Re: rows estimate in explain analyze for the BRIN index - Mailing list pgsql-hackers

From Tom Lane
Subject Re: rows estimate in explain analyze for the BRIN index
Date
Msg-id 18658.1451497480@sss.pgh.pa.us
Whole thread Raw
In response to Re: rows estimate in explain analyze for the BRIN index  (Emre Hasegeli <emre@hasegeli.com>)
List pgsql-hackers
Emre Hasegeli <emre@hasegeli.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



pgsql-hackers by date:

Previous
From: Andres Freund
Date:
Subject: Re: Some 9.5beta2 backend processes not terminating properly?
Next
From: Andres Freund
Date:
Subject: Re: Some 9.5beta2 backend processes not terminating properly?