Files
impala/docs/topics/impala_num_scanner_threads.xml
Jim Apple d484d2f684 Add Apache license header to files in doc directory
This now gives a clean RAT check with bin/check-rat-report.py, which
is one way for the Impala community to check compliance with ASF rules
on intellectual property.

Change-Id: I2ad06435f84a65ba126759e42a18fdaf52cd7036
Reviewed-on: http://gerrit.cloudera.org:8080/5232
Reviewed-by: Jim Apple <jbapple-impala@apache.org>
Tested-by: Impala Public Jenkins
Reviewed-by: John Russell <jrussell@cloudera.com>
2016-12-02 23:54:32 +00:00

54 lines
1.9 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="num_scanner_threads">
<title>NUM_SCANNER_THREADS Query Option</title>
<titlealts audience="PDF"><navtitle>NUM_SCANNER_THREADS</navtitle></titlealts>
<prolog>
<metadata>
<data name="Category" value="Impala"/>
<data name="Category" value="Impala Query Options"/>
<data name="Category" value="Performance"/>
<data name="Category" value="Developers"/>
<data name="Category" value="Data Analysts"/>
</metadata>
</prolog>
<conbody>
<p>
<indexterm audience="Cloudera">NUM_SCANNER_THREADS query option</indexterm>
Maximum number of scanner threads (on each node) used for each query. By default, Impala uses as many cores
as are available (one thread per core). You might lower this value if queries are using excessive resources
on a busy cluster. Impala imposes a maximum value automatically, so a high value has no practical effect.
</p>
<p>
<b>Type:</b> numeric
</p>
<p>
<b>Default:</b> 0
</p>
</conbody>
</concept>