docs - update GUC optimizer_analyze_root_partition
* docs - update GUC optimizer_analyze_root_partition
change default to on
update description
* docs - optimizer_analyze_root_partition, fix typo
<body>
<note>The <codeph>memory_spill_ratio</codeph> server configuration parameter is enforced only
when resource group-based resource management is active.</note>
- <p>Sets the memory usage threshold percentage for memory-intensive operators in a transaction. When
- a transaction reaches this threshold, it spills to disk.</p>
- <p>The default <codeph>memory_spill_ratio</codeph> percentage is the value defined for the resource group
- assigned to the currently active role. You can set <codeph>memory_spill_ratio</codeph> at
- the session level to selectively set this limit on a per-query basis. For example, if you
- have a specific query that spills to disk and requires more memory, you may choose to set a
- larger <codeph>memory_spill_ratio</codeph> to increase the initial memory allocation.</p>
+ <p>Sets the memory usage threshold percentage for memory-intensive operators in a transaction.
+ When a transaction reaches this threshold, it spills to disk.</p>
+ <p>The default <codeph>memory_spill_ratio</codeph> percentage is the value defined for the
+ resource group assigned to the currently active role. You can set
+ <codeph>memory_spill_ratio</codeph> at the session level to selectively set this limit on
+ a per-query basis. For example, if you have a specific query that spills to disk and
+ requires more memory, you may choose to set a larger <codeph>memory_spill_ratio</codeph> to
+ increase the initial memory allocation.</p>
<p>When you set <codeph>memory_spill_ratio</codeph> at the session level, Greenplum Database
does not perform semantic validation on the new value until you next perform a query.</p>
<table id="memory_spill_ratio_table">
<p>For a partitioned table, collects statistics for the root partition when the
<cmdname>ANALYZE</cmdname> command is run on the table. GPORCA uses the root partition
statistics when generating a query plan. The legacy query optimizer does not use these
- statistics. If you set the value of the server configuration parameter <codeph><xref
- href="#optimizer" format="dita"/></codeph> to on, set the value of this parameter to on
- and run the command <cmdname>ANALYZE</cmdname> or <cmdname>ANALYZE ROOTPARTITION</cmdname>
- on partitioned tables to ensure the proper statistics have been collected. </p>
+ statistics. When the value of the server configuration parameter <codeph><xref
+ href="#optimizer" format="dita"/></codeph> is on (the default), the value of this
+ parameter should also be on (the default). For information about collecting table statistics
+ on partitioned tables, see <codeph><xref href="../sql_commands/ANALYZE.xml"/></codeph>.</p>
<p>For information about the legacy query optimizer and GPORCA, see <xref
href="../../admin_guide/query/topics/query.xml">Querying Data</xref><ph
otherprops="op-print"> in the <cite>Greenplum Database Administrator
<tbody>
<row>
<entry colname="col1">Boolean</entry>
- <entry colname="col2">off</entry>
+ <entry colname="col2">on</entry>
<entry colname="col3">master<p>session</p><p>reload</p></entry>
</row>
</tbody>
