Re: Reliable and fast money transaction design

[Andrew Sullivan <ajs(at)crankycanuck(dot)ca>]

On Thu, Aug 30, 2007 at 03:32:40PM -0400, Tom Lane wrote:
> difference is that SERIALIZABLE takes one snapshot at transaction start
> and works with that for the whole transaction, whereas READ COMMITTED
> takes a new snap for each statement.

Oh, I get it.  This explains then why in principle READ COMMITTED
oughta be faster in the absence of conflicts: additional snapshot
checks are not needed?  (Sorry to be obtuse.  I think I had a
backward mental picture of how this worked: like SERIALIZABLE did
everything RC did, and then threw stuff away, or in any case did
additional work to ensure a nearly-mathematical serializability.)

A

-- 
Andrew Sullivan  | ajs(at)crankycanuck(dot)ca
"The year's penultimate month" is not in truth a good way of saying
November.
		--H.W. Fowler