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 <div class="header">
   <div class="headertitle">
 <div class="title">Quantile<div class="ingroups"><a class="el" href="group__grp__early__stage.html">Early Stage Development</a></div></div>  </div>
 </div><!--header-->
 <div class="contents">
 <dl class="section warning"><dt>Warning</dt><dd><em> This MADlib method is still in early stage development. There may be some issues that will be addressed in a future version. Interface and implementation is subject to change. </em></dd></dl>
 <dl class="section user"><dt>About</dt><dd>This function computes the specified quantile value. It reads the name of the table, the specific column, and computes the quantile value based on the fraction specified as the third argument.</dd></dl>
 <p>For an implementation of quantile using sketches, check out the <a class="el" href="sketch_8sql__in.html#a2f2ab2fe3244515f5f73d49690e73b39" title="cmsketch_centile is a scalar UDF to compute a centile value from a cmsketch. Takes the results of the...">cmsketch_centile()</a> aggregate in the <a class="el" href="group__grp__countmin.html">CountMin (Cormode-Muthukrishnan)</a> module.</p>
 <dl class="section user"><dt>Implementation Notes</dt><dd>There are two implementations of quantile available depending on the size of the table. <code>quantile</code> is best used for small tables (e.g. less than 5000 rows, with 1-2 columns in total). For larger tables, consider using <code>quantile_big</code> instead.</dd></dl>
 <dl class="section user"><dt>Usage</dt><dd><pre>SELECT * FROM quantile( '<em>table_name</em>', '<em>col_name</em>', <em>quantile</em>);</pre> <pre>SELECT * FROM quantile_big( '<em>table_name</em>', '<em>col_name</em>', <em>quantile</em>);</pre></dd></dl>
 <dl class="section user"><dt>Examples</dt><dd><ol type="1">
 <li>Prepare some input: <pre class="fragment">sql&gt; CREATE TABLE tab1 AS SELECT generate_series( 1,1000) as col1;
 </pre></li>
 <li>Run the <a class="el" href="quantile_8sql__in.html#a6955e44659a0817803ab7a11a9a7e8a5" title="Computes quantile. ">quantile()</a> function:<br/>
  <pre class="fragment">sql&gt; SELECT quantile( 'tab1', 'col1', .3);

    quantile
 --------------
  301.48046875
 (1 row)
 </pre></li>
 </ol>
 </dd></dl>
 <dl class="section see"><dt>See Also</dt><dd>File <a class="el" href="quantile_8sql__in.html" title="SQL function for Quantile. ">quantile.sql_in</a> documenting the SQL function.<br/>
 <br/>
  Module <a class="el" href="group__grp__countmin.html">CountMin (Cormode-Muthukrishnan)</a> for an approximate <a class="el" href="quantile_8sql__in.html#a6955e44659a0817803ab7a11a9a7e8a5" title="Computes quantile. ">quantile</a> implementation. </dd></dl>
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	<span id="projectnumber">1.2</span> <span style="font-size:10pt; font-style:italic"><a href="../latest/./group__grp__quantile.html"> A newer version is available</a></span>
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	<div class="header">
	<div class="headertitle">
	<div class="title">Quantile<div class="ingroups"><a class="el" href="group__grp__early__stage.html">Early Stage Development</a></div></div> </div>
	</div><!--header-->
	<div class="contents">
	<dl class="section warning"><dt>Warning</dt><dd><em> This MADlib method is still in early stage development. There may be some issues that will be addressed in a future version. Interface and implementation is subject to change. </em></dd></dl>
	<dl class="section user"><dt>About</dt><dd>This function computes the specified quantile value. It reads the name of the table, the specific column, and computes the quantile value based on the fraction specified as the third argument.</dd></dl>
	<p>For an implementation of quantile using sketches, check out the <a class="el" href="sketch_8sql__in.html#a2f2ab2fe3244515f5f73d49690e73b39" title="cmsketch_centile is a scalar UDF to compute a centile value from a cmsketch. Takes the results of the...">cmsketch_centile()</a> aggregate in the <a class="el" href="group__grp__countmin.html">CountMin (Cormode-Muthukrishnan)</a> module.</p>
	<dl class="section user"><dt>Implementation Notes</dt><dd>There are two implementations of quantile available depending on the size of the table. <code>quantile</code> is best used for small tables (e.g. less than 5000 rows, with 1-2 columns in total). For larger tables, consider using <code>quantile_big</code> instead.</dd></dl>
	<dl class="section user"><dt>Usage</dt><dd><pre>SELECT * FROM quantile( '<em>table_name</em>', '<em>col_name</em>', <em>quantile</em>);</pre> <pre>SELECT * FROM quantile_big( '<em>table_name</em>', '<em>col_name</em>', <em>quantile</em>);</pre></dd></dl>
	<dl class="section user"><dt>Examples</dt><dd><ol type="1">
	<li>Prepare some input: <pre class="fragment">sql> CREATE TABLE tab1 AS SELECT generate_series( 1,1000) as col1;
	</pre></li>
	<li>Run the <a class="el" href="quantile_8sql__in.html#a6955e44659a0817803ab7a11a9a7e8a5" title="Computes quantile. ">quantile()</a> function:<br/>
	<pre class="fragment">sql> SELECT quantile( 'tab1', 'col1', .3);

	quantile
	--------------
	301.48046875
	(1 row)
	</pre></li>
	</ol>
	</dd></dl>
	<dl class="section see"><dt>See Also</dt><dd>File <a class="el" href="quantile_8sql__in.html" title="SQL function for Quantile. ">quantile.sql_in</a> documenting the SQL function.<br/>
	<br/>
	Module <a class="el" href="group__grp__countmin.html">CountMin (Cormode-Muthukrishnan)</a> for an approximate <a class="el" href="quantile_8sql__in.html#a6955e44659a0817803ab7a11a9a7e8a5" title="Computes quantile. ">quantile</a> implementation. </dd></dl>
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