Sophie: postgresql8.3-docs-8.3.6-2mdv2008.1 x86

postgresql8.3-docs-8.3.6-2mdv2008.1.x86_64.rpm

<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
<HTML
><HEAD
><TITLE
>Setting Parameters</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 8.3.6 Documentation"
HREF="index.html"><LINK
REL="UP"
TITLE="Server Configuration"
HREF="runtime-config.html"><LINK
REL="PREVIOUS"
TITLE="Server Configuration"
HREF="runtime-config.html"><LINK
REL="NEXT"
TITLE="File Locations"
HREF="runtime-config-file-locations.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="2009-02-03T04:34:16"></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 8.3.6 Documentation</TH
></TR
><TR
><TD
WIDTH="10%"
ALIGN="left"
VALIGN="top"
><A
HREF="runtime-config.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 18. 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-file-locations.html"
ACCESSKEY="N"
>Next</A
></TD
></TR
></TABLE
><HR
ALIGN="LEFT"
WIDTH="100%"></DIV
><DIV
CLASS="SECT1"
><H1
CLASS="SECT1"
><A
NAME="CONFIG-SETTING"
>18.1. Setting Parameters</A
></H1
><P
>    All parameter names are case-insensitive. Every parameter takes a
    value of one of four types: Boolean, integer, floating point,
    or string. Boolean values can be written as <TT
CLASS="LITERAL"
>ON</TT
>,
    <TT
CLASS="LITERAL"
>OFF</TT
>, <TT
CLASS="LITERAL"
>TRUE</TT
>,
    <TT
CLASS="LITERAL"
>FALSE</TT
>, <TT
CLASS="LITERAL"
>YES</TT
>,
    <TT
CLASS="LITERAL"
>NO</TT
>, <TT
CLASS="LITERAL"
>1</TT
>, <TT
CLASS="LITERAL"
>0</TT
>
    (all case-insensitive) or any unambiguous prefix of these.
   </P
><P
>    Some settings specify a memory or time value.  Each of these has an
    implicit unit, which is either kilobytes, blocks (typically eight
    kilobytes), milliseconds, seconds, or minutes.  Default units can be
    queried by referencing <TT
CLASS="LITERAL"
>pg_settings.unit</TT
>. For convenience,
    a different unit can also be specified explicitly.  Valid memory units
    are <TT
CLASS="LITERAL"
>kB</TT
> (kilobytes), <TT
CLASS="LITERAL"
>MB</TT
>
    (megabytes), and <TT
CLASS="LITERAL"
>GB</TT
> (gigabytes); valid time units
    are <TT
CLASS="LITERAL"
>ms</TT
> (milliseconds), <TT
CLASS="LITERAL"
>s</TT
>
    (seconds), <TT
CLASS="LITERAL"
>min</TT
> (minutes), <TT
CLASS="LITERAL"
>h</TT
>
    (hours), and <TT
CLASS="LITERAL"
>d</TT
> (days).  Note that the multiplier
    for memory units is 1024, not 1000.
   </P
><P
>    One way to set these parameters is to edit the file
    <TT
CLASS="FILENAME"
>postgresql.conf</TT
><A
NAME="AEN22528"
></A
>,
    which is normally kept in the data directory. (<SPAN
CLASS="APPLICATION"
>initdb</SPAN
>
    installs a default copy there.) An example of what this file might look
    like is:
</P><PRE
CLASS="PROGRAMLISTING"
># This is a comment
log_connections = yes
log_destination = 'syslog'
search_path = '"$user", public'
shared_buffers = 128MB</PRE
><P>
    One parameter is specified per line. The equal sign between name and
    value is optional. Whitespace is insignificant and blank lines are
    ignored. Hash marks (<TT
CLASS="LITERAL"
>#</TT
>) introduce comments
    anywhere.  Parameter values that are not simple identifiers or
    numbers must be single-quoted.  To embed a single quote in a parameter
    value, write either two quotes (preferred) or backslash-quote.
   </P
><P
>    <A
NAME="AEN22534"
></A
>
    In addition to parameter settings, the <TT
CLASS="FILENAME"
>postgresql.conf</TT
>
    file can contain <I
CLASS="FIRSTTERM"
>include directives</I
>, which specify
    another file to read and process as if it were inserted into the
    configuration file at this point.  Include directives simply look like:
</P><PRE
CLASS="PROGRAMLISTING"
>include 'filename'</PRE
><P>
    If the file name is not an absolute path, it is taken as relative to
    the directory containing the referencing configuration file.
    Inclusions can be nested.
   </P
><P
>    <A
NAME="AEN22542"
></A
>
    The configuration file is reread whenever the main server process receives a
    <SPAN
CLASS="SYSTEMITEM"
>SIGHUP</SPAN
> signal (which is most easily sent by means
    of <TT
CLASS="LITERAL"
>pg_ctl reload</TT
>). The main server process
    also propagates this signal to all currently running server
    processes so that existing sessions also get the new
    value. Alternatively, you can send the signal to a single server
    process directly.  Some parameters can only be set at server start;
    any changes to their entries in the configuration file will be ignored
    until the server is restarted.
   </P
><P
>    A second way to set these configuration parameters is to give them
    as a command-line option to the <TT
CLASS="COMMAND"
>postgres</TT
> command, such as:
</P><PRE
CLASS="PROGRAMLISTING"
>postgres -c log_connections=yes -c log_destination='syslog'</PRE
><P>
    Command-line options override any conflicting settings in
    <TT
CLASS="FILENAME"
>postgresql.conf</TT
>.  Note that this means you won't
    be able to change the value on-the-fly by editing
    <TT
CLASS="FILENAME"
>postgresql.conf</TT
>, so while the command-line
    method might be convenient, it can cost you flexibility later.
   </P
><P
>    Occasionally it is useful to give a command line option to
    one particular session only. The environment variable
    <TT
CLASS="ENVAR"
>PGOPTIONS</TT
> can be used for this purpose on the
    client side:
</P><PRE
CLASS="PROGRAMLISTING"
>env PGOPTIONS='-c geqo=off' psql</PRE
><P>
    (This works for any <SPAN
CLASS="APPLICATION"
>libpq</SPAN
>-based client application, not
    just <SPAN
CLASS="APPLICATION"
>psql</SPAN
>.) Note that this won't work for
    parameters that are fixed when the server is started or that must be
    specified in <TT
CLASS="FILENAME"
>postgresql.conf</TT
>.
   </P
><P
>    Furthermore, it is possible to assign a set of parameter settings to
    a user or a database.  Whenever a session is started, the default
    settings for the user and database involved are loaded.  The
    commands <A
HREF="sql-alteruser.html"
><I
>ALTER USER</I
></A
>
    and <A
HREF="sql-alterdatabase.html"
><I
>ALTER DATABASE</I
></A
>,
    respectively, are used to configure these settings.  Per-database
    settings override anything received from the
    <TT
CLASS="COMMAND"
>postgres</TT
> command-line or the configuration
    file, and in turn are overridden by per-user settings; both are
    overridden by per-session settings.
   </P
><P
>    Some parameters can be changed in individual <ACRONYM
CLASS="ACRONYM"
>SQL</ACRONYM
>
    sessions with the <A
HREF="sql-set.html"
><I
>SET</I
></A
>
    command, for example:
</P><PRE
CLASS="SCREEN"
>SET ENABLE_SEQSCAN TO OFF;</PRE
><P>
    If <TT
CLASS="COMMAND"
>SET</TT
> is allowed, it overrides all other sources of
    values for the parameter. Some parameters cannot be changed via
    <TT
CLASS="COMMAND"
>SET</TT
>: for example, if they control behavior that
    cannot be changed without restarting the entire
    <SPAN
CLASS="PRODUCTNAME"
>PostgreSQL</SPAN
> server.  Also, some parameters can
    be modified via <TT
CLASS="COMMAND"
>SET</TT
> or <TT
CLASS="COMMAND"
>ALTER</TT
> by superusers,
    but not by ordinary users.
   </P
><P
>    The <A
HREF="sql-show.html"
><I
>SHOW</I
></A
>
    command allows inspection of the current values of all parameters.
   </P
><P
>    The virtual table <TT
CLASS="STRUCTNAME"
>pg_settings</TT
>
    (described in <A
HREF="view-pg-settings.html"
>Section 44.51</A
>) also allows
    displaying and updating session run-time parameters.  It is equivalent
    to <TT
CLASS="COMMAND"
>SHOW</TT
> and <TT
CLASS="COMMAND"
>SET</TT
>, but can be more convenient
    to use because it can be joined with other tables, or selected from using
    any desired selection condition.
   </P
></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.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-file-locations.html"
ACCESSKEY="N"
>Next</A
></TD
></TR
><TR
><TD
WIDTH="33%"
ALIGN="left"
VALIGN="top"
>Server Configuration</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"
>File Locations</TD
></TR
></TABLE
></DIV
></BODY
></HTML
>