11 lines
3.7 KiB
HTML
11 lines
3.7 KiB
HTML
<?xml version="1.0" encoding="UTF-8" standalone="no"?><!DOCTYPE html><html xmlns="http://www.w3.org/1999/xhtml" xmlns:epub="http://www.idpf.org/2007/ops" xmlns:m="http://www.w3.org/1998/Math/MathML" xmlns:pls="http://www.w3.org/2005/01/pronunciation-lexicon" xmlns:ssml="http://www.w3.org/2001/10/synthesis" xmlns:svg="http://www.w3.org/2000/svg"><head><title>Recommendations for Indexing Meta Data Tables</title><link rel="stylesheet" type="text/css" href="docbook-epub.css"/><meta name="generator" content="DocBook XSL Stylesheets V1.78.1"/><link rel="prev" href="apbs09.xhtml" title="International and Multi-byte Characters"/><link rel="next" href="apc.xhtml" title="Appendix C. Batch Processing and Transactions"/></head><body><header/><section class="section" title="Recommendations for Indexing Meta Data Tables" epub:type="division" id="recommendationsForIndexingMetaDataTables"><div class="titlepage"><div><div><h2 class="title" style="clear: both">Recommendations for Indexing Meta Data Tables</h2></div></div></div><p>Spring Batch provides DDL samples for the meta-data tables in the
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Core jar file for several common database platforms. Index declarations
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are not included in that DDL because there are too many variations in how
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users may want to index depending on their precise platform, local
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conventions and also the business requirements of how the jobs will be
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operated. The table below provides some indication as to which columns are
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going to be used in a WHERE clause by the Dao implementations provided by
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Spring Batch, and how frequently they might be used, so that individual
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projects can make up their own minds about indexing.</p><div class="table" id="d5e4771"><div class="table-title">Table B.1. Where clauses in SQL statements (excluding primary keys) and
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their approximate frequency of use.</div><div class="table-contents"><table style="border-collapse: collapse; border-top: 0.5pt solid ; border-bottom: 0.5pt solid ; border-left: 0.5pt solid ; border-right: 0.5pt solid ; "><colgroup><col/><col/><col/></colgroup><tbody><tr><td style="border-right: 0.5pt solid ; border-bottom: 0.5pt solid ; ">Default Table Name</td><td style="border-right: 0.5pt solid ; border-bottom: 0.5pt solid ; ">Where Clause</td><td style="border-bottom: 0.5pt solid ; ">Frequency</td></tr><tr><td style="border-right: 0.5pt solid ; border-bottom: 0.5pt solid ; ">BATCH_JOB_INSTANCE</td><td style="border-right: 0.5pt solid ; border-bottom: 0.5pt solid ; ">JOB_NAME = ? and JOB_KEY = ?</td><td style="border-bottom: 0.5pt solid ; ">Every time a job is launched</td></tr><tr><td style="border-right: 0.5pt solid ; border-bottom: 0.5pt solid ; ">BATCH_JOB_EXECUTION</td><td style="border-right: 0.5pt solid ; border-bottom: 0.5pt solid ; ">JOB_INSTANCE_ID = ?</td><td style="border-bottom: 0.5pt solid ; ">Every time a job is restarted</td></tr><tr><td style="border-right: 0.5pt solid ; border-bottom: 0.5pt solid ; ">BATCH_EXECUTION_CONTEXT</td><td style="border-right: 0.5pt solid ; border-bottom: 0.5pt solid ; ">EXECUTION_ID = ? and KEY_NAME = ?</td><td style="border-bottom: 0.5pt solid ; ">On commit interval, a.k.a. chunk</td></tr><tr><td style="border-right: 0.5pt solid ; border-bottom: 0.5pt solid ; ">BATCH_STEP_EXECUTION</td><td style="border-right: 0.5pt solid ; border-bottom: 0.5pt solid ; ">VERSION = ?</td><td style="border-bottom: 0.5pt solid ; ">On commit interval, a.k.a. chunk (and at start and end of
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step)</td></tr><tr><td style="border-right: 0.5pt solid ; ">BATCH_STEP_EXECUTION</td><td style="border-right: 0.5pt solid ; ">STEP_NAME = ? and JOB_EXECUTION_ID = ?</td><td>Before each step execution</td></tr></tbody></table></div></div></section><footer/></body></html> |