On Mon, 2007-11-05 at 11:58 +0530, Gokulakannan Somasundaram wrote: > The idea was to write a syncpoint every N seconds where we > record the > time and a snapshot of what's in progress. > > What exactly is getting recorded here? Will the Syncpoint be similar > to the Undo Log at distinct intervals?
Postgres needs to record the snapshot to allow visibility checks. There is no Undo log; the database records themselves represent the logical equivalent of an Undo log in other databases. But as I said, I'm not working on this, so I'm not going into detailed design anytime soon. -- Simon Riggs 2ndQuadrant http://www.2ndQuadrant.com ---------------------------(end of broadcast)--------------------------- TIP 9: In versions below 8.0, the planner will ignore your desire to choose an index scan if your joining column's datatypes do not match
