On 03/03/2011 03:49 PM, Jim Nasby wrote: > On Mar 2, 2011, at 2:54 PM, Joe Conway wrote: >> On 03/02/2011 12:41 PM, Tom Lane wrote: >>> Looks like the process trying to do the ALTER has already got some >>> lower-level lock on the table. It evidently hasn't got >>> AccessExclusiveLock, but nonetheless has something strong enough to >>> block an INSERT, such as ShareLock. >> >> Hmmm, is it possible that the following might do that, whereas a simple >> ALTER TABLE would not? > > Impossible to tell without seeing what's in the script... ie: if the script > was > > BEGIN; > -- Do something to that table that blocks inserts > SELECT change_column_type(...); > COMMIT; > > You'd get a deadlock.
The script was exactly the one posted, i.e. BEGIN; CREATE FUNCTION change_column_type(...); SELECT change_column_type(...); COMMIT; That's all there is to it. And the function itself has no specific reference to the table being altered. That's why I'm left scratching my head ;-) Joe -- Joe Conway credativ LLC: http://www.credativ.us Linux, PostgreSQL, and general Open Source Training, Service, Consulting, & 24x7 Support
signature.asc
Description: OpenPGP digital signature
