forked from docs/doc-exports
Su, Xiaomeng
04d4597cf3
Reviewed-by: Pruthi, Vineet <vineet.pruthi@t-systems.com> Co-authored-by: Su, Xiaomeng <suxiaomeng1@huawei.com> Co-committed-by: Su, Xiaomeng <suxiaomeng1@huawei.com>
32 lines
3.3 KiB
HTML
32 lines
3.3 KiB
HTML
<a name="dli_08_0157"></a><a name="dli_08_0157"></a>
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<h1 class="topictitle1">CLUSTER BY</h1>
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<div id="body8662426"><div class="section" id="dli_08_0157__en-us_topic_0093946902_se885f70b54ad4ff88ab59de0bb4e04c9"><h4 class="sectiontitle">Function</h4><p id="dli_08_0157__en-us_topic_0093946902_a568e184967f546518eccf01b30d190a8">This statement is used to bucket a table and sort the table within buckets. </p>
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</div>
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<div class="section" id="dli_08_0157__en-us_topic_0093946902_s204d0cee1b3e41bf9935200d76bfb99a"><h4 class="sectiontitle">Syntax</h4><div class="codecoloring" codetype="Sql" id="dli_08_0157__screen06101251132517"><div class="highlight"><table class="highlighttable"><tr><td class="linenos"><div class="linenodiv"><pre><span class="normal">1</span>
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<span class="normal">2</span></pre></div></td><td class="code"><div><pre><span></span><span class="k">SELECT</span><span class="w"> </span><span class="n">attr_expr_list</span><span class="w"> </span><span class="k">FROM</span><span class="w"> </span><span class="n">table_reference</span>
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<span class="w"> </span><span class="k">CLUSTER</span><span class="w"> </span><span class="k">BY</span><span class="w"> </span><span class="n">col_name</span><span class="w"> </span><span class="p">[,</span><span class="n">col_name</span><span class="w"> </span><span class="p">,...];</span>
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</pre></div></td></tr></table></div>
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</div>
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<div class="section" id="dli_08_0157__en-us_topic_0093946902_see5a2a39486a48a2a8987177fd48c248"><h4 class="sectiontitle">Keyword</h4><p id="dli_08_0157__en-us_topic_0093946902_a857bdbfd7b404273be11aa59bbd81c52">CLUSTER BY: Buckets are created based on specified fields. Single fields and multiple fields are supported, and data is sorted in buckets.</p>
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</div>
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<div class="section" id="dli_08_0157__en-us_topic_0093946902_sca95f070aaa44db9a09b39876e7b4a92"><h4 class="sectiontitle">Precautions</h4><p id="dli_08_0157__en-us_topic_0093946902_a1d69c7a3245f40e68dbef3f6db64c961">The to-be-sorted table must exist. If this statement is used to sort a table that does not exist, an error is reported.</p>
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</div>
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<div class="section" id="dli_08_0157__en-us_topic_0093946902_sf0e42adecca54f12b1d078a6ab8beb40"><h4 class="sectiontitle">Example</h4><p id="dli_08_0157__en-us_topic_0093946902_a91b8a141c94047d8a37caddfc7403278">To bucket the <strong id="dli_08_0157__b16741771300">student</strong> table according to the <strong id="dli_08_0157__b6638181119300">score</strong> field and sort tables within buckets in descending order, run the following statement: </p>
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<div class="codecoloring" codetype="Sql" id="dli_08_0157__screen344872782617"><div class="highlight"><table class="highlighttable"><tr><td class="linenos"><div class="linenodiv"><pre><span class="normal">1</span>
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<span class="normal">2</span></pre></div></td><td class="code"><div><pre><span></span><span class="k">SELECT</span><span class="w"> </span><span class="o">*</span><span class="w"> </span><span class="k">FROM</span><span class="w"> </span><span class="n">student</span>
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<span class="w"> </span><span class="k">CLUSTER</span><span class="w"> </span><span class="k">BY</span><span class="w"> </span><span class="n">score</span><span class="p">;</span>
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</pre></div></td></tr></table></div>
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</div>
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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="dli_08_0154.html">Sorting</a></div>
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</div>
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</div>
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