| From: | Amit Kapila <amit(dot)kapila16(at)gmail(dot)com> |
|---|---|
| To: | Tatsuo Ishii <ishii(at)postgresql(dot)org> |
| Cc: | Amit Langote <Langote_Amit_f8(at)lab(dot)ntt(dot)co(dot)jp>, pgsql-hackers <pgsql-hackers(at)postgresql(dot)org> |
| Subject: | Re: BRIN INDEX value |
| Date: | 2015-09-04 08:40:52 |
| Message-ID: | CAA4eK1+R2snN09_7b9TVgY-Ke6T8Z+oZz+pVU5ULxofeWTo33w@mail.gmail.com |
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| Lists: | pgsql-hackers |
On Fri, Sep 4, 2015 at 10:03 AM, Tatsuo Ishii <ishii(at)postgresql(dot)org> wrote:
>
> I have looked into your patch and am a little bit worried because it
> calls RelationGetNumberOfBlocks() which is an expensive function.
> I think there are two ways to avoid it.
>
> 1) fall back to your former patch. However it may break existing
> behavior what you said. I think there's very little chance it
> actually happens because IndexBuildHeapRangeScan() is only used by
> brin (I confirmed this). But Alvaro said some patches may be it's
> customers. Robert, Amit, Can you please confirm this?
>
In earlier version of parallel_seqscan patch, heap_setscanlimits() was being
used, but now altogether a different mechanism is used.
With Regards,
Amit Kapila.
EnterpriseDB: http://www.enterprisedb.com
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