| From: | Dmitry Dolgov <9erthalion6(at)gmail(dot)com> |
|---|---|
| To: | Stepan Yankevych <Stepan_Yankevych(at)epam(dot)com> |
| Cc: | "stepya(at)ukr(dot)net" <stepya(at)ukr(dot)net>, "pgsql-bugs(at)lists(dot)postgresql(dot)org" <pgsql-bugs(at)lists(dot)postgresql(dot)org> |
| Subject: | Re: BUG #16089: Index only scan does not happen but expected |
| Date: | 2019-10-30 15:14:39 |
| Message-ID: | 20191030151439.gtfp77bef25za3n4@localhost |
| Views: | Raw Message | Whole Thread | Download mbox | Resend email |
| Thread: | |
| Lists: | pgsql-bugs |
> On Wed, Oct 30, 2019 at 04:10:06PM +0100, Dmitry Dolgov wrote:
> > On Wed, Oct 30, 2019 at 02:18:09PM +0000, Stepan Yankevych wrote:
> >
> > >> And in fact at least in my tests this was indeed faster
> > Can you show execution plan when index is used?
> > Does it uses Index only scan or index scan and table scan?
>
> Yes, at the bottom of the plan there was an Index Only Scan going
> through l1_snapshot_201811 (although while populating the table I've set
> values only for not nullable columns).
To clarify, Index Only Scan was there only after changing
random_page_cost/seq_page_cost. As I mentioned in the previous email,
original plan was also parallel seq scan.
| From | Date | Subject | |
|---|---|---|---|
| Next Message | Stepan Yankevych | 2019-10-30 15:27:42 | RE: BUG #16089: Index only scan does not happen but expected |
| Previous Message | Dmitry Dolgov | 2019-10-30 15:10:06 | Re: BUG #16089: Index only scan does not happen but expected |