diff options
Diffstat (limited to 'doc/src')
| -rw-r--r-- | doc/src/sgml/catalogs.sgml | 37 | ||||
| -rw-r--r-- | doc/src/sgml/config.sgml | 11 |
2 files changed, 33 insertions, 15 deletions
diff --git a/doc/src/sgml/catalogs.sgml b/doc/src/sgml/catalogs.sgml index 525d24feace..68ff0921481 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 2.156 2007/09/03 00:39:11 tgl Exp $ --> +<!-- $PostgreSQL: pgsql/doc/src/sgml/catalogs.sgml,v 2.157 2007/09/05 18:10:47 tgl Exp $ --> <!-- Documentation of the system catalogs, directed toward PostgreSQL developers --> @@ -5147,7 +5147,7 @@ There are several distinct types of lockable objects: whole relations (e.g., tables), individual pages of relations, individual tuples of relations, - transaction IDs, + transaction IDs (both virtual and permanent IDs), and general database objects (identified by class OID and object OID, in the same way as in <structname>pg_description</structname> or <structname>pg_depend</structname>). Also, the right to extend a @@ -5178,6 +5178,7 @@ <literal>page</>, <literal>tuple</>, <literal>transactionid</>, + <literal>virtualxid</>, <literal>object</>, <literal>userlock</>, or <literal>advisory</> @@ -5220,6 +5221,15 @@ </entry> </row> <row> + <entry><structfield>virtualxid</structfield></entry> + <entry><type>text</type></entry> + <entry></entry> + <entry> + Virtual ID of a transaction, or NULL if the object is not a + virtual transaction ID + </entry> + </row> + <row> <entry><structfield>transactionid</structfield></entry> <entry><type>xid</type></entry> <entry></entry> @@ -5257,11 +5267,11 @@ </entry> </row> <row> - <entry><structfield>transaction</structfield></entry> - <entry><type>xid</type></entry> + <entry><structfield>virtualtransaction</structfield></entry> + <entry><type>text</type></entry> <entry></entry> <entry> - ID of the transaction that is holding or awaiting this lock + Virtual ID of the transaction that is holding or awaiting this lock </entry> </row> <row> @@ -5301,10 +5311,14 @@ </para> <para> - Every transaction holds an exclusive lock on its transaction ID for its - entire duration. If one transaction finds it necessary to wait specifically + Every transaction holds an exclusive lock on its virtual transaction ID for + its entire duration. If a permanent ID is assigned to the transaction + (which normally happens only if the transaction changes the state of the + database), it also holds an exclusive lock on its permanent transaction ID + until it ends. When one transaction finds it necessary to wait specifically for another transaction, it does so by attempting to acquire share lock on - the other transaction ID. That will succeed only when the other transaction + the other transaction ID (either virtual or permanent ID depending on the + situation). That will succeed only when the other transaction terminates and releases its locks. </para> @@ -5314,7 +5328,7 @@ and therefore row-level locks normally do not appear in this view. If a transaction is waiting for a row-level lock, it will usually appear in the view as waiting for the - transaction ID of the current holder of that row lock. + permanent transaction ID of the current holder of that row lock. </para> <para> @@ -5350,11 +5364,10 @@ </para> <para> - If you have enabled the statistics collector, the - <structfield>pid</structfield> column can be joined to the + The <structfield>pid</structfield> column can be joined to the <structfield>procpid</structfield> column of the <structname>pg_stat_activity</structname> view to get more - information on the session holding or waiting to hold the lock. + information on the session holding or waiting to hold each lock. Also, if you are using prepared transactions, the <structfield>transaction</> column can be joined to the <structfield>transaction</structfield> column of the diff --git a/doc/src/sgml/config.sgml b/doc/src/sgml/config.sgml index 5ef230a4fe3..d770c4606f2 100644 --- a/doc/src/sgml/config.sgml +++ b/doc/src/sgml/config.sgml @@ -1,4 +1,4 @@ -<!-- $PostgreSQL: pgsql/doc/src/sgml/config.sgml,v 1.141 2007/08/22 04:45:20 tgl Exp $ --> +<!-- $PostgreSQL: pgsql/doc/src/sgml/config.sgml,v 1.142 2007/09/05 18:10:47 tgl Exp $ --> <chapter Id="runtime-config"> <title>Server Configuration</title> @@ -2940,9 +2940,14 @@ SELECT * FROM parent WHERE key = 2400; <entry>no</entry> </row> <row> + <entry><literal>%v</literal></entry> + <entry>Virtual transaction ID (backendID/localXID)</entry> + <entry>no</entry> + </row> + <row> <entry><literal>%x</literal></entry> - <entry>Transaction ID</entry> - <entry>yes</entry> + <entry>Transaction ID (0 if none is assigned)</entry> + <entry>no</entry> </row> <row> <entry><literal>%q</literal></entry> |