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8377b9949c
For this change to land in master, the audience="hidden" code review needs to be completed first. Otherwise, the doc build would still work but the audience="hidden" content would be visible rather than hidden as desired. Some work happening in parallel might introduce additional instances of audience="Cloudera". I suggest addressing those in a followup CR so this global change can land quickly. Since the changes apply across so many different files, but are so narrow in scope, I suggest that the way to validate (check that no extraneous changes were introduced accidentally) is to diff just the changed lines: git diff -U0 HEAD^ HEAD In patch set 2, I updated other topics marked audience="Cloudera" by CRs that were pushed in the meantime. Change-Id: Ic93d89da77e1f51bbf548a522d98d0c4e2fb31c8 Reviewed-on: http://gerrit.cloudera.org:8080/5613 Reviewed-by: John Russell <jrussell@cloudera.com> Tested-by: Impala Public Jenkins
68 lines
2.3 KiB
XML
68 lines
2.3 KiB
XML
<?xml version="1.0" encoding="UTF-8"?>
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<!--
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Licensed to the Apache Software Foundation (ASF) under one
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or more contributor license agreements. See the NOTICE file
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distributed with this work for additional information
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regarding copyright ownership. The ASF licenses this file
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to you under the Apache License, Version 2.0 (the
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"License"); you may not use this file except in compliance
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with the License. You may obtain a copy of the License at
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http://www.apache.org/licenses/LICENSE-2.0
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Unless required by applicable law or agreed to in writing,
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software distributed under the License is distributed on an
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"AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
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KIND, either express or implied. See the License for the
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specific language governing permissions and limitations
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under the License.
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-->
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<!DOCTYPE concept PUBLIC "-//OASIS//DTD DITA Concept//EN" "concept.dtd">
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<concept id="prefetch_mode" rev="2.6.0 IMPALA-3286">
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<title>PREFETCH_MODE Query Option (<keyword keyref="impala26"/> or higher only)</title>
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<titlealts audience="PDF"><navtitle>PREFETCH_MODE</navtitle></titlealts>
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<prolog>
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<metadata>
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<data name="Category" value="Impala"/>
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<data name="Category" value="Impala Query Options"/>
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<data name="Category" value="Performance"/>
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<data name="Category" value="Developers"/>
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<data name="Category" value="Data Analysts"/>
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</metadata>
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</prolog>
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<conbody>
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<p rev="2.6.0 IMPALA-3286">
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<indexterm audience="hidden">PREFETCH_MODE query option</indexterm>
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Determines whether the prefetching optimization is applied during
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join query processing.
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</p>
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<p>
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<b>Type:</b> numeric (0, 1)
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or corresponding mnemonic strings (<codeph>NONE</codeph>, <codeph>HT_BUCKET</codeph>).
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</p>
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<p>
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<b>Default:</b> 1 (equivalent to <codeph>HT_BUCKET</codeph>)
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</p>
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<p conref="../shared/impala_common.xml#common/added_in_260"/>
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<p conref="../shared/impala_common.xml#common/usage_notes_blurb"/>
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<p>
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The default mode is 1, which means that hash table buckets are
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prefetched during join query processing.
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</p>
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<p conref="../shared/impala_common.xml#common/related_info"/>
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<p>
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<xref href="impala_joins.xml#joins"/>,
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<xref href="impala_perf_joins.xml#perf_joins"/>.
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</p>
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</conbody>
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</concept>
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