Re: loop with circular updates

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