From 5737c12df0581b3298e3e9586bdef170811ce176 Mon Sep 17 00:00:00 2001 From: Simon Riggs Date: Sat, 25 Mar 2017 14:07:27 +0000 Subject: Report catalog_xmin separately in hot_standby_feedback If the upstream walsender is using a physical replication slot, store the catalog_xmin in the slot's catalog_xmin field. If the upstream doesn't use a slot and has only a PGPROC entry behaviour doesn't change, as we store the combined xmin and catalog_xmin in the PGPROC entry. Author: Craig Ringer --- doc/src/sgml/protocol.sgml | 33 ++++++++++++++++++++++++++++----- 1 file changed, 28 insertions(+), 5 deletions(-) (limited to 'doc/src') diff --git a/doc/src/sgml/protocol.sgml b/doc/src/sgml/protocol.sgml index 48ca4140312..b3a50261c33 100644 --- a/doc/src/sgml/protocol.sgml +++ b/doc/src/sgml/protocol.sgml @@ -1916,10 +1916,11 @@ The commands accepted in walsender mode are: - The standby's current xmin. This may be 0, if the standby is - sending notification that Hot Standby feedback will no longer - be sent on this connection. Later non-zero messages may - reinitiate the feedback mechanism. + The standby's current global xmin, excluding the catalog_xmin from any + replication slots. If both this value and the following + catalog_xmin are 0 this is treated as a notification that Hot Standby + feedback will no longer be sent on this connection. Later non-zero + messages may reinitiate the feedback mechanism. @@ -1929,7 +1930,29 @@ The commands accepted in walsender mode are: - The standby's current epoch. + The epoch of the global xmin xid on the standby. + + + + + + Int32 + + + + The lowest catalog_xmin of any replication slots on the standby. Set to 0 + if no catalog_xmin exists on the standby or if hot standby feedback is being + disabled. + + + + + + Int32 + + + + The epoch of the catalog_xmin xid on the standby. -- cgit v1.2.3