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Lu, Huayi
a24ca60074
Reviewed-by: Hasko, Vladimir <vladimir.hasko@t-systems.com> Co-authored-by: Lu, Huayi <luhuayi@huawei.com> Co-committed-by: Lu, Huayi <luhuayi@huawei.com>
19 lines
1.8 KiB
HTML
19 lines
1.8 KiB
HTML
<a name="EN-US_TOPIC_0000001145894519"></a><a name="EN-US_TOPIC_0000001145894519"></a>
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<h1 class="topictitle1">Case: Adjusting the Partial Clustering Key</h1>
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<div id="body8662426"><div class="section" id="EN-US_TOPIC_0000001145894519__s1ba7e051a62b4550845416235527d90c"><h4 class="sectiontitle">Symptom</h4><p id="EN-US_TOPIC_0000001145894519__a3f336fa9fcf24701a9fc5e84978da6d9">Information on the EXPLAIN PERFORMANCE at a site is as follows: As shown in the red boxes, two performance bottlenecks are scan operations in a table.</p>
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<p id="EN-US_TOPIC_0000001145894519__p871713368174"><span><img id="EN-US_TOPIC_0000001145894519__image138043373174" src="figure/en-us_image_0000001145495125.png"></span></p>
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<p id="EN-US_TOPIC_0000001145894519__p4665321153419"></p>
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<div class="section" id="EN-US_TOPIC_0000001145894519__sc784c281b70c410ea0fe58fb832be9ad"><h4 class="sectiontitle">Optimization Analysis</h4><p id="EN-US_TOPIC_0000001145894519__a3513c8923cf14bb0bcb592f104bcce98">After further analysis, we found that the filter condition acct_id ='A012709548':: bpchar exists in the two tables.</p>
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<p id="EN-US_TOPIC_0000001145894519__a7a25c0eef857456cb65c97c4280e9cc1"><span><img id="EN-US_TOPIC_0000001145894519__i44d8e6b358384fccafc32813a8a21dda" src="figure/en-us_image_0000001099135098.png"></span></p>
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<p id="EN-US_TOPIC_0000001145894519__a35fb9c37283840b5a00173c1c7792cba">Try to add the partial clustering key in the acct_id column of the two tables, and run the <strong id="EN-US_TOPIC_0000001145894519__b84235270695932">VACUUM FULL</strong> statement to make the local clustering take effect. The table performance is improved.</p>
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<div class="parentlink"><strong>Parent topic:</strong> <a href="dws_04_0474.html">Optimization Cases</a></div>
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