On 14/09/10 19:34, Kevin Grittner wrote:
Attached is the latest Serializable Snapshot Isolation (SSI) patch.
Great work! A year ago I thought it would be impossible to have a true serializable mode in PostgreSQL because of the way we do MVCC, and now we have a patch.
At a quick read-through, the code looks very tidy and clear now. Some comments:
Should add a citation to Cahill's work this is based on. Preferably with a hyperlink. A short description of how the predicate locks help to implement serializable mode would be nice too. I haven't read Cahill's papers, and I'm left wondering what the RW conflicts and dependencies are, when you're supposed to grab predicate locks etc.
If a page- or relation level SILOCK is taken, is it possible to get false conflicts? Ie. a transaction is rolled back because it modified a tuple on a page where some other transaction modified another tuple, even though there's no dependency between the two.
-- Heikki Linnakangas EnterpriseDB http://www.enterprisedb.com -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
