Re: Performance degradation in Bitmapscan (commit 75ae538bc3168bf44475240d4e0487ee2f3bb376)

On Wed, Nov 23, 2016 at 3:33 AM, Andres Freund <andres(at)anarazel(dot)de> wrote:
> On 2016-11-18 08:00:40 -0500, Robert Haas wrote:
>> On Tue, Nov 15, 2016 at 2:28 PM, Andres Freund <andres(at)anarazel(dot)de> wrote:
>> > I've a working fix for this, and for a similar issue Robert found. I'm
>> > still playing around with it, but basically the fix is to make the
>> > growth policy a bit more adaptive.
>>
>> Any chance you can post a patch soon?
>
> Here's my WIP series addressing this and related problems. With this
> we're again noticeably faster than the dynahash implementation, in both
> the case here, and the query you brought up over IM.
>
> This definitely needs some more TLC, but the general approach seems
> good. I particularly like that it apparently allows us to increase the
> default fillfactor without much downside according to my measurements.

Are you going to commit something here? At least enough to make
Finalize HashAgg -> Gather -> Partial HashAgg terminate in finite
time? Because the fact that it doesn't really sucks.

--
Robert Haas
EnterpriseDB: http://www.enterprisedb.com
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