Horton

Re: Proposal: Improve bitmap costing for lossy pages

Robert Haas <robertmhaas@gmail.com>

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From: Robert Haas <robertmhaas@gmail.com>
To: Dilip Kumar <dilipbalaut@gmail.com>
Cc: Alexander Kumenkov <a.kuzmenkov@postgrespro.ru>, pgsql-hackers <pgsql-hackers@postgresql.org>
Date: 2017-10-06T13:06:08Z
Lists: pgsql-hackers 
On Fri, Oct 6, 2017 at 2:12 AM, Dilip Kumar <dilipbalaut@gmail.com> wrote:
>> The performance results look good, but that's a slightly different
>> thing from whether the estimate is accurate.
>>
>> +    nbuckets = tbm_calculate_entires(maxbytes);
>>
>> entires?
>
> changed to
> + tbm->maxentries = (int) tbm_calculate_entires(maxbytes);

My point was not that you should add a cast, but that you wrote
"entires" rather than "entries".

-- 
Robert Haas
EnterpriseDB: http://www.enterprisedb.com
The Enterprise PostgreSQL Company

Commits

  1. Account for the effect of lossy pages when costing bitmap scans.