Re: [PERFORM] inheritance: planning time vs children number vs column number

2011-03-01 Thread Tom Lane
I wrote: > Marc Cousin writes: >> Yes, for the same test case, with a bit of data in every partition and >> statistics up to date, planning time goes from 20 seconds to 125ms for the >> 600 >> children/1000 columns case. Which is of course more than acceptable. > [ scratches head ... ] Actual

Re: [PERFORM] inheritance: planning time vs children number vs column number

2011-03-01 Thread Marc Cousin
The Tuesday 01 March 2011 16:33:51, Tom Lane wrote : > Marc Cousin writes: > > Le mardi 01 mars 2011 07:20:19, Tom Lane a écrit : > >> It's worth pointing out that the only reason this effect is dominating > >> the runtime is that you don't have any statistics for these toy test > >> tables. If

Re: [PERFORM] inheritance: planning time vs children number vs column number

2011-03-01 Thread Tom Lane
Marc Cousin writes: > Le mardi 01 mars 2011 07:20:19, Tom Lane a écrit : >> It's worth pointing out that the only reason this effect is dominating >> the runtime is that you don't have any statistics for these toy test >> tables. If you did, the cycles spent using those entries would dwarf >> th

Re: [PERFORM] inheritance: planning time vs children number vs column number

2011-02-28 Thread Marc Cousin
Le mardi 01 mars 2011 07:20:19, Tom Lane a écrit : > Marc Cousin writes: > > The Monday 28 February 2011 16:35:37, Tom Lane wrote : > >> 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 ca

Re: [PERFORM] inheritance: planning time vs children number vs column number

2011-02-28 Thread Tom Lane
Marc Cousin writes: > The Monday 28 February 2011 16:35:37, Tom Lane wrote : >> 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 leng

Re: [PERFORM] inheritance: planning time vs children number vs column number

2011-02-28 Thread Marc Cousin
The Monday 28 February 2011 16:35:37, Tom Lane wrote : > Marc Cousin 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 > >>

Re: [PERFORM] inheritance: planning time vs children number vs column number

2011-02-28 Thread Tom Lane
Marc Cousin 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) behav

Re: [PERFORM] inheritance: planning time vs children number vs column number

2011-02-28 Thread Marc Cousin
The Monday 28 February 2011 13:57:45, Heikki Linnakangas wrote : > On 28.02.2011 11:38, Marc Cousin wrote: > > I've been facing a very large (more than 15 seconds) planning time in a > > partitioned configuration. The amount of partitions wasn't completely > > crazy, around 500, not in the thousand

Re: [PERFORM] inheritance: planning time vs children number vs column number

2011-02-28 Thread Heikki Linnakangas
On 28.02.2011 11:38, Marc Cousin wrote: I've been facing a very large (more than 15 seconds) planning time in a partitioned configuration. The amount of partitions wasn't completely crazy, around 500, not in the thousands. The problem was that there were nearly 1000 columns in the parent table (v