Update of /home/cvsd/slony1/slony1-engine/src/backend
In directory main.slony.info:/tmp/cvs-serv8627/src/backend

Modified Files:
	slony1_funcs.sql 
Log Message:
Reduce the quantity of spurious events generated:

1.  generate_sync_event() only needs to generate a SYNC on a node
    that is the origin for a set

2.  sync thread generates a SYNC when it starts; in later iterations,
    it will only generate a SYNC for its node if that node is the origin
    for a replication set

Per discussions with Jan Wieck on 2007-02-09; this seemed an experiment
worth trying.  I tried it, and the tests run fine, so I'm committing this.


Index: slony1_funcs.sql
===================================================================
RCS file: /home/cvsd/slony1/slony1-engine/src/backend/slony1_funcs.sql,v
retrieving revision 1.104
retrieving revision 1.105
diff -C2 -d -r1.104 -r1.105
*** slony1_funcs.sql	8 Feb 2007 18:01:15 -0000	1.104
--- slony1_funcs.sql	14 Mar 2007 15:59:32 -0000	1.105
***************
*** 5223,5227 ****
  	if not found then
  		-- If there has been no SYNC in the last interval, then push one
! 		perform @NAMESPACE at .createEvent(''_ at CLUSTERNAME@'', ''SYNC'', NULL);
  		return 1;
  	else
--- 5223,5229 ----
  	if not found then
  		-- If there has been no SYNC in the last interval, then push one
! 		perform @NAMESPACE at .createEvent(''_ at CLUSTERNAME@'', ''SYNC'', NULL) 
!                                          from @NAMESPACE at .sl_node n where no_id = @NAMESPACE at .getLocalNodeId(''_ at CLUSTERNAME@'') 
! 			and exists (select 1 from @NAMESPACE at .sl_set where set_origin = no_id);
  		return 1;
  	else
***************
*** 5232,5236 ****
  
  comment on function @NAMESPACE at .generate_sync_event(interval) is
!   'Generate a sync event if there has not been one in the requested interval.';
  
  -- ----------------------------------------------------------------------
--- 5234,5238 ----
  
  comment on function @NAMESPACE at .generate_sync_event(interval) is
!   'Generate a sync event if there has not been one in the requested interval, and this is a provider node.';
  
  -- ----------------------------------------------------------------------