| From: | Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us> |
|---|---|
| To: | Matthew Churcher <matthew(dot)churcher(at)realvnc(dot)com> |
| Cc: | pgsql-general(at)postgresql(dot)org |
| Subject: | Re: Cost of initiating cursors |
| Date: | 2013-04-11 17:40:55 |
| Message-ID: | 6887.1365702055@sss.pgh.pa.us |
| Views: | Raw Message | Whole Thread | Download mbox | Resend email |
| Thread: | |
| Lists: | pgsql-general |
Matthew Churcher <matthew(dot)churcher(at)realvnc(dot)com> writes:
> I've tried cursor_tuple_fraction values as low as 0.0000000001 which by my reckoning should be low enough and also 0 but the planner is still selecting seqscan-and-sort.
Hm. Keep in mind that plpgsql caches query plans, so if you're
examining this by checking the runtime of the function you showed,
you'd need to start a fresh session, set cursor_tuple_fraction, then
try the function to be sure you were seeing the effects of the
parameter change.
regards, tom lane
| From | Date | Subject | |
|---|---|---|---|
| Next Message | François Beausoleil | 2013-04-11 19:46:21 | Re: PostgreSQL 9.1.8 Upgrade to 9.1.9 |
| Previous Message | Matthew Churcher | 2013-04-11 17:05:32 | Re: Cost of initiating cursors |