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<REFENTRY ID="SQL-EXPLAIN">
<REFMETA>
<REFENTRYTITLE>
EXPLAIN
</REFENTRYTITLE>
<REFMISCINFO>SQL - Language Statements</REFMISCINFO>
</REFMETA>
<REFNAMEDIV>
<REFNAME>
EXPLAIN
</REFNAME>
<REFPURPOSE>
Shows statement execution details.
</REFPURPOSE>
<REFSYNOPSISDIV>
<REFSYNOPSISDIVINFO>
<DATE>1998-09-01</DATE>
</REFSYNOPSISDIVINFO>
<SYNOPSIS>
EXPLAIN [ VERBOSE ] <REPLACEABLE CLASS="PARAMETER">query</REPLACEABLE>
</SYNOPSIS>
<REFSECT2 ID="R2-SQL-EXPLAIN-1">
<REFSECT2INFO>
<DATE>1998-09-01</DATE>
</REFSECT2INFO>
<TITLE>
Inputs
</TITLE>
<PARA>
<VARIABLELIST>
<VARLISTENTRY>
<TERM>
VERBOSE
</TERM>
<LISTITEM>
<PARA>
Flag to show detailed query plan.
<VARLISTENTRY>
<TERM>
<REPLACEABLE CLASS="PARAMETER">query</REPLACEABLE>
</TERM>
<LISTITEM>
<PARA>
Any <REPLACEABLE CLASS="PARAMETER">query</REPLACEABLE>.
</VARIABLELIST>
</REFSECT2>
<REFSECT2 ID="R2-SQL-EXPLAIN-2">
<REFSECT2INFO>
<DATE>1998-04-15</DATE>
</REFSECT2INFO>
<TITLE>
Outputs
</TITLE>
<PARA>
<VARIABLELIST>
<VARLISTENTRY>
<TERM>
NOTICE: QUERY PLAN:
</TERM>
<LISTITEM>
<PARA>
Explicit query plan from the <productname>Postgres</productname> backend.
<VARLISTENTRY>
<TERM>
EXPLAIN
</TERM>
<LISTITEM>
<PARA>
Flag sent after query plan is shown.
</VARIABLELIST>
</REFSECT2>
</REFSYNOPSISDIV>
<REFSECT1 ID="R1-SQL-EXPLAIN-1">
<REFSECT1INFO>
<DATE>1998-04-15</DATE>
</REFSECT1INFO>
<TITLE>
Description
</TITLE>
<PARA>
This command outputs details about the supplied query.
The default output is the computed query cost.
VERBOSE displays the full query plan and cost.
<REFSECT2 ID="R2-SQL-EXPLAIN-3">
<REFSECT2INFO>
<DATE>1998-04-15</DATE>
</REFSECT2INFO>
<TITLE>
Notes
</TITLE>
<PARA>
</REFSECT2>
<REFSECT1 ID="R1-SQL-EXPLAIN-2">
<TITLE>
Usage
</TITLE>
<PARA>
To show a query plan for a simple query:
<ProgramListing>
postgres=> explain select * from foo;
NOTICE: QUERY PLAN:
Seq Scan on foo (cost=0.00 size=0 width=4)
EXPLAIN
</ProgramListing>
</REFSECT1>
<REFSECT1 ID="R1-SQL-EXPLAIN-3">
<TITLE>
Compatibility
</TITLE>
<PARA>
</PARA>
<REFSECT2 ID="R2-SQL-EXPLAIN-4">
<REFSECT2INFO>
<DATE>1998-09-01</DATE>
</REFSECT2INFO>
<TITLE>
SQL92
</TITLE>
<PARA>
There is no EXPLAIN statement defined in SQL92.
</REFENTRY>
<!--
<REPLACEABLE CLASS="PARAMETER">
</REPLACEABLE>
<ReturnValue></ReturnValue>
<PARA>
</PARA>
<VARIABLELIST>
<VARLISTENTRY>
<TERM>•
</TERM>
<LISTITEM>
<PARA>
</PARA>
</LISTITEM>
</VARLISTENTRY>
</VARIABLELIST>
<PARA>
</PARA>
-->
|
