(moving to -hackers) On Wed, Jun 9, 2010 at 4:11 PM, Tom Lane <t...@sss.pgh.pa.us> wrote: > Robert Haas <robertmh...@gmail.com> writes: >> In going back through emails I had marked as possibly needing another >> look before 9.0 is released, I came across this issue again. As I >> understand it, analyze (or analyse) now collects statistics for both >> the parent individually, and for the parent and its children together. >> However, as I further understand it, autovacuum won't actually fire >> off an analyze unless there's enough activity on the parent table >> considered individually to warrant it. So if you have an empty parent >> and a bunch of children with data in it, your stats will still stink, >> unless you analyze by hand. > > Check. > >> Assuming my understanding of the problem is correct, we could: > >> (a) fix it, >> (b) document that you should consider periodic manual analyze commands >> in this situation, or >> (c) do nothing. > >> Thoughts? > > The objections to (a) are that it might result in excessive ANALYZE work > if not done intelligently, and that we haven't got a patch ready anyway. > I would have liked to get to this for 9.0 but I feel it's a bit late > now.
I guess I can't really disagree with that. Should we try to document this in some way? -- Robert Haas EnterpriseDB: http://www.enterprisedb.com The Enterprise Postgres Company -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
