diff options
Diffstat (limited to 'doc')
| -rw-r--r-- | doc/src/sgml/func.sgml | 27 |
1 files changed, 26 insertions, 1 deletions
diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml index cb0a36a170f..6d7c7b8e0d0 100644 --- a/doc/src/sgml/func.sgml +++ b/doc/src/sgml/func.sgml @@ -15747,7 +15747,7 @@ SELECT * FROM pg_ls_dir('.') WITH ORDINALITY AS t(ls,n); <row> <entry><literal><function>pg_blocking_pids(<type>int</type>)</function></literal></entry> <entry><type>int[]</type></entry> - <entry>Process ID(s) that are blocking specified server process ID</entry> + <entry>Process ID(s) that are blocking specified server process ID from acquiring a lock</entry> </row> <row> @@ -15794,6 +15794,12 @@ SELECT * FROM pg_ls_dir('.') WITH ORDINALITY AS t(ls,n); </row> <row> + <entry><literal><function>pg_safe_snapshot_blocking_pids(<type>int</type>)</function></literal></entry> + <entry><type>int[]</type></entry> + <entry>Process ID(s) that are blocking specified server process ID from acquiring a safe snapshot</entry> + </row> + + <row> <entry><literal><function>pg_trigger_depth()</function></literal></entry> <entry><type>int</type></entry> <entry>current nesting level of <productname>PostgreSQL</> triggers @@ -16068,6 +16074,25 @@ SET search_path TO <replaceable>schema</> <optional>, <replaceable>schema</>, .. </para> <indexterm> + <primary>pg_safe_snapshot_blocking_pids</primary> + </indexterm> + + <para> + <function>pg_safe_snapshot_blocking_pids</function> returns an array of + the process IDs of the sessions that are blocking the server process with + the specified process ID from acquiring a safe snapshot, or an empty array + if there is no such server process or it is not blocked. A session + running a <literal>SERIALIZABLE</literal> transaction blocks + a <literal>SERIALIZABLE READ ONLY DEFERRABLE</literal> transaction from + acquiring a snapshot until the latter determines that it is safe to avoid + taking any predicate locks. See <xref linkend="xact-serializable"> for + more information about serializable and deferrable transactions. Frequent + calls to this function could have some impact on database performance, + because it needs access to the predicate lock manager's shared + state for a short time. + </para> + + <indexterm> <primary>version</primary> </indexterm> |