| From: | Justin Pryzby <pryzby(at)telsasoft(dot)com> |
|---|---|
| To: | pgsql-hackers(at)lists(dot)postgresql(dot)org |
| Cc: | Jeff Janes <jeff(dot)janes(at)gmail(dot)com> |
| Subject: | Re: allow disabling indexscans without disabling bitmapscans |
| Date: | 2020-01-04 19:34:16 |
| Message-ID: | 20200104193416.GX12066@telsasoft.com |
| Views: | Raw Message | Whole Thread | Download mbox | Resend email |
| Thread: | |
| Lists: | pgsql-hackers pgsql-performance |
On Sat, Jan 04, 2020 at 10:50:47AM -0600, Justin Pryzby wrote:
> > Doesn't enable_indexscan=off accomplish this already? It is possible but
> > not terribly likely to switch from index to seq, rather than from index to
> > bitmap. (Unless the index scan was being used to obtain an ordered result,
> > but a hypothetical enable_bitmapscan=FORCE can't fix that).
>
> No, enable_indexscan=off implicitly disables bitmap index scans, since it does:
I don't know how I went wrong, but the regress tests clued me in..it's as Jeff
said.
Sorry for the noise.
Justin
| From | Date | Subject | |
|---|---|---|---|
| Next Message | Tom Lane | 2020-01-04 19:50:47 | Re: pgsql: Add basic TAP tests for psql's tab-completion logic. |
| Previous Message | Dean Rasheed | 2020-01-04 19:08:54 | Re: Greatest Common Divisor |
| From | Date | Subject | |
|---|---|---|---|
| Next Message | Justin Pryzby | 2020-01-06 02:56:23 | doc: alter table references bogus table-specific planner parameters |
| Previous Message | Justin Pryzby | 2020-01-04 16:50:47 | allow disabling indexscans without disabling bitmapscans |