On Wed, Aug 29, 2007 at 08:37:26AM -0500, Ron Johnson wrote: > -----BEGIN PGP SIGNED MESSAGE----- > Hash: SHA1 > > On 08/29/07 07:27, cluster wrote: > > OK, thanks. But what with the second question in which the UPDATE is > > based on a SELECT max(...) statement on another table? How can I ensure > > that no other process inserts a row between my SELECT max() and UPDATE - > > making my SELECT max() invalid? > > > > A table lock could be an option but I am only interested in blocking for > > row insertions for this particular account_id. Insertions for other > > account_ids will not make the SELECT max() invalid and should therefore > > be allowed. > > Well, concurrency and transactional consistency *allows* other > processes to update the table after you start your transaction. You > just won't *see* their updates while you're inside of a transaction. Just make sure and read up about transaction isolation... in the default of READ COMMITTED mode, you can sometimes see changes made by other transactions. -- Decibel!, aka Jim Nasby decibel@xxxxxxxxxxx EnterpriseDB http://enterprisedb.com 512.569.9461 (cell)
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