diff options
Diffstat (limited to 'doc/src')
| -rw-r--r-- | doc/src/sgml/pgvisibility.sgml | 28 |
1 files changed, 27 insertions, 1 deletions
diff --git a/doc/src/sgml/pgvisibility.sgml b/doc/src/sgml/pgvisibility.sgml index 48b003d1516..4cdca7dada9 100644 --- a/doc/src/sgml/pgvisibility.sgml +++ b/doc/src/sgml/pgvisibility.sgml @@ -32,7 +32,8 @@ Functions which display information about <literal>PD_ALL_VISIBLE</> are much more costly than those which only consult the visibility map, because they must read the relation's data blocks rather than only the - (much smaller) visibility map. + (much smaller) visibility map. Functions that check the relation's + data blocks are similarly expensive. </para> <sect2> @@ -92,6 +93,31 @@ </para> </listitem> </varlistentry> + + <varlistentry> + <term><function>pg_check_frozen(regclass, t_ctid OUT tid) returns setof tid</function></term> + + <listitem> + <para> + Returns the TIDs of non-frozen tuples present in pages marked all-frozen + in the visibility map. If this function returns a non-empty set of + TIDs, the database is corrupt. + </para> + </listitem> + </varlistentry> + + <varlistentry> + <term><function>pg_check_visible(regclass, t_ctid OUT tid) returns setof tid</function></term> + + <listitem> + <para> + Returns the TIDs of tuples which are not all-visible despite the fact + that the pages which contain them are marked as all-visible in the + visibility map. If this function returns a non-empty set of TIDs, the + database is corrupt. + </para> + </listitem> + </varlistentry> </variablelist> <para> |