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PostgreSQL documentation

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<command>pg_resetxlog</command>

<arg>-f</arg>

<arg>-n</arg>

<arg>-r</arg>

<arg>-o<replaceable class="parameter">oid</replaceable> </arg>

<arg>-x <replaceable class="parameter">xid</replaceable> </arg>

<arg>-m <replaceable class="parameter">mxid</replaceable> </arg>

<para>

If <command>pg_resetxlog</command> complains that it cannot determine

valid data for <filename>pg_control</>, you can force it to proceed

anywayby specifying the <literal>-f</> (force) switch. In this case

plausiblevalues will be substituted for the missing data.

<command>pg_resetxlog</command>'s own environment is the sourcefor

its guess at the locale fields; take care that <envar>LANG</>andso

forth match the environment that <command>initdb</> was run in.

WAL starting address, and databaselocale fields. Because determined

values might be wrong,thefirst five of these can be set using the

switches discussed below.If you are not able to determine correct

values for all these fields,<literal>-f</> can still be used, but

valid data for <filename>pg_control</>, you can force it to proceed anyway

by specifying the <literal>-f</> (force) switch.In this case plausible

values will be substituted for the missing data. Most of the fields can be

expected to match, but manual assistance may be neededfor the next OID,

next transaction ID, next multitransaction IDandoffset,

WAL starting address, and database locale fields.

guess at thelocale fields; take care that <envar>LANG</> and so forth

matchtheenvironment that <command>initdb</> was run in.

If you are not able to determine correct values for all these fields,

<literal>-f</> can still be used, but

the recovered database must be treated with even more suspicion than

usual: an immediate dump and reload is imperative. <emphasis>Do

not</>execute any data-modifying operations in the database before

you dump;as any such action is likely to make the corruption worse.

usual: an immediate dump and reload is imperative.<emphasis>Do not</>

execute any data-modifying operations in the database before you dump;

as any such action is likely to make the corruption worse.

</para>

<para>

</itemizedlist>

</para>

<para>

The <literal>-r</> restores <filename>pg_control</> counters listed

above without resetting the write-ahead log.

</para>

<para>

The <literal>-n</> (no operation) switch instructs

<command>pg_resetxlog</command> to print the values reconstructed from