|
Server : Apache/2.2.2 (Fedora) System : Linux App1.pathumtani.go.th 2.6.20-1.2320.fc5smp #1 SMP Tue Jun 12 19:40:16 EDT 2007 i686 User : apache ( 48) PHP Version : 5.2.9 Disable Function : NONE Directory : /proc/self/root/usr/share/doc/postgresql-8.1.9/html/ |
Upload File : |
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
<HTML
><HEAD
><TITLE
>Automatic Vacuuming</TITLE
><META
NAME="GENERATOR"
CONTENT="Modular DocBook HTML Stylesheet Version 1.79"><LINK
REV="MADE"
HREF="mailto:pgsql-docs@postgresql.org"><LINK
REL="HOME"
TITLE="PostgreSQL 8.1.9 Documentation"
HREF="index.html"><LINK
REL="UP"
TITLE="Server Configuration"
HREF="runtime-config.html"><LINK
REL="PREVIOUS"
TITLE="Run-Time Statistics"
HREF="runtime-config-statistics.html"><LINK
REL="NEXT"
TITLE="Client Connection Defaults"
HREF="runtime-config-client.html"><LINK
REL="STYLESHEET"
TYPE="text/css"
HREF="stylesheet.css"><META
HTTP-EQUIV="Content-Type"
CONTENT="text/html; charset=ISO-8859-1"><META
NAME="creation"
CONTENT="2007-04-20T04:40:08"></HEAD
><BODY
CLASS="SECT1"
><DIV
CLASS="NAVHEADER"
><TABLE
SUMMARY="Header navigation table"
WIDTH="100%"
BORDER="0"
CELLPADDING="0"
CELLSPACING="0"
><TR
><TH
COLSPAN="5"
ALIGN="center"
VALIGN="bottom"
>PostgreSQL 8.1.9 Documentation</TH
></TR
><TR
><TD
WIDTH="10%"
ALIGN="left"
VALIGN="top"
><A
HREF="runtime-config-statistics.html"
ACCESSKEY="P"
>Prev</A
></TD
><TD
WIDTH="10%"
ALIGN="left"
VALIGN="top"
><A
HREF="runtime-config.html"
>Fast Backward</A
></TD
><TD
WIDTH="60%"
ALIGN="center"
VALIGN="bottom"
>Chapter 17. Server Configuration</TD
><TD
WIDTH="10%"
ALIGN="right"
VALIGN="top"
><A
HREF="runtime-config.html"
>Fast Forward</A
></TD
><TD
WIDTH="10%"
ALIGN="right"
VALIGN="top"
><A
HREF="runtime-config-client.html"
ACCESSKEY="N"
>Next</A
></TD
></TR
></TABLE
><HR
ALIGN="LEFT"
WIDTH="100%"></DIV
><DIV
CLASS="SECT1"
><H1
CLASS="SECT1"
><A
NAME="RUNTIME-CONFIG-AUTOVACUUM"
>17.9. Automatic Vacuuming</A
></H1
><A
NAME="AEN20092"
></A
><P
> These settings control the default behavior for the <I
CLASS="FIRSTTERM"
>autovacuum
daemon</I
>. Please refer to <A
HREF="maintenance.html#AUTOVACUUM"
>Section 22.1.4</A
> for
more information.
</P
><P
></P
><DIV
CLASS="VARIABLELIST"
><DL
><DT
><A
NAME="GUC-AUTOVACUUM"
></A
><TT
CLASS="VARNAME"
>autovacuum</TT
> (<TT
CLASS="TYPE"
>boolean</TT
>)</DT
><DD
><P
> Controls whether the server should start the
autovacuum subprocess. This is off by default.
<TT
CLASS="VARNAME"
>stats_start_collector</TT
> and <TT
CLASS="VARNAME"
>stats_row_level</TT
>
must also be on for this to start.
This option can be set at server start or in the
<TT
CLASS="FILENAME"
>postgresql.conf</TT
> file.
</P
></DD
><DT
><A
NAME="GUC-AUTOVACUUM-NAPTIME"
></A
><TT
CLASS="VARNAME"
>autovacuum_naptime</TT
> (<TT
CLASS="TYPE"
>integer</TT
>)</DT
><DD
><P
> Specifies the delay between activity rounds for the autovacuum
subprocess. In each round the subprocess examines one database
and issues <TT
CLASS="COMMAND"
>VACUUM</TT
> and <TT
CLASS="COMMAND"
>ANALYZE</TT
> commands
as needed for tables in that database. The delay is measured
in seconds, and the default is 60.
This option can be set at server start or in the
<TT
CLASS="FILENAME"
>postgresql.conf</TT
> file.
</P
></DD
><DT
><A
NAME="GUC-AUTOVACUUM-VACUUM-THRESHOLD"
></A
><TT
CLASS="VARNAME"
>autovacuum_vacuum_threshold</TT
> (<TT
CLASS="TYPE"
>integer</TT
>)</DT
><DD
><P
> Specifies the minimum number of updated or deleted tuples needed
to trigger a <TT
CLASS="COMMAND"
>VACUUM</TT
> in any one table.
The default is 1000.
This option can be set at server start or in the
<TT
CLASS="FILENAME"
>postgresql.conf</TT
> file.
This setting can be overridden for individual tables by entries in
<TT
CLASS="STRUCTNAME"
>pg_autovacuum</TT
>.
</P
></DD
><DT
><A
NAME="GUC-AUTOVACUUM-ANALYZE-THRESHOLD"
></A
><TT
CLASS="VARNAME"
>autovacuum_analyze_threshold</TT
> (<TT
CLASS="TYPE"
>integer</TT
>)</DT
><DD
><P
> Specifies the minimum number of inserted, updated or deleted tuples
needed to trigger an <TT
CLASS="COMMAND"
>ANALYZE</TT
> in any one table.
The default is 500.
This option can be set at server start or in the
<TT
CLASS="FILENAME"
>postgresql.conf</TT
> file.
This setting can be overridden for individual tables by entries in
<TT
CLASS="STRUCTNAME"
>pg_autovacuum</TT
>.
</P
></DD
><DT
><A
NAME="GUC-AUTOVACUUM-VACUUM-SCALE-FACTOR"
></A
><TT
CLASS="VARNAME"
>autovacuum_vacuum_scale_factor</TT
> (<TT
CLASS="TYPE"
>floating point</TT
>)</DT
><DD
><P
> Specifies a fraction of the table size to add to
<TT
CLASS="VARNAME"
>autovacuum_vacuum_threshold</TT
>
when deciding whether to trigger a <TT
CLASS="COMMAND"
>VACUUM</TT
>.
The default is 0.4.
This option can be set at server start or in the
<TT
CLASS="FILENAME"
>postgresql.conf</TT
> file.
This setting can be overridden for individual tables by entries in
<TT
CLASS="STRUCTNAME"
>pg_autovacuum</TT
>.
</P
></DD
><DT
><A
NAME="GUC-AUTOVACUUM-ANALYZE-SCALE-FACTOR"
></A
><TT
CLASS="VARNAME"
>autovacuum_analyze_scale_factor</TT
> (<TT
CLASS="TYPE"
>floating point</TT
>)</DT
><DD
><P
> Specifies a fraction of the table size to add to
<TT
CLASS="VARNAME"
>autovacuum_analyze_threshold</TT
>
when deciding whether to trigger an <TT
CLASS="COMMAND"
>ANALYZE</TT
>.
The default is 0.2.
This option can be set at server start or in the
<TT
CLASS="FILENAME"
>postgresql.conf</TT
> file.
This setting can be overridden for individual tables by entries in
<TT
CLASS="STRUCTNAME"
>pg_autovacuum</TT
>.
</P
></DD
><DT
><A
NAME="GUC-AUTOVACUUM-VACUUM-COST-DELAY"
></A
><TT
CLASS="VARNAME"
>autovacuum_vacuum_cost_delay</TT
> (<TT
CLASS="TYPE"
>integer</TT
>)</DT
><DD
><P
> Specifies the cost delay value that will be used in automatic
<TT
CLASS="COMMAND"
>VACUUM</TT
> operations. If -1 is specified (which is the
default), the regular
<A
HREF="runtime-config-resource.html#GUC-VACUUM-COST-DELAY"
>vacuum_cost_delay</A
> value will be used.
This setting can be overridden for individual tables by entries in
<TT
CLASS="STRUCTNAME"
>pg_autovacuum</TT
>.
</P
></DD
><DT
><A
NAME="GUC-AUTOVACUUM-VACUUM-COST-LIMIT"
></A
><TT
CLASS="VARNAME"
>autovacuum_vacuum_cost_limit</TT
> (<TT
CLASS="TYPE"
>integer</TT
>)</DT
><DD
><P
> Specifies the cost limit value that will be used in automatic
<TT
CLASS="COMMAND"
>VACUUM</TT
> operations. If -1 is specified (which is the
default), the regular
<A
HREF="runtime-config-resource.html#GUC-VACUUM-COST-LIMIT"
>vacuum_cost_limit</A
> value will be used.
This setting can be overridden for individual tables by entries in
<TT
CLASS="STRUCTNAME"
>pg_autovacuum</TT
>.
</P
></DD
></DL
></DIV
></DIV
><DIV
CLASS="NAVFOOTER"
><HR
ALIGN="LEFT"
WIDTH="100%"><TABLE
SUMMARY="Footer navigation table"
WIDTH="100%"
BORDER="0"
CELLPADDING="0"
CELLSPACING="0"
><TR
><TD
WIDTH="33%"
ALIGN="left"
VALIGN="top"
><A
HREF="runtime-config-statistics.html"
ACCESSKEY="P"
>Prev</A
></TD
><TD
WIDTH="34%"
ALIGN="center"
VALIGN="top"
><A
HREF="index.html"
ACCESSKEY="H"
>Home</A
></TD
><TD
WIDTH="33%"
ALIGN="right"
VALIGN="top"
><A
HREF="runtime-config-client.html"
ACCESSKEY="N"
>Next</A
></TD
></TR
><TR
><TD
WIDTH="33%"
ALIGN="left"
VALIGN="top"
>Run-Time Statistics</TD
><TD
WIDTH="34%"
ALIGN="center"
VALIGN="top"
><A
HREF="runtime-config.html"
ACCESSKEY="U"
>Up</A
></TD
><TD
WIDTH="33%"
ALIGN="right"
VALIGN="top"
>Client Connection Defaults</TD
></TR
></TABLE
></DIV
></BODY
></HTML
>