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Make pg_stat_file() use OUT parameters so that the user doesn't have to

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remember the output parameter set for himself.  It's a bit of a kluge
but fixing array_in to work in bootstrap mode looks worse.
I removed the separate pg_file_length() function, as it no longer has any
real notational advantage --- you can write (pg_stat_file(...)).length.
This commit is contained in:
Tom Lane
2005-08-13 19:02:34 +00:00
parent f547909db7
commit 2af9a44fa9
5 changed files with 80 additions and 73 deletions
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111
doc/src/sgml/func.sgml
View File

@ -1,5 +1,5 @@
<!--
$PostgreSQL: pgsql/doc/src/sgml/func.sgml,v 1.279 2005/08/12 18:23:53 tgl Exp $
$PostgreSQL: pgsql/doc/src/sgml/func.sgml,v 1.280 2005/08/13 19:02:32 tgl Exp $
PostgreSQL documentation
-->
@ -9064,6 +9064,9 @@ SELECT set_config('log_statement_stats', 'off', false);
<indexterm zone="functions-admin">
<primary>pg_reload_conf</primary>
</indexterm>
<indexterm zone="functions-admin">
<primary>pg_rotate_logfile</primary>
</indexterm>
<indexterm zone="functions-admin">
<primary>signal</primary>
@ -9100,23 +9103,44 @@ SELECT set_config('log_statement_stats', 'off', false);
<entry><type>int</type></entry>
<entry>Cause server processes to reload their configuration files</entry>
</row>
<row>
<entry>
<literal><function>pg_rotate_logfile</function>()</literal>
</entry>
<entry><type>int</type></entry>
<entry>Rotate server's logfile</entry>
</row>
</tbody>
</tgroup>
</table>
<para>
These functions return 1 if successful, 0 if not successful.
The process ID (<literal>pid</literal>) of an active backend can be found
from the <structfield>procpid</structfield> column in the
<structname>pg_stat_activity</structname> view, or by listing the <command>postgres</command>
processes on the server with <application>ps</>.
Each of these functions returns 1 if successful, 0 if not successful.
</para>
<para>
<function>pg_cancel_backend</> sends a Query Cancel (SIGINT) signal
to a backend process identified by process ID (<literal>pid</literal>).
The process ID of an active backend can be found from the
<structfield>procpid</structfield> column in the
<structname>pg_stat_activity</structname> view, or by listing the
<command>postgres</command> processes on the server with
<application>ps</>.
</para>
<para>
<function>pg_reload_conf</> sends a SIGHUP signal to the
postmaster, causing reload of the configuration files
in all server processes.
</para>
<para>
<function>pg_rotate_logfile</> signals the logfile manager to switch
to a new output file immediately. This works only when
<varname>redirect_stderr</> is used for logging, since otherwise there
is no logfile manager subprocess.
</para>
<indexterm zone="functions-admin">
<primary>pg_start_backup</primary>
</indexterm>
@ -9341,22 +9365,9 @@ SELECT set_config('log_statement_stats', 'off', false);
</thead>
<tbody>
<row>
<entry>
<literal><function>pg_file_length</function>(<parameter>filename</> <type>text</>)</literal>
<indexterm zone="functions-admin">
<primary>pg_file_length</primary>
</indexterm>
</entry>
<entry><type>int8</type></entry>
<entry>Return the file length</entry>
</row>
<row>
<entry>
<literal><function>pg_ls_dir</function>(<parameter>dirname</> <type>text</>)</literal>
<indexterm zone="functions-admin">
<primary>pg_ls_dir</primary>
</indexterm>
</entry>
<entry><type>setof text</type></entry>
<entry>List the contents of a directory</entry>
@ -9373,69 +9384,45 @@ SELECT set_config('log_statement_stats', 'off', false);
<literal><function>pg_stat_file</function>(<parameter>filename</> <type>text</>)</literal>
</entry>
<entry><type>record</type></entry>
<entry>Return information about the file</entry>
<entry>Return information about a file</entry>
</row>
</tbody>
</tgroup>
</table>
<indexterm zone="functions-admin">
<primary>pg_ls_dir</primary>
</indexterm>
<para>
<function>pg_ls_dir()</> returns all the names in the specified
directory, except the special entries <quote><literal>.</></> and
<quote><literal>..</></>.
</para>
<indexterm zone="functions-admin">
<primary>pg_read_file</primary>
</indexterm>
<para>
<function>pg_read_file()</> returns part of a textfile, starting
at the given offset, returning at most length bytes (less if the
end of file is reached first). If offset is negative,
it is relative to the end of the file.
<function>pg_read_file()</> returns part of a text file, starting
at the given <parameter>offset</>, returning at most <parameter>length</>
bytes (less if the end of file is reached first). If <parameter>offset</>
is negative, it is relative to the end of the file.
</para>
<indexterm zone="functions-admin">
<primary>pg_stat_file</primary>
</indexterm>
<para>
<function>pg_stat_file()</> returns a record containing the
<function>pg_stat_file()</> returns a record containing the file
length, last accessed timestamp, last modified timestamp,
creation timestamp, and a flag indicating if it is a directory.
Use it like this:
creation timestamp, and a boolean indicating if it is a directory.
Typical usages include:
<programlisting>
SELECT *
FROM pg_stat_file('filename')
AS s(length int8, atime timestamptz, mtime timestamptz,
ctime timestamptz, isdir bool);
SELECT * FROM pg_stat_file('filename');
SELECT (pg_stat_file('filename')).mtime;
</programlisting>
</para>
<para>
The function shown in <xref
linkend="functions-admin-logfile"> forces the server
logfile to be rotated. This works only when <varname>redirect_stderr</>
is used for logging. Use of this function is restricted
to superusers.
</para>
<table id="functions-admin-logfile">
<title>Server Logfile Functions</title>
<tgroup cols="3">
<thead>
<row><entry>Name</entry> <entry>Return Type</entry> <entry>Description</entry>
</row>
</thead>
<tbody>
<row>
<entry>
<literal><function>pg_rotate_logfile</function>()</literal>
<indexterm zone="functions-admin">
<primary>pg_rotate_logfile</primary>
</indexterm>
</entry>
<entry><type>int</type></entry>
<entry>Rotate server's logfile</entry>
</row>
</tbody>
</tgroup>
</table>
</sect1>
</chapter>