<cmdsynopsis>

<command>pg_xlogdump</command>

<arg rep="repeat" choice="opt"><option>option</option></arg>

<arg rep="repeat" choice="opt"><option>timestamp-option</option></arg>

<arg choice="opt"><option>startseg</option>

<arg choice="opt"><option>endseg</option></arg>

</arg>

<refsect1 id="R1-APP-PGXLOGDUMP-1">

<title>Description</title>

<para>

<command>pg_xlogdump</command> displays the write-ahead log (WAL) andis mainly

useful for debugging or educational purposes.

<command>pg_xlogdump</command> displays the write-ahead log (WAL) andprints timestamps for WAL records.

This utility is mainlyuseful for debugging or educational purposes.

</para>

<para>

<term><replaceable class="parameter">startseg</replaceable></term>

<listitem>

<para>

Start reading at the specified log segment file.This implicitly determines

Start reading at the specified log segment file. This implicitly determines

the path in which files will be searched for, and the timeline to use.

</para>

</listitem>

<term><option>--path=<replaceable>path</replaceable></option></term>

<listitem>

<para>

Specifies a directory to search for log segment files or a

Specify a directory to search for log segment files or a

directory with a <literal>pg_xlog</literal> subdirectory that

contains such files.The default is to search in the current

contains such files. The default is to search in the current

directory, the <literal>pg_xlog</literal> subdirectory of the

current directory, and the <literal>pg_xlog</literal> subdirectory

of <envar>PGDATA</envar>.

<term><option>--rmgr=<replaceable>rmgr</replaceable></option></term>

<listitem>

<para>

Only display records generated by the specified resource manager.

If <literal>list</>is passedasname, print a list of valid resource manager

names, andexit.

Only display records generated by the specified<literal>rmgr</literal>resource manager.

Ifyou pass<literal>list</> asan argument, <application>pg_xlogdump</application> prints a list of valid resource manager

names andexits.

</para>

</listitem>

</varlistentry>

</varlistentry>

</variablelist>

</para>

<para>

The following command-line options enable printing timestamps for various types of WAL records. You can use these options together with

<replaceable class="parameter">startseg</replaceable>, <replaceable class="parameter">endseg</replaceable>, <option>-s</option>, and <option>-e</option> options.

<variablelist>

<varlistentry>

<term><option>-E</option></term>

<listitem>

<para>

Print the timestamp of the last WAL record of the specified type found in the log segment file. When using this option, you must also specify the <option>-S</option> option.</para>

<para>By default, <application>pg_xlogdump</application> prints timestamps only for COMMIT records. You can specify other record types using the <option>-F</option> option.

</para>

</listitem>

</varlistentry>

<varlistentry>

<term><option>-F</option> [<replaceable>argument1</replaceable>,<replaceable>argument2</replaceable>,...]</term>

<listitem>

<para>

Specify WAL record types for which to print timestamps. When using this option, you must also specify the <option>-S</option> option.</para>

<para>The <option>-F</option> option can take the following arguments, in the comma-separated format:</para>

<itemizedlist>

<listitem>

<para><option>XLOG_RESTORE_POINT</option> &mdash; named restore points created with the <link linkend="functions-admin-backup">pg_create_restore_point()</link> function.</para>

</listitem>

<listitem>

<para><option>XLOG_XACT_COMMIT</option> &mdash; commit records for transactions. These records are caused by the <xref linkend="sql-commit"> command.</para>

</listitem>

<listitem>

<para><option>XLOG_XACT_COMMIT_PREPARED</option> &mdash; commit records for transactions that were earlier prepared for a two-phase commit. These records are caused by the <xref linkend="sql-commit-prepared"> command.</para>

</listitem>

<listitem>

<para><option>XLOG_XACT_ABORT</option> &mdash; abort records for transactions. These records are caused by the <xref linkend="sql-rollback"> command.</para>

</listitem>

<listitem>

<para><option>XLOG_XACT_ABORT_PREPARED</option> &mdash; abort records for transactions that were earlier prepared for a two-phase commit. These records are caused by the <xref linkend="sql-rollback-prepared"> command.</para>

</listitem>

</itemizedlist>

<para>By default, <application>pg_xlogdump</application> prints timestamps only for COMMIT records.

</para>

</listitem>

</varlistentry>

<varlistentry>

<term><option>-S</option></term>

<listitem>

<para>

Print the timestamp of the first WAL record of the specified type found in the log segment file. This option is required if you are going to use <option>-E</option> or <option>-F</option> options.</para>

<para>By default, <application>pg_xlogdump</application> prints timestamps only for COMMIT records. You can specify other record types using the <option>-F</option> option.

</para>

</listitem>

</varlistentry>

</variablelist>

</para>

</refsect1>

<refsect1>

<title>Notes</title>

<para>

Can give wrong results when the server is running.

<application>pg_xlogdump</> can give wrong results when the server is running.

</para>

<para>

<para>

<application>pg_xlogdump</> cannot read WAL files with suffix

<literal>.partial</>. Ifthose files need to be read, <literal>.partial</>

suffix needs to be removedfrom thefile name.

<literal>.partial</>. Ifsuch files need to be read, <literal>.partial</>

remove the suffixfrom thefilename.

</para>

</refsect1>