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postgresql/doc/src/sgml/ref/show.sgml

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Complete merge of all old man page information. ecpg reference page still needs formatting.
1999-07-22 17:09:15 +02:00
<!--
Fix cross-references, update examples, copy-edit.
2000-04-08 04:39:02 +02:00
$Header: /cvsroot/pgsql/doc/src/sgml/ref/show.sgml,v 1.9 2000/04/08 02:39:02 tgl Exp $
Complete merge of all old man page information. ecpg reference page still needs formatting.
1999-07-22 17:09:15 +02:00
Postgres documentation
-->
Minor updates for release. Split reference pages for CREATE TABLE AS and SELECT INTO to allow psgml (the emacs parser) to handle parsing.
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<refentry id="SQL-SHOW">
<refmeta>
Complete merge of all old man page information. ecpg reference page still needs formatting.
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<refentrytitle id="SQL-SHOW-TITLE">
Minor updates for release. Split reference pages for CREATE TABLE AS and SELECT INTO to allow psgml (the emacs parser) to handle parsing.
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SHOW
</refentrytitle>
<refmiscinfo>SQL - Language Statements</refmiscinfo>
</refmeta>
<refnamediv>
<refname>
SHOW
</refname>
<refpurpose>
Shows run-time parameters for session
</refpurpose>
</refnamediv>
<refsynopsisdiv>
<refsynopsisdivinfo>
Complete merge of all old man page information. ecpg reference page still needs formatting.
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<date>1999-07-20</date>
Minor updates for release. Split reference pages for CREATE TABLE AS and SELECT INTO to allow psgml (the emacs parser) to handle parsing.
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</refsynopsisdivinfo>
<synopsis>
Complete first pass at markup adjustments for docbook2man man pages. Add some internal cross references to select.sgml.
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SHOW <replaceable class="PARAMETER">keyword</replaceable>
Minor updates for release. Split reference pages for CREATE TABLE AS and SELECT INTO to allow psgml (the emacs parser) to handle parsing.
1999-06-14 09:37:05 +02:00
</synopsis>
Add new files from Oliver and Thomas.
1998-09-01 17:53:09 +02:00
Minor updates for release. Split reference pages for CREATE TABLE AS and SELECT INTO to allow psgml (the emacs parser) to handle parsing.
1999-06-14 09:37:05 +02:00
<refsect2 id="R2-SQL-SHOW-1">
<refsect2info>
<date>1998-09-24</date>
</refsect2info>
<title>
Inputs
</title>
Clean up to ensure tag completion as required by the newest versions of Norm's Modular Style Sheets and jade/docbook. From Vince Vielhaber <vev@michvhf.com>.
1998-12-29 03:24:47 +01:00
Complete first pass at markup adjustments for docbook2man man pages. Add some internal cross references to select.sgml.
1999-07-14 22:32:59 +02:00
<para>
Minor updates for release. Split reference pages for CREATE TABLE AS and SELECT INTO to allow psgml (the emacs parser) to handle parsing.
1999-06-14 09:37:05 +02:00
<variablelist>
<varlistentry>
Complete first pass at markup adjustments for docbook2man man pages. Add some internal cross references to select.sgml.
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<term><replaceable class="PARAMETER">keyword</replaceable></term>
Minor updates for release. Split reference pages for CREATE TABLE AS and SELECT INTO to allow psgml (the emacs parser) to handle parsing.
1999-06-14 09:37:05 +02:00
<listitem>
<para>
Fix cross-references, update examples, copy-edit.
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Refer to
<xref linkend="sql-set-title" endterm="sql-set-title">
for more information on available variables.
Minor updates for release. Split reference pages for CREATE TABLE AS and SELECT INTO to allow psgml (the emacs parser) to handle parsing.
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</para>
</listitem>
</varlistentry>
</variablelist>
</para>
</refsect2>
Clean up to ensure tag completion as required by the newest versions of Norm's Modular Style Sheets and jade/docbook. From Vince Vielhaber <vev@michvhf.com>.
1998-12-29 03:24:47 +01:00
Minor updates for release. Split reference pages for CREATE TABLE AS and SELECT INTO to allow psgml (the emacs parser) to handle parsing.
1999-06-14 09:37:05 +02:00
<refsect2 id="R2-SQL-SHOW-2">
<refsect2info>
<date>1998-09-24</date>
</refsect2info>
<title>
Outputs
</title>
Clean up to ensure tag completion as required by the newest versions of Norm's Modular Style Sheets and jade/docbook. From Vince Vielhaber <vev@michvhf.com>.
1998-12-29 03:24:47 +01:00
Complete first pass at markup adjustments for docbook2man man pages. Add some internal cross references to select.sgml.
1999-07-14 22:32:59 +02:00
<para>
Minor updates for release. Split reference pages for CREATE TABLE AS and SELECT INTO to allow psgml (the emacs parser) to handle parsing.
1999-06-14 09:37:05 +02:00
<variablelist>
<varlistentry>
Complete first pass at markup adjustments for docbook2man man pages. Add some internal cross references to select.sgml.
1999-07-14 22:32:59 +02:00
<term><computeroutput>
NOTICE: <replaceable class="PARAMETER">variable</replaceable> is <replaceable>value</replaceable>
</computeroutput></term>
Minor updates for release. Split reference pages for CREATE TABLE AS and SELECT INTO to allow psgml (the emacs parser) to handle parsing.
1999-06-14 09:37:05 +02:00
<listitem>
<para>
Complete first pass at markup adjustments for docbook2man man pages. Add some internal cross references to select.sgml.
1999-07-14 22:32:59 +02:00
Message returned if successful.
Minor updates for release. Split reference pages for CREATE TABLE AS and SELECT INTO to allow psgml (the emacs parser) to handle parsing.
1999-06-14 09:37:05 +02:00
</para>
</listitem>
</varlistentry>
<varlistentry>
Complete first pass at markup adjustments for docbook2man man pages. Add some internal cross references to select.sgml.
1999-07-14 22:32:59 +02:00
<term><computeroutput>
NOTICE: Unrecognized variable <replaceable>value</replaceable>
</computeroutput></term>
Minor updates for release. Split reference pages for CREATE TABLE AS and SELECT INTO to allow psgml (the emacs parser) to handle parsing.
1999-06-14 09:37:05 +02:00
<listitem>
<para>
Fix cross-references, update examples, copy-edit.
2000-04-08 04:39:02 +02:00
Message returned if <returnvalue>variable</returnvalue> does not exist.
Minor updates for release. Split reference pages for CREATE TABLE AS and SELECT INTO to allow psgml (the emacs parser) to handle parsing.
1999-06-14 09:37:05 +02:00
</para>
</listitem>
</varlistentry>
Complete first pass at markup adjustments for docbook2man man pages. Add some internal cross references to select.sgml.
1999-07-14 22:32:59 +02:00
Minor updates for release. Split reference pages for CREATE TABLE AS and SELECT INTO to allow psgml (the emacs parser) to handle parsing.
1999-06-14 09:37:05 +02:00
<varlistentry>
Complete first pass at markup adjustments for docbook2man man pages. Add some internal cross references to select.sgml.
1999-07-14 22:32:59 +02:00
<term><computeroutput>
NOTICE: Time zone is unknown
</computeroutput></term>
Minor updates for release. Split reference pages for CREATE TABLE AS and SELECT INTO to allow psgml (the emacs parser) to handle parsing.
1999-06-14 09:37:05 +02:00
<listitem>
<para>
Complete first pass at markup adjustments for docbook2man man pages. Add some internal cross references to select.sgml.
1999-07-14 22:32:59 +02:00
If the <envar>TZ</envar> or <envar>PGTZ</envar> environment
variable is not set.
Minor updates for release. Split reference pages for CREATE TABLE AS and SELECT INTO to allow psgml (the emacs parser) to handle parsing.
1999-06-14 09:37:05 +02:00
</para>
</listitem>
</varlistentry>
</variablelist>
</para>
</refsect2>
</refsynopsisdiv>
Clean up to ensure tag completion as required by the newest versions of Norm's Modular Style Sheets and jade/docbook. From Vince Vielhaber <vev@michvhf.com>.
1998-12-29 03:24:47 +01:00
Minor updates for release. Split reference pages for CREATE TABLE AS and SELECT INTO to allow psgml (the emacs parser) to handle parsing.
1999-06-14 09:37:05 +02:00
<refsect1 id="R1-SQL-SHOW-1">
<refsect1info>
<date>1998-09-24</date>
</refsect1info>
<title>
Description
</title>
<para>
New cost model for planning, incorporating a penalty for random page accesses versus sequential accesses, a (very crude) estimate of the effects of caching on random page accesses, and cost to evaluate WHERE- clause expressions. Export critical parameters for this model as SET variables. Also, create SET variables for the planner's enable flags (enable_seqscan, enable_indexscan, etc) so that these can be controlled more conveniently than via PGOPTIONS. Planner now estimates both startup cost (cost before retrieving first tuple) and total cost of each path, so it can optimize queries with LIMIT on a reasonable basis by interpolating between these costs. Same facility is a win for EXISTS(...) subqueries and some other cases. Redesign pathkey representation to achieve a major speedup in planning (I saw as much as 5X on a 10-way join); also minor changes in planner to reduce memory consumption by recycling discarded Path nodes and not constructing unnecessary lists. Minor cleanups to display more-plausible costs in some cases in EXPLAIN output. Initdb forced by change in interface to index cost estimation functions.
2000-02-15 21:49:31 +01:00
<command>SHOW</command> will display the current setting of a
run-time parameter during a session.
Minor updates for release. Split reference pages for CREATE TABLE AS and SELECT INTO to allow psgml (the emacs parser) to handle parsing.
1999-06-14 09:37:05 +02:00
</para>
<para>
New cost model for planning, incorporating a penalty for random page accesses versus sequential accesses, a (very crude) estimate of the effects of caching on random page accesses, and cost to evaluate WHERE- clause expressions. Export critical parameters for this model as SET variables. Also, create SET variables for the planner's enable flags (enable_seqscan, enable_indexscan, etc) so that these can be controlled more conveniently than via PGOPTIONS. Planner now estimates both startup cost (cost before retrieving first tuple) and total cost of each path, so it can optimize queries with LIMIT on a reasonable basis by interpolating between these costs. Same facility is a win for EXISTS(...) subqueries and some other cases. Redesign pathkey representation to achieve a major speedup in planning (I saw as much as 5X on a 10-way join); also minor changes in planner to reduce memory consumption by recycling discarded Path nodes and not constructing unnecessary lists. Minor cleanups to display more-plausible costs in some cases in EXPLAIN output. Initdb forced by change in interface to index cost estimation functions.
2000-02-15 21:49:31 +01:00
These variables can be set using the <command>SET</command> statement,
and
can be restored to the default values using the <command>RESET</command>
statement.
Minor updates for release. Split reference pages for CREATE TABLE AS and SELECT INTO to allow psgml (the emacs parser) to handle parsing.
1999-06-14 09:37:05 +02:00
Parameters and values are case-insensitive.
</para>
Clean up to ensure tag completion as required by the newest versions of Norm's Modular Style Sheets and jade/docbook. From Vince Vielhaber <vev@michvhf.com>.
1998-12-29 03:24:47 +01:00
Minor updates for release. Split reference pages for CREATE TABLE AS and SELECT INTO to allow psgml (the emacs parser) to handle parsing.
1999-06-14 09:37:05 +02:00
<refsect2 id="R2-SQL-SHOW-3">
<refsect2info>
<date>1998-09-24</date>
</refsect2info>
<title>
Notes
</title>
<para>
Fix cross-references, update examples, copy-edit.
2000-04-08 04:39:02 +02:00
See also
<xref linkend="sql-set-title" endterm="sql-set-title"> and
<xref linkend="sql-reset-title" endterm="sql-reset-title">
to manipulate variable values.
Minor updates for release. Split reference pages for CREATE TABLE AS and SELECT INTO to allow psgml (the emacs parser) to handle parsing.
1999-06-14 09:37:05 +02:00
</para>
</refsect2>
</refsect1>
<refsect1 id="R1-SQL-SHOW-2">
<title>
Usage
</title>
<para>
Complete first pass at markup adjustments for docbook2man man pages. Add some internal cross references to select.sgml.
1999-07-14 22:32:59 +02:00
Show the current <literal>DateStyle</literal> setting:
Minor updates for release. Split reference pages for CREATE TABLE AS and SELECT INTO to allow psgml (the emacs parser) to handle parsing.
1999-06-14 09:37:05 +02:00
<programlisting>
SHOW DateStyle;
Fix cross-references, update examples, copy-edit.
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NOTICE: DateStyle is ISO with US (NonEuropean) conventions
Complete first pass at markup adjustments for docbook2man man pages. Add some internal cross references to select.sgml.
1999-07-14 22:32:59 +02:00
</programlisting>
</para>
Minor updates for release. Split reference pages for CREATE TABLE AS and SELECT INTO to allow psgml (the emacs parser) to handle parsing.
1999-06-14 09:37:05 +02:00
Complete first pass at markup adjustments for docbook2man man pages. Add some internal cross references to select.sgml.
1999-07-14 22:32:59 +02:00
<para>
Show the current genetic optimizer (<literal>geqo</literal>) setting:
<programlisting>
Minor updates for release. Split reference pages for CREATE TABLE AS and SELECT INTO to allow psgml (the emacs parser) to handle parsing.
1999-06-14 09:37:05 +02:00
SHOW GEQO;
Fix cross-references, update examples, copy-edit.
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NOTICE: GEQO is ON beginning with 11 relations
Minor updates for release. Split reference pages for CREATE TABLE AS and SELECT INTO to allow psgml (the emacs parser) to handle parsing.
1999-06-14 09:37:05 +02:00
</programlisting>
</para>
</refsect1>
<refsect1 id="R1-SQL-SHOW-3">
<title>
Compatibility
</title>
<refsect2 id="R2-SQL-SHOW-4">
<refsect2info>
<date>1998-09-24</date>
</refsect2info>
<title>
SQL92
</title>
<para>
There is no <command>SHOW</command> defined in <acronym>SQL92</acronym>.
</para>
</refsect2>
</refsect1>
</refentry>
<!-- Keep this comment at the end of the file
Local variables:
mode: sgml
sgml-omittag:nil
sgml-shorttag:t
sgml-minimize-attributes:nil
sgml-always-quote-attributes:t
sgml-indent-step:1
sgml-indent-data:t
sgml-parent-document:nil
sgml-default-dtd-file:"../reference.ced"
sgml-exposed-tags:nil
Complete first pass at markup adjustments for docbook2man man pages. Add some internal cross references to select.sgml.
1999-07-14 22:32:59 +02:00
sgml-local-catalogs:"/usr/lib/sgml/catalog"
Minor updates for release. Split reference pages for CREATE TABLE AS and SELECT INTO to allow psgml (the emacs parser) to handle parsing.
1999-06-14 09:37:05 +02:00
sgml-local-ecat-files:nil
End:
-->