Tom,
Yes, I see. good to get that straightened out in my head, thank you.
-Meghan
Tom Lane
<tgl@sss.pgh.pa.u
s> To
Jessica M Salmon
07/28/2006 09:46 <jmsalmon@fs.fed.us>
AM cc
pgsql-general@postgresql.org
Subject
Re: [GENERAL] loop with circular
updates
Jessica M Salmon <jmsalmon@fs.fed.us> writes:
> -is it true that when looping over query results in a plpgsql
> for..in..execute loop, several records are stored in memory at one time?
Yes, but that's got nothing to do with your issue.
> -if I then update one of the records currently in memory, are these
> changes visible when the loop gets to it?
*All* queries in Postgres see a snapshot as of the instant of query
start. This is a property of the MVCC rules and has nothing to do with
buffering. What's returned by a FOR IN EXECUTE is whatever was in the
database when the loop began.
regards, tom lane
