-5.7 5.7-5.7zM7 1C3.14 1 0 4.14 0 8s3.14 7 7 7 7-3.14 7-7-3.14-7-7-7zm1 3H6v5h2V4zm0 6H6v2h2v-2z"></path></svg></span>info</div><div class="admonitionContent_S0QG"><p> Apache Druid supports two query languages: Druid SQL and <a href="/docs/latest/querying/">native queries</a>. |
| This document describes the SQL language.</p></div></div><p>Druid supports query context parameters which affect <a href="/docs/latest/querying/sql">SQL query</a> planning. |
| See <a href="/docs/latest/querying/query-context">Query context</a> for general query context parameters for all query types.</p><h2 class="anchor anchorWithStickyNavbar_LWe7" id="sql-query-context-parameters">SQL query context parameters<a href="#sql-query-context-parameters" class="hash-link" aria-label="Direct link to SQL query context parameters" title="Direct link to SQL query context parameters"></a></h2><p>The following table lists query context parameters you can use to configure Druid SQL planning. |
| You can override a parameter's default value by setting a runtime property in the format <code>druid.query.default.context.{query_context_key}</code>. |
| For more information, see <a href="/docs/latest/configuration/#overriding-default-query-context-values">Overriding default query context values</a>.</p><table><thead><tr><th>Parameter</th><th>Description</th><th>Default value</th></tr></thead><tbody><tr><td><code>sqlQueryId</code></td><td>SQL query ID. For HTTP client, Druid returns it in the <code>X-Druid-SQL-Query-Id</code> header.<br><br>To specify a SQL query ID, use <code>sqlQueryId</code> instead of <a href="/docs/latest/querying/query-context"><code>queryId</code></a>. Setting <code>queryId</code> for a SQL request has no effect. All native queries underlying SQL use an auto-generated <code>queryId</code>.</td><td>auto-generated</td></tr><tr><td><code>sqlTimeZone</code></td><td>Time zone for a connection. For example, "America/Los_Angeles" or an offset like "-08:00". This parameter affects how time functions and timestamp literals behave.</td><td>UTC</td></tr><tr><td><code>sqlStringifyArrays</code></td><td>If <code>true</code>, Druid serializes result columns with array values as JSON strings in the response instead of arrays.</td><td><code>true</code>, except for JDBC connections, where it's always <code>false</code></td></tr><tr><td><code>useApproximateCountDistinct</code></td><td>Whether to use an approximate cardinality algorithm for <code>COUNT(DISTINCT foo)</code>.</td><td><code>true</code></td></tr><tr><td><code>useGroupingSetForExactDistinct</code></td><td>Whether to use grouping sets to execute queries with multiple exact distinct aggregations.</td><td><code>false</code></td></tr><tr><td><code>useApproximateTopN</code></td><td>If <code>true</code>, Druid converts SQL queries to approximate <a href="/docs/latest/querying/topnquery">TopN queries</a> wherever possible. If <code>false</code>, Druid uses exact <a href="/docs/latest/querying/groupbyquery">GroupBy queries</a> instead.</td><td><code>true</code></td></tr><tr><td><code>enableTimeBoundaryPlanning</code></td><td>If <code>true</code>, Druid converts SQL queries to <a href="/docs/latest/querying/timeboundaryquery">time boundary queries</a> wherever possible. Time boundary queries are very efficient for min-max calculation on the <code>__time</code> column in a datasource.</td><td><code>false</code></td></tr><tr><td><code>useNativeQueryExplain</code></td><td>If <code>true</code>, <code>EXPLAIN PLAN FOR</code> returns the explain plan as a JSON representation of equivalent native query, else it returns the original version of explain plan generated by Calcite.<br><br>This property is provided for backwards compatibility. We don't recommend setting this parameter unless your application depends on the older behavior.</td><td><code>true</code></td></tr><tr><td><code>sqlFinalizeOuterSketches</code></td><td>If <code>false</code> (default behavior in Druid 25.0.0 and later), <code>DS_HLL</code>, <code>DS_THETA</code>, and <code>DS_QUANTILES_SKETCH</code> return sketches in query results. If <code>true</code> (default behavior in Druid 24.0.1 and earlier), Druid finalizes sketches from these functions when they appear in query results.<br><br>This property is provided for backwards compatibility with behavior in Druid 24.0.1 and earlier. We don't recommend setting this parameter unless your application uses Druid 24.0.1 or earlier. Instead, use a function that doesn't return a sketch, such as <code>APPROX_COUNT_DISTINCT_DS_HLL</code>, <code>APPROX_COUNT_DISTINCT_DS_THETA</code>, <code>APPROX_QUANTILE_DS</code>, <code>DS_THETA_ESTIMATE</code>, or <code>DS_GET_QUANTILE</code>.</td><td><code>false</code></td></tr><tr><td><code>sqlUseBoundAndSelectors</code></td><td>If <code>false</code> (default behavior in Druid 27.0.0 and later), the SQL planner uses <a href="/docs/latest/querying/filters#equality-filter">equality</a>, <a href="/docs/latest/querying/filters#null-filter">null</a>, and <a href="/docs/latest/querying/filters#range-filter">range</a> filters instead of <a href="/docs/latest/querying/filters#selector-filter">selector</a> and <a href="/docs/latest/querying/filters#bound-filter">bounds</a>. For filtering <code>ARRAY</code> typed values, <code>sqlUseBoundAndSelectors</code> must be <code>false</code>.</td><td><code>false</code>.</td></tr><tr><td><code>sqlReverseLookup</code></td><td>Whether to consider the <a href="/docs/latest/querying/lookups#reverse-lookup">reverse-lookup rewrite</a> of the <code>LOOKUP</code> function during SQL planning.<br><br>Druid reverses calls to <code>LOOKUP</code> only when the number of matching keys is lower than both <code>inSubQueryThreshold</code> and <code>sqlReverseLookupThreshold</code>.</td><td><code>true</code></td></tr><tr><td><code>sqlReverseLookupThreshold</code></td><td>Maximum size of <code>IN</code> filter to create when applying a <a href="/docs/latest/querying/lookups#reverse-lookup">reverse-lookup rewrite</a>. If a <code>LOOKUP</code> call matches more keys than the specified threshold, it remains unchanged.<br><br>If <code>inSubQueryThreshold</code> is lower than <code>sqlReverseLookupThreshold</code>, Druid uses <code>inSubQueryThreshold</code> threshold instead.</td><td>10000</td></tr><tr><td><code>sqlPullUpLookup</code></td><td>Whether to consider the <a href="/docs/latest/querying/lookups#pull-up">pull-up rewrite</a> of the <code>LOOKUP</code> function during SQL planning.</td><td><code>true</code></td></tr><tr><td><code>enableJoinLeftTableScanDirect</code></td><td>This parameter applies to queries with joins. By default, when the left child is a simple scan with a filter, Druid runs the scan as a query, then joins it with the right child on the Broker. Setting this parameter to <code>true</code> overrides that behavior and pushes the join to the data servers instead. Even if a query doesn't explicitly include a join, this parameter may still apply since the SQL planner can translate the query into a join internally.</td><td><code>false</code></td></tr><tr><td><code>maxNumericInFilters</code></td><td>Max limit for the amount of numeric values that Druid can compare for a string type dimension when the entire SQL WHERE clause of a query translates only to an <a href="/docs/latest/querying/filters#or">OR</a> of <a href="/docs/latest/querying/filters#bound-filter">bound filter</a>. By default, Druid doesn't restrict the amount of numeric bound filters on string columns, although this situation may block other queries from running. Set this parameter to a smaller value to prevent Druid from running queries that have prohibitively long segment processing times. The optimal limit requires some trial and error. We recommend starting with 100. Users who submit a query that exceeds the limit of <code>maxNumericInFilters</code> should rewrite their queries to use strings in the <code>WHERE</code> clause instead of numbers. For example, <code>WHERE someString IN (‘123’, ‘456’)</code>. This value can't exceed the set system configuration <code>druid.sql.planner.maxNumericInFilters</code>. If <code>druid.sql.planner.maxNumericInFilters</code> isn't set explicitly, Druid ignores this value.</td><td><code>-1</code></td></tr><tr><td><code>inFunctionThreshold</code></td><td>At or beyond this threshold number of values, Druid converts SQL <code>IN</code> to <a href="/docs/latest/querying/sql-functions#scalar_in_array"><code>SCALAR_IN_ARRAY</code></a>. A threshold of 0 forces this conversion in all cases. A threshold of <code>Integer.MAX_VALUE</code> disables this conversion. The converted function is eligible for fewer planning-time optimizations, which speeds up planning, but may prevent certain planning-time optimizations.</td><td><code>100</code></td></tr><tr><td><code>inFunctionExprThreshold</code></td><td>At or beyond this threshold number of values, SQL <code>IN</code> is eligible for execution using the native function <code>scalar_in_array</code> rather than an <code>|<!-- -->|</code> of <code>==</code>, even if the number of values is below <code>inFunctionThreshold</code>. This property only affects translation of SQL <code>IN</code> to a <a href="/docs/latest/querying/math-expr">native expression</a>. It doesn't affect translation of SQL <code>IN</code> to a <a href="/docs/latest/querying/filters">native filter</a>. This property is provided for backwards compatibility purposes, and may be removed in a future release.</td><td><code>2</code></td></tr><tr><td><code>inSubQueryThreshold</code></td><td>At or beyond this threshold number of values, Druid converts SQL <code>IN</code> to <code>JOIN</code> on an inline table. <code>inFunctionThreshold</code> takes priority over this setting. A threshold of 0 forces usage of an inline table in all cases where the size of a SQL <code>IN</code> is larger than <code>inFunctionThreshold</code>. A threshold of <code>2147483647</code> disables the rewrite of SQL <code>IN</code> to <code>JOIN</code>.</td><td><code>2147483647</code></td></tr></tbody></table><h2 class="anchor anchorWithStickyNavbar_LWe7" id="set-the-query-context">Set the query context<a href="#set-the-query-context" class="hash-link" aria-label="Direct link to Set the query context" title="Direct link to Set the query context"></a></h2><p>You can configure query context parameters in the <code>context</code> object of the <a href="/docs/latest/api-reference/sql-api">JSON API</a> or as a <a href="/docs/latest/api-reference/sql-jdbc">JDBC connection properties object</a>.</p><p>The following example shows how to set a query context parameter using the JSON API:</p><div class="codeBlockContainer_Ckt0 theme-code-block" style="--prism-color:#bfc7d5;--prism-background-color:#292d3e"><div class="codeBlockContent_biex"><pre tabindex="0" class="prism-code language-text codeBlock_bY9V thin-scrollbar"><code class="codeBlockLines_e6Vv"><span class="token-line" style="color:#bfc7d5"><span class="token plain">{</span><br></span><span class="token-line" style="color:#bfc7d5"><span class="token plain"> "query" : "SELECT COUNT(*) FROM data_source WHERE foo = 'bar' AND __time > TIMESTAMP '2000-01-01 00:00:00'",</span><br></span><span class="token-line" style="color:#bfc7d5"><span class="token plain"> "context" : {</span><br></span><span class="token-line" style="color:#bfc7d5"><span class="token plain"> "sqlTimeZone" : "America/Los_Angeles"</span><br></span><span class="token-line" style="color:#bfc7d5"><span class="token plain"> }</span><br></span><span class="token-line" style="color:#bfc7d5"><span class="token plain">}</span><br></span></code></pre><div class="buttonGroup__atx"><button type="button" aria-label="Copy code to clipboard" title="Copy" class="clean-btn"><span class="copyButtonIcons_eSgA" aria-hidden="true"><svg viewBox="0 0 24 24" class="copyButtonIcon_y97N"><path fill="currentColor" d="M19,21H8V7H19M19,5H8A2,2 0 0,0 6,7V21A2,2 0 0,0 8,23H19A2,2 0 0,0 21,21V7A2,2 0 0,0 19,5M16,1H4A2,2 0 0,0 2,3V17H4V3H16V1Z"></path></svg><svg viewBox="0 0 24 24" class="copyButtonSuccessIcon_LjdS"><path fill="currentColor" d="M21,7L9,19L3.5,13.5L4.91,12.09L9,16.17L19.59,5.59L21,7Z"></path></svg></span></button></div></div></div><p>The following example shows how to set query context parameters using JDBC:</p><div class="language-java codeBlockContainer_Ckt0 theme-code-block" style="--prism-color:#bfc7d5;--prism-background-color:#292d3e"><div class="codeBlockContent_biex"><pre tabindex="0" class="prism-code language-java codeBlock_bY9V thin-scrollbar"><code class="codeBlockLines_e6Vv"><span class="token-line" style="color:#bfc7d5"><span class="token plain">String url = "jdbc:avatica:remote:url=http://localhost:8082/druid/v2/sql/avatica/";</span><br></span><span class="token-line" style="color:#bfc7d5"><span class="token plain" style="display:inline-block"></span><br></span><span class="token-line" style="color:#bfc7d5"><span class="token plain">// Set any query context parameters you need here.</span><br></span><span class="token-line" style="color:#bfc7d5"><span class="token plain">Properties connectionProperties = new Properties();</span><br></span><span class="token-line" style="color:#bfc7d5"><span class="token plain">connectionProperties.setProperty("sqlTimeZone", "America/Los_Angeles");</span><br></span><span class="token-line" style="color:#bfc7d5"><span class="token plain">connectionProperties.setProperty("useCache", "false");</span><br></span><span class="token-line" style="color:#bfc7d5"><span class="token plain" style="display:inline-block"></span><br></span><span class="token-line" style="color:#bfc7d5"><span class="token plain">try (Connection connection = DriverManager.getConnection(url, connectionProperties)) {</span><br></span><span class="token-line" style="color:#bfc7d5"><span class="token plain"> // create and execute statements, process result sets, etc</span><br></span><span class="token-line" style="color:#bfc7d5"><span class="token plain">}</span><br></span></code></pre><div class="buttonGroup__atx"><button type="button" aria-label="Copy code to clipboard" title="Copy" class="clean-btn"><span class="copyButtonIcons_eSgA" aria-hidden="true"><svg viewBox="0 0 24 24" class="copyButtonIcon_y97N"><path fill="currentColor" d="M19,21H8V7H19M19,5H8A2,2 0 0,0 6,7V21A2,2 0 0,0 8,23H19A2,2 0 0,0 21,21V7A2,2 0 0,0 19,5M16,1H4A2,2 0 0,0 2,3V17H4V3H16V1Z"></path></svg><svg viewBox="0 0 24 24" class="copyButtonSuccessIcon_LjdS"><path fill="currentColor" d="M21,7L9,19L3.5,13.5L4.91,12.09L9,16.17L19.59,5.59L21,7Z"></path></svg></span></button></div></div></div></div></article><nav class="pagination-nav docusaurus-mt-lg" aria-label="Docs pages"><a class="pagination-nav__link pagination-nav__link--prev" href="/docs/latest/querying/sql-json-functions"><div class="pagination-nav__sublabel">Previous</div><div class="pagination-nav__label">JSON functions</div></a><a class="pagination-nav__link pagination-nav__link--next" href="/docs/latest/querying/sql-metadata-tables"><div class="pagination-nav__sublabel">Next</div><div class="pagination-nav__label">SQL metadata tables</div></a></nav></div></div><div class="col col--3"><div class="tableOfContents_bqdL thin-scrollbar theme-doc-toc-desktop"><ul class="table-of-contents table-of-contents__left-border"><li><a href="#sql-query-context-parameters" class="table-of-contents__link toc-highlight">SQL query context parameters</a></li><li><a href="#set-the-query-context" class="table-of-contents__link toc-highlight">Set the query context</a></li></ul></div></div></div></div></main></div></div><footer class="footer"><div class="container container-fluid"><div class="footer__bottom text--center"><div class="margin-bottom--sm"><img src="/img/favicon.png" class="themedImage_ToTc themedImage--light_HNdA 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