mirror of
https://github.com/apache/impala.git
synced 2026-01-16 18:00:39 -05:00
c4874d9a94
Change-Id: I78bfceb225d25078c54c1ed8f88ca250ef42dafe Reviewed-on: http://gerrit.cloudera.org:8080/14314 Reviewed-by: Sahil Takiar <stakiar@cloudera.com> Tested-by: Impala Public Jenkins <impala-public-jenkins@cloudera.com>
67 lines
3.0 KiB
XML
67 lines
3.0 KiB
XML
<?xml version="1.0" encoding="UTF-8"?>
|
|
<!--
|
|
Licensed to the Apache Software Foundation (ASF) under one
|
|
or more contributor license agreements. See the NOTICE file
|
|
distributed with this work for additional information
|
|
regarding copyright ownership. The ASF licenses this file
|
|
to you under the Apache License, Version 2.0 (the
|
|
"License"); you may not use this file except in compliance
|
|
with the License. You may obtain a copy of the License at
|
|
|
|
http://www.apache.org/licenses/LICENSE-2.0
|
|
|
|
Unless required by applicable law or agreed to in writing,
|
|
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.
|
|
-->
|
|
<!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">
|
|
<navtitle>FETCH_ROWS_TIMEOUT_MS</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>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
|
|
indefinitely.</p>
|
|
<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>
|
|
</ul></p>
|
|
<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>
|
|
<p><b>Type:</b>
|
|
<codeph>INT</codeph></p>
|
|
<p><b>Default:</b>
|
|
<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_max_spilled_result_spooling_mem.xml#MAX_SPILLED_RESULT_SPOOLING_MEM"
|
|
/>, <xref href="impala_spool_query_results.xml#SPOOL_QUERY_RESULTS"/></p>
|
|
</conbody>
|
|
</concept>
|