Marc Cousin <cousinmarc@xxxxxxxxx> writes: > The Monday 28 February 2011 13:57:45, Heikki Linnakangas wrote : >> Testing here with a table with 1000 columns and 100 partitions, about >> 80% of the planning time is looking up the statistics on attribute >> width, to calculate average tuple width. I don't see O(n^2) behavior, >> though, it seems linear. > It is only based on experimentation, for my part, of courseâ?¦ > If you measure the planning time, modifying either the columns or the > partitions number, the square root of the planning time is almost perfectly > proportional with the parameter you're playing with. Could we see a concrete example demonstrating that? I agree with Heikki that it's not obvious what you are testing that would have such behavior. I can think of places that would have O(N^2) behavior in the length of the targetlist, but it seems unlikely that they'd come to dominate runtime at a mere 1000 columns. regards, tom lane -- Sent via pgsql-performance mailing list (pgsql-performance@xxxxxxxxxxxxxx) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-performance
