<table id="functions-data-sanity-table">

<title>Data Sanity Functions</title>

<tgroup cols="3">

<tgroup cols="1">

<thead>

<row><entry>Name</entry> <entry>Return Type</entry> <entry>Description</entry>

<row>

<entry role="func_table_entry"><para role="func_signature">

Function

</para>

<para>

Description

</para></entry>

</row>

</thead>

<tbody>

<row>

<entry>

<literal><function>pg_relation_check_pages(<parameter>relation</parameter> <type>regclass</type> [, <parameter>fork</parameter> <type>text</type> <literal>DEFAULT</literal> <literal>NULL</literal> ])</function></literal>

</entry>

<entry><type>setof record</type></entry>

<entry>Check the pages of a relation.

</entry>

<entry role="func_table_entry"><para role="func_signature">

<indexterm>

<primary>pg_relation_check_pages</primary>

</indexterm>

<function>pg_relation_check_pages</function> ( <parameter>relation</parameter> <type>regclass</type> [, <parameter>fork</parameter> <type>text</type> ] )

<returnvalue>setof record</returnvalue>

( <parameter>path</parameter> <type>text</type>,

<parameter>failed_block_num</parameter> <type>bigint</type> )

</para>

<para>

Checks the pages of the specified relation to see if they are valid

enough to safely be loaded into the server's shared buffers. If

given, <parameter>fork</parameter> specifies that only the pages of

the given fork are to be verified. <parameter>fork</parameter> can

be <literal>main</literal> for the main data

fork, <literal>fsm</literal> for the free space

map, <literal>vm</literal> for the visibility map,

or <literal>init</literal> for the initialization fork. The

default of <literal>NULL</literal> means that all forks of the

relation should be checked. The function returns a list of block

numbers that appear corrupted along with the path names of their

files. Use of this function is restricted to superusers by

default, but access may be granted to others

using <command>GRANT</command>.

</para></entry>

</row>

</tbody>

</tgroup>

</table>

<indexterm>

<primary>pg_relation_check_pages</primary>

</indexterm>

<para id="functions-check-relation-note" xreflabel="pg_relation_check_pages">

<function>pg_relation_check_pages</function> iterates over all blocks of a

given relation and verifies if they are in a state where they can safely

be loaded into the shared buffers. If defined,

<replaceable>fork</replaceable> specifies that only the pages of the given

fork are to be verified. Fork can be <literal>'main'</literal> for the

main data fork, <literal>'fsm'</literal> for the free space map,

<literal>'vm'</literal> for the visibility map, or

<literal>'init'</literal> for the initialization fork. The default of

<literal>NULL</literal> means that all the forks of the relation are

checked. The function returns a list of blocks that are considered as

corrupted with the path of the related file. Use of this function is

restricted to superusers by default but access may be granted to others

using <command>GRANT</command>.

</para>

</sect2>

</sect1>