Jeff Amiel <jamiel@istreamimaging.com> writes:
> I thought:
> "Each transaction sees a snapshot (database version) as of its
> starttime, no matter what other transactions are doing while it runs"
That's a correct statement in SERIALIZABLE mode, but in the default
READ COMMITTED mode, it's more complicated --- a new snapshot is taken
for each command within a transaction. See the docs.
regards, tom lane