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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
70 lines
2.9 KiB
XML
70 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_annotate_strings_utf8" rev="2.6.0 IMPALA-2069">
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<title>PARQUET_ANNOTATE_STRINGS_UTF8 Query Option (<keyword keyref="impala26"/> or higher only)</title>
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<titlealts audience="PDF"><navtitle>PARQUET_ANNOTATE_STRINGS_UTF8</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="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 rev="2.6.0 IMPALA-2069">
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<indexterm audience="hidden">PARQUET_ANNOTATE_STRINGS_UTF8 query option</indexterm>
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Causes Impala <codeph>INSERT</codeph> and <codeph>CREATE TABLE AS SELECT</codeph> statements
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to write Parquet files that use the UTF-8 annotation for <codeph>STRING</codeph> columns.
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</p>
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<p conref="../shared/impala_common.xml#common/usage_notes_blurb"/>
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<p>
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By default, Impala represents a <codeph>STRING</codeph> column in Parquet as an unannotated binary field.
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</p>
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<p>
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Impala always uses the UTF-8 annotation when writing <codeph>CHAR</codeph> and <codeph>VARCHAR</codeph>
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columns to Parquet files. An alternative to using the query option is to cast <codeph>STRING</codeph>
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values to <codeph>VARCHAR</codeph>.
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</p>
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<p>
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This option is to help make Impala-written data more interoperable with other data processing engines.
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Impala itself currently does not support all operations on UTF-8 data.
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Although data processed by Impala is typically represented in ASCII, it is valid to designate the
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data as UTF-8 when storing on disk, because ASCII is a subset of UTF-8.
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</p>
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<p conref="../shared/impala_common.xml#common/type_boolean"/>
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<p conref="../shared/impala_common.xml#common/default_false_0"/>
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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/related_info"/>
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<p>
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<xref href="impala_parquet.xml#parquet"/>
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</p>
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</conbody>
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</concept>
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