forked from docs/doc-exports
Yang, Tong
3f5759eed2
Reviewed-by: Hasko, Vladimir <vladimir.hasko@t-systems.com> Co-authored-by: Yang, Tong <yangtong2@huawei.com> Co-committed-by: Yang, Tong <yangtong2@huawei.com>
81 lines
4.4 KiB
HTML
81 lines
4.4 KiB
HTML
<a name="mrs_01_0982"></a><a name="mrs_01_0982"></a>
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<h1 class="topictitle1">Optimizing SQL Statements</h1>
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<div id="body8662426"><div class="section" id="mrs_01_0982__en-us_topic_0000001219149073_section54613993212"><h4 class="sectiontitle">Scenario</h4><p id="mrs_01_0982__en-us_topic_0000001219149073_p3461139163215">When SQL statements are executed on Hive, if the <span class="parmname" id="mrs_01_0982__en-us_topic_0000001219149073_p2195a583a20f4de89c794e8089af52da"><b>(a&b) or (a&c)</b></span> logic exists in the statements, you are advised to change the logic to <span class="parmname" id="mrs_01_0982__en-us_topic_0000001219149073_p20135311881549babc02a2f6bb15e8bc"><b>a & (b or c)</b></span>.</p>
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</div>
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<div class="section" id="mrs_01_0982__en-us_topic_0000001219149073_section54619912329"><h4 class="sectiontitle">Example</h4><p id="mrs_01_0982__en-us_topic_0000001219149073_p124611917324">If condition a is <span class="parmvalue" id="mrs_01_0982__en-us_topic_0000001219149073_p5eff0f20e43642dbaf429777f5716bf9"><b>p_partkey = l_partkey</b></span>, the statements before optimization are as follows:</p>
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<pre class="screen" id="mrs_01_0982__en-us_topic_0000001219149073_screen20461139153215">select
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sum(l_extendedprice* (1 - l_discount)) as revenue
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from
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lineitem,
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part
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where
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(
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<strong id="mrs_01_0982__en-us_topic_0000001219149073_b24613933211">p_partkey = l_partkey </strong>
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and p_brand = 'Brand#32'
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and p_container in ('SM CASE', 'SM BOX', 'SM PACK', 'SM PKG')
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and l_quantity >= 7 and l_quantity <= 7 + 10
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and p_size between 1 and 5
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and l_shipmode in ('AIR', 'AIR REG')
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and l_shipinstruct = 'DELIVER IN PERSON'
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)
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or
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( <strong id="mrs_01_0982__en-us_topic_0000001219149073_b74611297322">p_partkey = l_partkey</strong>
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and p_brand = 'Brand#35'
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and p_container in ('MED BAG', 'MED BOX', 'MED PKG', 'MED PACK')
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and l_quantity >= 15 and l_quantity <= 15 + 10
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and p_size between 1 and 10
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and l_shipmode in ('AIR', 'AIR REG')
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and l_shipinstruct = 'DELIVER IN PERSON'
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)
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or
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( <strong id="mrs_01_0982__en-us_topic_0000001219149073_b134629973216">p_partkey = l_partkey</strong>
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and p_brand = 'Brand#24'
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and p_container in ('LG CASE', 'LG BOX', 'LG PACK', 'LG PKG')
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and l_quantity >= 26 and l_quantity <= 26 + 10
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and p_size between 1 and 15
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and l_shipmode in ('AIR', 'AIR REG')
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and l_shipinstruct = 'DELIVER IN PERSON'
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)</pre>
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<p id="mrs_01_0982__en-us_topic_0000001219149073_p11462198321">The statements after optimization are as follows:</p>
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<pre class="screen" id="mrs_01_0982__en-us_topic_0000001219149073_screen1946213983214">select
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sum(l_extendedprice* (1 - l_discount)) as revenue
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from
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lineitem,
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part
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where <strong id="mrs_01_0982__en-us_topic_0000001219149073_b1146217983216"> p_partkey = l_partkey</strong> and
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((
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p_brand = 'Brand#32'
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and p_container in ('SM CASE', 'SM BOX', 'SM PACK', 'SM PKG')
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and l_quantity >= 7 and l_quantity <= 7 + 10
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and p_size between 1 and 5
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and l_shipmode in ('AIR', 'AIR REG')
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and l_shipinstruct = 'DELIVER IN PERSON'
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)
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or
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(
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p_brand = 'Brand#35'
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and p_container in ('MED BAG', 'MED BOX', 'MED PKG', 'MED PACK')
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and l_quantity >= 15 and l_quantity <= 15 + 10
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and p_size between 1 and 10
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and l_shipmode in ('AIR', 'AIR REG')
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and l_shipinstruct = 'DELIVER IN PERSON'
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)
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or
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(
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p_brand = 'Brand#24'
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and p_container in ('LG CASE', 'LG BOX', 'LG PACK', 'LG PKG')
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and l_quantity >= 26 and l_quantity <= 26 + 10
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and p_size between 1 and 15
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and l_shipmode in ('AIR', 'AIR REG')
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and l_shipinstruct = 'DELIVER IN PERSON'
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))</pre>
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</div>
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</div>
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<div>
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<div class="familylinks">
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<div class="parentlink"><strong>Parent topic:</strong> <a href="mrs_01_0977.html">Hive Performance Tuning</a></div>
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</div>
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</div>
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