On Mon, 22 Apr 2002 14:15:37 -0700 "Dann Corbit" <[EMAIL PROTECTED]> wrote: > From here: > http://osdb.sourceforge.net/ > We find this quote: > "For you long-suffering OSDB PostgreSQL users, we offer > > --postgresql=no_hash_index > > to work around the hash index problems of OSDB with PostgreSQL V7.1 and > 7.2. As always, let us know of any problems. May the source be with > you!" > > Does anyone know what the above is all about?
Yes -- search the list archives, or check the PostgreSQL docs. This problem has been brought up several times: hash indexes deadlock under concurrent load. A run of pgbench with a reasonably high concurrency level (10 or 15) produces the problem consistently. Previously, I had volunteered to fix this, but (a) I'm busy with the PREPARE/EXECUTE stuff at the moment. (b) I'm not sure it's worth the investment of time: AFAIK, hash indexes don't have many advantages over btrees for scalar data. On the other hand, if someone steps forward with some data on a specific advantage that hash indexes have over btrees, I don't expect that the concurrency problems should be too difficult to solve. Cheers, Neil -- Neil Conway <[EMAIL PROTECTED]> PGP Key ID: DB3C29FC ---------------------------(end of broadcast)--------------------------- TIP 3: if posting/reading through Usenet, please send an appropriate subscribe-nomail command to [EMAIL PROTECTED] so that your message can get through to the mailing list cleanly