<indexterm>
<primary>pg_create_restore_point</primary>
</indexterm>
+ <indexterm>
+ <primary>pg_current_xlog_flush_location</primary>
+ </indexterm>
<indexterm>
<primary>pg_current_xlog_insert_location</primary>
</indexterm>
<entry><type>pg_lsn</type></entry>
<entry>Create a named point for performing restore (restricted to superusers)</entry>
</row>
+ <row>
+ <entry>
+ <literal><function>pg_current_xlog_flush_location()</function></literal>
+ </entry>
+ <entry><type>pg_lsn</type></entry>
+ <entry>Get current transaction log flush location</entry>
+ </row>
<row>
<entry>
<literal><function>pg_current_xlog_insert_location()</function></literal>
<function>pg_current_xlog_location</> displays the current transaction log write
location in the same format used by the above functions. Similarly,
<function>pg_current_xlog_insert_location</> displays the current transaction log
- insertion point. The insertion point is the <quote>logical</> end
- of the transaction log
- at any instant, while the write location is the end of what has actually
- been written out from the server's internal buffers. The write location
- is the end of what can be examined from outside the server, and is usually
+ insertion point and <function>pg_current_xlog_flush_location</> displays the
+ current transaction log flush point. The insertion point is the <quote>logical</>
+ end of the transaction log at any instant, while the write location is the end of
+ what has actually been written out from the server's internal buffers and flush
+ location is the location guaranteed to be written to durable storage. The write
+ location is the end of what can be examined from outside the server, and is usually
what you want if you are interested in archiving partially-complete transaction log
- files. The insertion point is made available primarily for server
+ files. The insertion and flush points are made available primarily for server
debugging purposes. These are both read-only operations and do not
require superuser permissions.
</para>
PG_RETURN_LSN(current_recptr);
}
+/*
+ * Report the current WAL flush location (same format as pg_start_backup etc)
+ *
+ * This function is mostly for debugging purposes.
+ */
+Datum
+pg_current_xlog_flush_location(PG_FUNCTION_ARGS)
+{
+ XLogRecPtr current_recptr;
+
+ if (RecoveryInProgress())
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("recovery is in progress"),
+ errhint("WAL control functions cannot be executed during recovery.")));
+
+ current_recptr = GetFlushRecPtr();
+
+ PG_RETURN_LSN(current_recptr);
+}
+
/*
* Report the last WAL receive location (same format as pg_start_backup etc)
*
extern Datum pg_create_restore_point(PG_FUNCTION_ARGS);
extern Datum pg_current_xlog_location(PG_FUNCTION_ARGS);
extern Datum pg_current_xlog_insert_location(PG_FUNCTION_ARGS);
+extern Datum pg_current_xlog_flush_location(PG_FUNCTION_ARGS);
extern Datum pg_last_xlog_receive_location(PG_FUNCTION_ARGS);
extern Datum pg_last_xlog_replay_location(PG_FUNCTION_ARGS);
extern Datum pg_last_xact_replay_timestamp(PG_FUNCTION_ARGS);
DESCR("current xlog write location");
DATA(insert OID = 2852 ( pg_current_xlog_insert_location PGNSP PGUID 12 1 0 0 0 f f f f t f v s 0 0 3220 "" _null_ _null_ _null_ _null_ _null_ pg_current_xlog_insert_location _null_ _null_ _null_ ));
DESCR("current xlog insert location");
+DATA(insert OID = 3330 ( pg_current_xlog_flush_location PGNSP PGUID 12 1 0 0 0 f f f f t f v s 0 0 3220 "" _null_ _null_ _null_ _null_ _null_ pg_current_xlog_flush_location _null_ _null_ _null_ ));
+DESCR("current xlog flush location");
DATA(insert OID = 2850 ( pg_xlogfile_name_offset PGNSP PGUID 12 1 0 0 0 f f f f t f i s 1 0 2249 "3220" "{3220,25,23}" "{i,o,o}" "{wal_location,file_name,file_offset}" _null_ _null_ pg_xlogfile_name_offset _null_ _null_ _null_ ));
DESCR("xlog filename and byte offset, given an xlog location");
DATA(insert OID = 2851 ( pg_xlogfile_name PGNSP PGUID 12 1 0 0 0 f f f f t f i s 1 0 25 "3220" _null_ _null_ _null_ _null_ _null_ pg_xlogfile_name _null_ _null_ _null_ ));