diff options
| author | Bruce Momjian <bruce@momjian.us> | 2008-03-06 18:49:32 +0000 |
|---|---|---|
| committer | Bruce Momjian <bruce@momjian.us> | 2008-03-06 18:49:32 +0000 |
| commit | 2b70548bd448f206427050cf7c35f508001fec1b (patch) | |
| tree | 479e3141de3ae58f701427649cf9db9664073d56 | |
| parent | 4f887c6bf05dea2efdcedb5bd50aa4db9cdbff23 (diff) | |
Document use of pg_locks.objid for advisory locks, suggestion from Marc Mamin
| -rw-r--r-- | doc/src/sgml/catalogs.sgml | 7 | ||||
| -rw-r--r-- | doc/src/sgml/func.sgml | 5 |
2 files changed, 8 insertions, 4 deletions
diff --git a/doc/src/sgml/catalogs.sgml b/doc/src/sgml/catalogs.sgml index de045d7057d..8a16c77a7dd 100644 --- a/doc/src/sgml/catalogs.sgml +++ b/doc/src/sgml/catalogs.sgml @@ -1,4 +1,4 @@ -<!-- $PostgreSQL: pgsql/doc/src/sgml/catalogs.sgml,v 2.161 2008/01/31 18:40:02 tgl Exp $ --> +<!-- $PostgreSQL: pgsql/doc/src/sgml/catalogs.sgml,v 2.162 2008/03/06 18:49:32 momjian Exp $ --> <!-- Documentation of the system catalogs, directed toward PostgreSQL developers --> @@ -5691,7 +5691,10 @@ <entry>any OID column</entry> <entry> OID of the object within its system catalog, or NULL if the - object is not a general database object + object is not a general database object. + For advisory locks it is used to distinguish the two key + spaces (<literal>1</> for an int8 key, <literal>2</> for two + int4 keys). </entry> </row> <row> diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml index 056d12a1688..1052ab0d670 100644 --- a/doc/src/sgml/func.sgml +++ b/doc/src/sgml/func.sgml @@ -1,4 +1,4 @@ -<!-- $PostgreSQL: pgsql/doc/src/sgml/func.sgml,v 1.422 2008/03/03 18:09:02 momjian Exp $ --> +<!-- $PostgreSQL: pgsql/doc/src/sgml/func.sgml,v 1.423 2008/03/06 18:49:32 momjian Exp $ --> <chapter id="functions"> <title>Functions and Operators</title> @@ -12378,7 +12378,8 @@ SELECT (pg_stat_file('filename')).modification; <para> <function>pg_advisory_lock</> locks an application-defined resource, which can be identified either by a single 64-bit key value or two - 32-bit key values (note that these two key spaces do not overlap). If + 32-bit key values (note that these two key spaces do not overlap). + The key type is specified in <literal>pg_locks.objid</>. If another session already holds a lock on the same resource, the function will wait until the resource becomes available. The lock is exclusive. Multiple lock requests stack, so that if the same resource |