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<!DOCTYPE concept PUBLIC "-//OASIS//DTD DITA Concept//EN" "concept.dtd">
<concept id="FETCH_ROWS_TIMEOUT_MS">
<title>FETCH_ROWS_TIMEOUT_MS Query Option</title>
<titlealts audience="PDF">
<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"/>
<p>Use the <codeph>FETCH_ROWS_TIMEOUT_MS</codeph> query option to control
how long Impala waits for query results when clients fetch rows.</p>
<p> When this query option is set to <codeph>0</codeph>, fetch requests wait
<p>The timeout applies both when query result spooling is enabled and disabled:<ul>
<li>When result spooling is disabled (<codeph>SPOOL_QUERY_RESULTS =
FALSE</codeph>), the timeout controls how long a client waits for a
single row batch to be produced by the coordinator. </li>
<li>When result spooling is enabled ( (<codeph>SPOOL_QUERY_RESULTS =
TRUE</codeph>), a client can fetch multiple row batches at a time,
so this timeout controls the total time a client waits for row batches
to be produced.</li>
<p>The timeout also applies to fetch requests issued against queries in the
'RUNNING' state. A 'RUNNING' query has no rows available, so any fetch
request will wait until the query transitions to the 'FINISHED' state and
for it to fetch all requested rows. A query in the 'FINISHED' state means
that the rows are available to be fetched.</p>
<codeph>10000</codeph> (10 seconds)</p>
<p><b>Added in:</b>
<keyword keyref="impala34"/></p>
<p><b>Related information:</b>
<xref href="impala_max_result_spooling_mem.xml#MAX_RESULT_SPOOLING_MEM"/>,
/>, <xref href="impala_spool_query_results.xml#SPOOL_QUERY_RESULTS"/></p>