From: | Simon Riggs <simon(at)2ndQuadrant(dot)com> |
---|---|
To: | Jinyu Zhang <beijing_pg(at)163(dot)com> |
Cc: | "pgsql-hackers(at)postgresql(dot)org" <pgsql-hackers(at)postgresql(dot)org> |
Subject: | Re: BRIN Scan: Optimize memory allocation in function 'bringetbitmap' |
Date: | 2015-09-28 14:07:02 |
Message-ID: | CANP8+jKX2xy3Cx0VGiM_vRx8sms4MWW-s-atZXCduJdKdPUrGw@mail.gmail.com |
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On 27 September 2015 at 02:15, Jinyu Zhang <beijing_pg(at)163(dot)com> wrote:
>
> BRIN Scan: Optimize memory allocation in function 'bringetbitmap'.
> We can allocate memory for some pointer before do long loop instead of
> allocating
> memory in long loop.
>
> Before optimizing code (warm run)
> postgres=# select count(*) from lineitem where l_orderkey=1;
> count
> -------
> 6
> (1 row)
>
> Time: 456.219 ms
>
> After optimizing code (warm run)
> postgres=# select count(*) from lineitem where l_orderkey=1;
> count
> -------
> 6
> (1 row)
>
> Time: 349.219 ms
>
Patch?
--
Simon Riggs http://www.2ndQuadrant.com/
<http://www.2ndquadrant.com/>
PostgreSQL Development, 24x7 Support, Remote DBA, Training & Services
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