| From: | Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us> |
|---|---|
| To: | emre(at)hasegeli(dot)com |
| Cc: | Oleksii Kliukin <alexk(at)hintbits(dot)com>, Álvaro Herrera <alvherre(at)alvh(dot)no-ip(dot)org>, PostgreSQL-development <pgsql-hackers(at)postgresql(dot)org> |
| Subject: | Re: rows estimate in explain analyze for the BRIN index |
| Date: | 2015-12-30 17:44:40 |
| Message-ID: | 18658.1451497480@sss.pgh.pa.us |
| Views: | Raw Message | Whole Thread | Download mbox | Resend email |
| Thread: | |
| Lists: | pgsql-hackers |
Emre Hasegeli <emre(at)hasegeli(dot)com> writes:
>> which is much closer to the actual number of rows removed by the index
>> recheck + the one left.
> Is it better to be closer? We are saying those are the "actual"
> values not the estimates. If we cannot provide the actual rows, I
> think it is better to provide nothing.
Return zero you mean? Good point; there's precedent for that elsewhere
in EXPLAIN ANALYZE, IIRC. If we do what I propose in my patch, it would
possibly just lead to more questions like Oleksii's, because people would
be even more likely to believe that the number is accurate.
regards, tom lane
| From | Date | Subject | |
|---|---|---|---|
| Next Message | Andres Freund | 2015-12-30 17:44:54 | Re: Some 9.5beta2 backend processes not terminating properly? |
| Previous Message | Andres Freund | 2015-12-30 17:42:14 | Re: Some 9.5beta2 backend processes not terminating properly? |