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eadd35f6d5
The recent documentation formatting changes introduced the navigation panel on the left. However, due to the length of the query options navigation title these could overlap with the documentation paragraphs. This commit removes the underscores from the navigation titles of the query options, so browsers can break them into multiple lines. Additionally, the "SET" and "Query Options for the SET Statement" pages are merged to save some more space for the query option navigation titles. Testing: - Built the documentation and tested manually Change-Id: Icec787d7a2af848aaaff65be2ecf311a5ce8fe7f Reviewed-on: http://gerrit.cloudera.org:8080/20556 Tested-by: Impala Public Jenkins <impala-public-jenkins@cloudera.com> Reviewed-by: Jason Fehr <jfehr@cloudera.com> Reviewed-by: Peter Rozsa <prozsa@cloudera.com> Reviewed-by: Tamas Mate <tmater@apache.org>
101 lines
2.9 KiB
XML
101 lines
2.9 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="parquet_read_page_index">
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<title>PARQUET_READ_PAGE_INDEX Query Option</title>
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<titlealts audience="PDF">
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<navtitle>PARQUET READ PAGE INDEX</navtitle>
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</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="Parquet"/>
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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>
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Use the <codeph>PARQUET_READ_PAGE_INDEX</codeph> query option to disable or enable using
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the Parquet page index during scans. The page index contains min/max statistics at the
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page-level granularity. It can be used to skip pages and rows that do not match the
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conditions in the <codeph>WHERE</codeph> clause.
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</p>
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<p>
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This option enables the same optimization as the <codeph>PARQUET_READ_STATISTICS</codeph>
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at the finer grained page level.
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</p>
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<p>
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Impala supports filtering based on Parquet statistics:
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</p>
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<ul>
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<li>
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Of the types: Boolean, Integer, Decimal, String, Timestamp
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</li>
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<li>
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For simple predicates of the forms: <codeph><slot> <op> <constant></codeph> or
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<codeph><constant> <op> <slot></codeph>, where <codeph><op></codeph> is LT,
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LE, GE, GT, and EQ
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</li>
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</ul>
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<p>
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The supported values for the query option are:
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<ul>
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<li>
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<codeph>true</codeph> (<codeph>1</codeph>): Read the page-level statistics from the
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Parquet page index during query processing and filter out pages based on the
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statistics.
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</li>
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<li>
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<codeph>false</codeph> (<codeph>0</codeph>): Do not use the Parquet page index.
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</li>
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<li>
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Any other values are treated as <codeph>false</codeph>.
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</li>
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</ul>
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</p>
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<p>
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<b>Type:</b> Boolean
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</p>
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<p>
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<b>Default:</b> <codeph>TRUE</codeph>
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</p>
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</conbody>
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</concept>
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