youjiageng1/doc-exports
1
0
Fork 0
forked from laiweijian4/doc-exports
Code Pull Requests Activity
doc-exports/docs/dli/sqlreference/dli_08_0343.html
Su, Xiaomeng 04d4597cf3 dli_sqlreference_0511_version 
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>
2023-11-02 14:34:08 +00:00

77 lines
12 KiB
HTML
Raw Blame History

<a name="dli_08_0343"></a><a name="dli_08_0343"></a>
<h1 class="topictitle1">Deleting Partitions by Specifying Filter Criteria (Only OBS Tables Supported)</h1>
<div id="body0000001134396418"><div class="section" id="dli_08_0343__en-us_topic_0114776177_en-us_topic_0093946793_see77d47bd5ee4527b743ba74f2f8de11"><h4 class="sectiontitle">Function</h4><p id="dli_08_0343__en-us_topic_0114776177_en-us_topic_0093946793_a56c2c81b26f1481c8c3f5e2aa2e3e541">This statement is used to delete one or more partitions based on specified conditions.</p>
</div>
<div class="section" id="dli_08_0343__en-us_topic_0114776177_en-us_topic_0093946793_sa2e42a3b9c40499d8aece88e300172e2"><h4 class="sectiontitle">Precautions</h4><ul id="dli_08_0343__en-us_topic_0114776177_en-us_topic_0093946793_ueef317bd7b7d4848b71d76390b8e3a60"><li id="dli_08_0343__li6647606105"><strong id="dli_08_0343__b182517113810">This statement is used for OBS table operations only.</strong></li><li id="dli_08_0343__en-us_topic_0114776177_en-us_topic_0093946793_l83f3cefa18f84ac88190411ea31bd488">The table in which partitions are to be deleted must exist. Otherwise, an error is reported.</li><li id="dli_08_0343__en-us_topic_0114776177_en-us_topic_0093946793_l9d84b14aa0b049908b6b0b24edb3094f">The to-be-deleted partition must exist. Otherwise, an error is reported. To avoid this error, add <strong id="dli_08_0343__b75091715112815">IF EXISTS</strong> in this statement.</li></ul>
</div>
<div class="section" id="dli_08_0343__en-us_topic_0114776177_en-us_topic_0093946793_sdbfe5a0630ef4b47aea744c8c3d7fa27"><h4 class="sectiontitle">Syntax</h4><div class="codecoloring" codetype="Sql" id="dli_08_0343__en-us_topic_0114776177_screen797416436315"><div class="highlight"><table class="highlighttable"><tr><td class="linenos"><div class="linenodiv"><pre><span class="normal">1</span>
<span class="normal">2</span>
<span class="normal">3</span></pre></div></td><td class="code"><div><pre><span></span><span class="k">ALTER</span><span class="w"> </span><span class="k">TABLE</span><span class="w"> </span><span class="p">[</span><span class="n">db_name</span><span class="p">.]</span><span class="k">table_name</span>
<span class="w"> </span><span class="k">DROP</span><span class="w"> </span><span class="p">[</span><span class="k">IF</span><span class="w"> </span><span class="k">EXISTS</span><span class="p">]</span>
<span class="w"> </span><span class="n">PARTITIONS</span><span class="w"> </span><span class="n">partition_filtercondition</span><span class="p">;</span>
</pre></div></td></tr></table></div>
</div>
</div>
<div class="section" id="dli_08_0343__en-us_topic_0114776176_en-us_topic_0093946763_s4722556def8545d097cf905b9261c45d"><h4 class="sectiontitle">Keyword</h4><ul id="dli_08_0343__ul48718578292"><li id="dli_08_0343__li4871155782917">DROP: deletes specified partitions.</li><li id="dli_08_0343__li1287105772917">IF EXISTS: Partitions to be deleted must exist. Otherwise, an error is reported.</li><li id="dli_08_0343__li1342780414">PARTITIONS: specifies partitions meeting the conditions</li></ul>
</div>
<div class="section" id="dli_08_0343__en-us_topic_0114776177_section860512913615"><h4 class="sectiontitle">Parameters</h4>
<div class="tablenoborder"><table cellpadding="4" cellspacing="0" summary="" id="dli_08_0343__en-us_topic_0114776177_en-us_topic_0103084434_t2fa8597e0dde4884bd6412ac207ebea8" frame="border" border="1" rules="all"><caption><b>Table 1 </b>Parameter description</caption><thead align="left"><tr id="dli_08_0343__en-us_topic_0114776177_en-us_topic_0103084434_r16c75fd8fdbf41c79f9aee82b032351c"><th align="left" class="cellrowborder" valign="top" width="20.52%" id="mcps1.3.5.2.2.3.1.1"><p id="dli_08_0343__en-us_topic_0114776177_en-us_topic_0103084434_a9dd69379a3f54904a9c510fb817659ad">Parameter</p>
</th>
<th align="left" class="cellrowborder" valign="top" width="79.47999999999999%" id="mcps1.3.5.2.2.3.1.2"><p id="dli_08_0343__en-us_topic_0114776177_en-us_topic_0103084434_a7ede0d62539542baa7e367cf902bf2b2">Description</p>
</th>
</tr>
</thead>
<tbody><tr id="dli_08_0343__en-us_topic_0114776177_en-us_topic_0103084434_r8ab7399810eb42b7abf51ae705c6cf83"><td class="cellrowborder" valign="top" width="20.52%" headers="mcps1.3.5.2.2.3.1.1 "><p id="dli_08_0343__en-us_topic_0114776177_en-us_topic_0103084434_a1cdeda4790a8452d8619c797147bf9cf">db_name</p>
</td>
<td class="cellrowborder" valign="top" width="79.47999999999999%" headers="mcps1.3.5.2.2.3.1.2 "><p id="dli_08_0343__en-us_topic_0114776177_en-us_topic_0103084434_p4729195274115">Database name that contains letters, digits, and underscores (_). It cannot contain only digits or start with an underscore (_).</p>
</td>
</tr>
<tr id="dli_08_0343__en-us_topic_0114776177_en-us_topic_0103084434_r36540eab62c64ec4babb57549d5776e7"><td class="cellrowborder" valign="top" width="20.52%" headers="mcps1.3.5.2.2.3.1.1 "><p id="dli_08_0343__en-us_topic_0114776177_en-us_topic_0103084434_aa0912c807a254106a3a033e8ccb9e95e">table_name</p>
</td>
<td class="cellrowborder" valign="top" width="79.47999999999999%" headers="mcps1.3.5.2.2.3.1.2 "><p id="dli_08_0343__en-us_topic_0114776177_en-us_topic_0103084434_ae05b93123b5b41ff91b2875680e77dac">Table name of a database that contains letters, digits, and underscores (_). It cannot contain only digits or start with an underscore (_). The matching rule is <strong id="dli_08_0343__b1016516214225">^(?!_)(?![0-9]+$)[A-Za-z0-9_$]*$</strong>. If special characters are required, use single quotation marks ('') to enclose them.</p>
<p id="dli_08_0343__p16154123811412"><strong id="dli_08_0343__b57996181680">This statement is used for OBS table operations.</strong></p>
</td>
</tr>
<tr id="dli_08_0343__en-us_topic_0114776177_en-us_topic_0103084434_r360f5784fda14ac1b1a3ff638aaa5b26"><td class="cellrowborder" valign="top" width="20.52%" headers="mcps1.3.5.2.2.3.1.1 "><p id="dli_08_0343__p43818182314">partition_filtercondition</p>
</td>
<td class="cellrowborder" valign="top" width="79.47999999999999%" headers="mcps1.3.5.2.2.3.1.2 "><p id="dli_08_0343__en-us_topic_0114776177_en-us_topic_0103084434_p3787647395919">Condition used to search partitions to be deleted. The format is as follows:</p>
<ul id="dli_08_0343__ul93501094324"><li id="dli_08_0343__li1735020903215"><em id="dli_08_0343__i447819182517">Partition column name</em> <a href="dli_08_0061.html#dli_08_0061__en-us_topic_0093946932_t34b3b699258a401085f3c3b3ad1a3717">Operator</a> <em id="dli_08_0343__i15685102017264">Value to compare</em><p id="dli_08_0343__p18125223104115">Example: start_date &lt; '201911'</p>
</li><li id="dli_08_0343__li1322893319389">&lt;partition_filtercondition1&gt; AND|OR &lt;partition_filtercondition2&gt;<p id="dli_08_0343__p15731338433"><a name="dli_08_0343__li1322893319389"></a><a name="li1322893319389"></a>Example: start_date &lt; '201911' OR start_date &gt;= '202006'</p>
</li><li id="dli_08_0343__li6882238133913">(&lt;partition_filtercondition1&gt;) [,partitions (&lt;partition_filtercondition2&gt;), ...]<p id="dli_08_0343__p37221634436"><a name="dli_08_0343__li6882238133913"></a><a name="li6882238133913"></a>Example: (start_date &lt;&gt; '202007'), partitions(start_date &lt; '201912')</p>
</li></ul>
</td>
</tr>
</tbody>
</table>
</div>
</div>
<div class="section" id="dli_08_0343__en-us_topic_0114776177_en-us_topic_0093946793_sbd247a258fdd490a988c980dd33504e6"><h4 class="sectiontitle">Example</h4><p id="dli_08_0343__en-us_topic_0114776177_en-us_topic_0093946793_a07d135d6e32641898620af93b0a267c2">You can run the following statements to delete partitions of the <strong id="dli_08_0343__b118135548367">student</strong> table using different conditions:</p>
<div class="codecoloring" codetype="Sql" id="dli_08_0343__en-us_topic_0114776177_screen361074812321"><div class="highlight"><table class="highlighttable"><tr><td class="linenos"><div class="linenodiv"><pre><span class="normal">1</span>
<span class="normal">2</span>
<span class="normal">3</span>
<span class="normal">4</span>
<span class="normal">5</span>
<span class="normal">6</span>
<span class="normal">7</span>
<span class="normal">8</span></pre></div></td><td class="code"><div><pre><span></span><span class="k">alter</span><span class="w"> </span><span class="k">table</span><span class="w"> </span><span class="n">student</span><span class="w"> </span><span class="k">drop</span><span class="w"> </span><span class="n">partitions</span><span class="p">(</span><span class="n">start_date</span><span class="w"> </span><span class="o">&lt;</span><span class="w"> </span><span class="s1">'201911'</span><span class="p">);</span>
<span class="k">alter</span><span class="w"> </span><span class="k">table</span><span class="w"> </span><span class="n">student</span><span class="w"> </span><span class="k">drop</span><span class="w"> </span><span class="n">partitions</span><span class="p">(</span><span class="n">start_date</span><span class="w"> </span><span class="o">&gt;=</span><span class="w"> </span><span class="s1">'202007'</span><span class="p">);</span>
<span class="k">alter</span><span class="w"> </span><span class="k">table</span><span class="w"> </span><span class="n">student</span><span class="w"> </span><span class="k">drop</span><span class="w"> </span><span class="n">partitions</span><span class="p">(</span><span class="n">start_date</span><span class="w"> </span><span class="k">BETWEEN</span><span class="w"> </span><span class="s1">'202001'</span><span class="w"> </span><span class="k">AND</span><span class="w"> </span><span class="s1">'202007'</span><span class="p">);</span>
<span class="k">alter</span><span class="w"> </span><span class="k">table</span><span class="w"> </span><span class="n">student</span><span class="w"> </span><span class="k">drop</span><span class="w"> </span><span class="n">partitions</span><span class="p">(</span><span class="n">start_date</span><span class="w"> </span><span class="o">&lt;</span><span class="w"> </span><span class="s1">'201912'</span><span class="w"> </span><span class="k">OR</span><span class="w"> </span><span class="n">start_date</span><span class="w"> </span><span class="o">&gt;=</span><span class="w"> </span><span class="s1">'202006'</span><span class="p">);</span>
<span class="k">alter</span><span class="w"> </span><span class="k">table</span><span class="w"> </span><span class="n">student</span><span class="w"> </span><span class="k">drop</span><span class="w"> </span><span class="n">partitions</span><span class="p">(</span><span class="n">start_date</span><span class="w"> </span><span class="o">&gt;</span><span class="w"> </span><span class="s1">'201912'</span><span class="w"> </span><span class="k">AND</span><span class="w"> </span><span class="n">start_date</span><span class="w"> </span><span class="o">&lt;=</span><span class="w"> </span><span class="s1">'202004'</span><span class="p">);</span>
<span class="k">alter</span><span class="w"> </span><span class="k">table</span><span class="w"> </span><span class="n">student</span><span class="w"> </span><span class="k">drop</span><span class="w"> </span><span class="n">partitions</span><span class="p">(</span><span class="n">start_date</span><span class="w"> </span><span class="o">!=</span><span class="w"> </span><span class="s1">'202007'</span><span class="p">);</span>
<span class="k">alter</span><span class="w"> </span><span class="k">table</span><span class="w"> </span><span class="n">student</span><span class="w"> </span><span class="k">drop</span><span class="w"> </span><span class="n">partitions</span><span class="p">(</span><span class="n">start_date</span><span class="w"> </span><span class="o">&lt;&gt;</span><span class="w"> </span><span class="s1">'202007'</span><span class="p">);</span>
<span class="k">alter</span><span class="w"> </span><span class="k">table</span><span class="w"> </span><span class="n">student</span><span class="w"> </span><span class="k">drop</span><span class="w"> </span><span class="n">partitions</span><span class="p">(</span><span class="n">start_date</span><span class="w"> </span><span class="o">&lt;&gt;</span><span class="w"> </span><span class="s1">'202007'</span><span class="p">),</span><span class="w"> </span><span class="n">partitions</span><span class="p">(</span><span class="n">start_date</span><span class="w"> </span><span class="o">&lt;</span><span class="w"> </span><span class="s1">'201912'</span><span class="p">);</span>
</pre></div></td></tr></table></div>
</div>
</div>
</div>
<div>
<div class="familylinks">
<div class="parentlink"><strong>Parent topic:</strong> <a href="dli_08_0080.html">Syntax for Partitioning a Table</a></div>
</div>
</div>
View Git Blame Copy Permalink