Re: [HACKERS] WIP: [[Parallel] Shared] Hash - Mailing list pgsql-hackers

From Thomas Munro
Subject Re: [HACKERS] WIP: [[Parallel] Shared] Hash
Date
Msg-id CAEepm=3Og-7-b3WOkiT=c+6y3eZ0VVSyb1K+SOvF17BO5KAt0A@mail.gmail.com
Whole thread Raw
In response to Re: [HACKERS] WIP: [[Parallel] Shared] Hash  (Rafia Sabih <rafia.sabih@enterprisedb.com>)
Responses Re: [HACKERS] WIP: [[Parallel] Shared] Hash  (Thomas Munro <thomas.munro@enterprisedb.com>)
List pgsql-hackers
On Mon, Mar 13, 2017 at 8:40 PM, Rafia Sabih
<rafia.sabih@enterprisedb.com> wrote:
> In an attempt to test v7 of this patch on TPC-H 20 scale factor I found a
> few regressions,
> Q21: 52 secs on HEAD and  400 secs with this patch

Thanks Rafia.  Robert just pointed out off-list that there is a bogus
0 row estimate in here:

->  Parallel Hash Semi Join  (cost=1006599.34..1719227.30 rows=0
width=24) (actual time=38716.488..100933.250 rows=7315896 loops=5)

Will investigate, thanks.

> Q8: 8 secs on HEAD to 14 secs with patch

Also looking into this one.

-- 
Thomas Munro
http://www.enterprisedb.com



pgsql-hackers by date:

Previous
From: Tom Lane
Date:
Subject: Re: [HACKERS] PATCH: Configurable file mode mask
Next
From: Heikki Linnakangas
Date:
Subject: Re: [HACKERS] Radix tree for character conversion