>>>>> "Chester" == Chester Kustarz <[EMAIL PROTECTED]> writes:
> On Wed, 28 Jan 2004, Chester Kustarz wrote: >> On Wed, 28 Jan 2004, Samuel Tardieu wrote: > If in a transaction I >> call an embedded function in Pl/PgSQL, in which > I have: >> > >> > delete from t where condition; > for e in select distinct on (f) >> * from t where ... loop > ... > end loop; >> > >> > Do I have the guarantee that, in any event, rows deleted from >> table t > by the delete won't reappear in the select result? >> >> i do not think you have that guarantee in READ COMMITTED mode >> because there is a slight possibility another backend sneaked a >> committed insert in between the delete and select >> statement. perhaps you want to change to SERIALIZABLE transaction >> isolation. or perhaps you would like to repeat the WHERE condition >> from the DELETE in the following SELECT so as to not gather any of >> the offending rows. >> >> http://www.postgresql.org/docs/7.4/static/sql-set-transaction.html > perhaps the isolation level applies to the statement that called the > function, in which case you would be ok. that would make more sense, > no? Yes. But the possible effect your describe (insertion of new rows after the DELETE statement and before the SELECT) matches accurately the symptoms we are observing. However, as we do have a lot of transactions, this is not easy to reproduce. Sam -- Samuel Tardieu -- [EMAIL PROTECTED] -- http://www.rfc1149.net/sam ---------------------------(end of broadcast)--------------------------- TIP 6: Have you searched our list archives? http://archives.postgresql.org
