| From: | Jeff Janes <jeff(dot)janes(at)gmail(dot)com> |
|---|---|
| To: | Andrew Gierth <andrew(at)tao11(dot)riddles(dot)org(dot)uk> |
| Cc: | Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us>, Andres Freund <andres(at)2ndquadrant(dot)com>, pgsql-hackers <pgsql-hackers(at)postgresql(dot)org> |
| Subject: | Re: procost for to_tsvector |
| Date: | 2015-03-11 22:22:24 |
| Message-ID: | CAMkU=1xX_EMv2OXqM=_fA9mTFwZA-L8qrn1onFvYE_toVtG+KA@mail.gmail.com |
| Views: | Raw Message | Whole Thread | Download mbox | Resend email |
| Thread: | |
| Lists: | pgsql-hackers |
On Wed, Mar 11, 2015 at 2:54 PM, Andrew Gierth <andrew(at)tao11(dot)riddles(dot)org(dot)uk>
wrote:
> Seq Scan on comments (cost=0.00..2406.18 rows=4140 width=792) (actual
> time=0.601..3946.589 rows=4056 loops=1)
>
> Bitmap Heap Scan on comments (cost=204.09..2404.30 rows=4140 width=792)
> (actual time=2.401..11.564 rows=4056 loops=1)
>
...
> (strangely, the seqscan plan is picked despite having a cost more than a
> point higher? what's up with that?)
>
It is probably this, from src/backend/optimizer/util/pathnode.c :
costcmp = compare_path_costs_fuzzily(new_path, old_path, 1.01,
parent_rel->consider_startup);
Cheers,
Jeff
| From | Date | Subject | |
|---|---|---|---|
| Next Message | Peter Geoghegan | 2015-03-11 22:57:48 | Re: Documentation of bt_page_items()'s ctid field |
| Previous Message | Kevin Grittner | 2015-03-11 22:19:39 | Re: Precedence of standard comparison operators |