On Mon, Feb 13, 2012 at 07:16:58PM -0300, Alvaro Herrera wrote: > Okay, so this patch fixes the truncation and wraparound issues through a > mechanism much like pg_clog's: it keeps track of the oldest possibly > existing multis on each and every table, and then during tuple freezing > those are removed. I also took the liberty to make the code remove > multis altogether (i.e. resetting the IS_MULTI hint bit) when only the > update remains and lockers are all gone. > > I also cleaned up the code in heapam so that there's a couple of tables > mapping MultiXactStatus to LockTupleMode and back, and to heavyweight > lock modes (the older patches used functions to do this, which was > pretty ugly). I had to add a little helper function to lock.c to make > this work. I made a rather large bunch of other minor changes to close > minor bugs here and there. > > Docs have been added, as have new tests for the isolation harness, which > I've ensured pass in both read committed and serializable modes; WAL > logging for locking updated versions of a tuple, when an old one is > locked due to an old snapshot, was also added; there's plenty of room > for growth in the MultiXact flag bits; the bit that made tables with no > keys lock the entire row all the time was removed; multiple places in > code comments were cleaned up that referred to this feature as "FOR KEY > LOCK" and ensured that it also mentions FOR KEY UPDATE; the pg_rowlocks, > pageinspect, pg_controldata, pg_resetxlog utilities have been updated.
All of the above sounds great. I especially like the growing test coverage. > All in all, I think this is in pretty much final shape. Only pg_upgrade > bits are still missing. If sharp eyes could give this a critical look > and knuckle-cracking testers could give it a spin, that would be > helpful. Lack of pg_upgrade support leaves this version incomplete, because that omission would constitute a blocker for beta 2. This version changes as much code compared to the version I reviewed at the beginning of the CommitFest as that version changed overall. In that light, it's time to close the books on this patch for the purpose of this CommitFest; I'm marking it Returned with Feedback. Thanks for your efforts thus far. On Mon, Jan 30, 2012 at 06:48:47PM -0500, Noah Misch wrote: > On Tue, Jan 24, 2012 at 03:47:16PM -0300, Alvaro Herrera wrote: > > * Columns that are part of the key > > Noah thinks the set of columns should only consider those actually > > referenced > > by keys, not those that *could* be referenced. > > Well, do you disagree? To me it's low-hanging fruit, because it isolates the > UPDATE-time overhead of this patch to FK-referenced tables rather than all > tables having a PK or PK-like index (often just "all tables"). You have not answered my question above. nm -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
