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d484d2f684
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>
55 lines
2.4 KiB
XML
55 lines
2.4 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="perf_benchmarks">
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<title>Benchmarking Impala Queries</title>
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<titlealts audience="PDF"><navtitle>Benchmarking</navtitle></titlealts>
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<prolog>
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<metadata>
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<data name="Category" value="Performance"/>
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<data name="Category" value="Impala"/>
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<data name="Category" value="Querying"/>
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<data name="Category" value="Proof of Concept"/>
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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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Because Impala, like other Hadoop components, is designed to handle large data volumes in a distributed
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environment, conduct any performance tests using realistic data and cluster configurations. Use a multi-node
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cluster rather than a single node; run queries against tables containing terabytes of data rather than tens
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of gigabytes. The parallel processing techniques used by Impala are most appropriate for workloads that are
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beyond the capacity of a single server.
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</p>
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<p>
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When you run queries returning large numbers of rows, the CPU time to pretty-print the output can be
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substantial, giving an inaccurate measurement of the actual query time. Consider using the
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<codeph>-B</codeph> option on the <codeph>impala-shell</codeph> command to turn off the pretty-printing, and
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optionally the <codeph>-o</codeph> option to store query results in a file rather than printing to the
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screen. See <xref href="impala_shell_options.xml#shell_options"/> for details.
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</p>
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</conbody>
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</concept>
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