On 2013-07-19 10:40:01 +0530, Hari Babu wrote: > > On Friday, July 19, 2013 4:11 AM Greg Smith wrote: > >On 7/9/13 12:09 AM, Amit Kapila wrote: > >> I think the first thing to verify is whether the results posted can be > >> validated in some other environment setup by another person. > >> The testcase used is posted at below link: > >> http://www.postgresql.org/message-id/51366323.8070...@vmware.com > > >That seems easy enough to do here, Heikki's test script is excellent. > >The latest patch Hari posted on July 2 has one hunk that doesn't apply > >anymore now. > > The Head code change from Heikki is correct. > During the patch rebase to latest PG LZ optimization code, the above code > change is missed. > > Apart from the above changed some more changes are done in the patch, those > are.
FWIW I don't like this approach very much: * I'd be very surprised if this doesn't make WAL replay of update heavy workloads slower by at least factor of 2. * It makes data recovery from WAL *noticeably* harder since data corruption now is carried forwards and you need the old data to decode new data * It makes changeset extraction either more expensive or it would have to be disabled there. I think my primary issue is that philosophically/architecturally I am of the opinion that a wal record should make sense of it's own without depending on heap data. And this patch looses that. Greetings, Andres -- Andres Freund http://www.2ndQuadrant.com/ PostgreSQL Development, 24x7 Support, Training & Services -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
