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| <!DOCTYPE concept PUBLIC "-//OASIS//DTD DITA Concept//EN" "concept.dtd"> |
| <concept rev="2.12.0" id="exec_time_limit_s"> |
| |
| <title>EXEC_TIME_LIMIT_S Query Option (<keyword keyref="impala212_full"/> or higher only)</title> |
| |
| <titlealts audience="PDF"> |
| |
| <navtitle>EXEC_TIME_LIMIT_S</navtitle> |
| |
| </titlealts> |
| |
| <prolog> |
| <metadata> |
| <data name="Category" value="Impala"/> |
| <data name="Category" value="Impala Query Options"/> |
| <data name="Category" value="Querying"/> |
| <data name="Category" value="Developers"/> |
| <data name="Category" value="Data Analysts"/> |
| </metadata> |
| </prolog> |
| |
| <conbody> |
| |
| <p rev="2.12.0"> |
| The <codeph>EXEC_TIME_LIMIT_S</codeph> query option sets a time limit on query execution. |
| If a query is still executing when time limit expires, it is automatically canceled. The |
| option is intended to prevent runaway queries that execute for much longer than intended. |
| </p> |
| |
| <p> |
| For example, an Impala administrator could set a default value of |
| <codeph>EXEC_TIME_LIMIT_S=3600</codeph> for a resource pool to automatically kill queries |
| that execute for longer than one hour (see |
| <xref href="impala_admission.xml#admission_control"/> for information about default query |
| options). Then, if a user accidentally runs a large query that executes for more than one |
| hour, it will be automatically killed after the time limit expires to free up resources. |
| Users can override the default value per query or per session if they do not want the |
| default <codeph>EXEC_TIME_LIMIT_S</codeph> value to apply to a specific query or a |
| session. |
| </p> |
| |
| <note> |
| <p> |
| The time limit only starts once the query is executing. Time spent planning the query, |
| scheduling the query, or in admission control is not counted towards the execution time |
| limit. <codeph>SELECT</codeph> statements are eligible for automatic cancellation until |
| the client has fetched all result rows. DML queries are eligible for automatic |
| cancellation until the DML statement has finished. |
| </p> |
| </note> |
| |
| <p conref="../shared/impala_common.xml#common/syntax_blurb"/> |
| |
| <codeblock>SET EXEC_TIME_LIMIT_S=<varname>seconds</varname>;</codeblock> |
| |
| <p> |
| <b>Type:</b> numeric |
| </p> |
| |
| <p> |
| <b>Default:</b> 0 (no time limit ) |
| </p> |
| |
| <p conref="../shared/impala_common.xml#common/added_in_212"/> |
| |
| <p conref="../shared/impala_common.xml#common/related_info"/> |
| |
| <p> |
| <xref href="impala_timeouts.xml#timeouts"/> |
| </p> |
| |
| </conbody> |
| |
| </concept> |