Re: Issues with Quorum Commit

On 06.10.2010 01:14, Josh Berkus wrote:
> Last I checked, our goal with synch standby was to increase availablity,
> not decrease it.

No. Synchronous replication does not help with availability. It allows 
you to achieve zero data loss, ie. if the master dies, you are 
guaranteed that any transaction that was acknowledged as committed, is 
still committed.

The other use case is keeping a hot standby server (or servers) 
up-to-date, so that you can run queries against it and you are 
guaranteed to get the same results you would if you ran the query in the 
master.

Those are the two reasonable use cases I've seen. Anything else that has 
been discussed is some sort of a combination of those two, or something 
that doesn't make much sense when you scratch the surface and start 
looking at the failure modes.

--   Heikki Linnakangas  EnterpriseDB   http://www.enterprisedb.com