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Re: [HACKERS] Boom filters for hash joins (was: A design for amcheckheapam verification) - Mailing list pgsql-hackers

From Robert Haas
Subject Re: [HACKERS] Boom filters for hash joins (was: A design for amcheckheapam verification)
Date
Msg-id CA+TgmoYKT64JYN6E9Kfb3PRKwuP0ORY1CJDU3ibBuYBsHjcCqA@mail.gmail.com
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In response to Re: [HACKERS] Boom filters for hash joins (was: A design for amcheck heapam verification)  (Tom Lane <tgl@sss.pgh.pa.us>)
Responses Re: [HACKERS] Boom filters for hash joins (was: A design for amcheckheapam verification)
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On Mon, Sep 18, 2017 at 1:29 PM, Tom Lane <tgl@sss.pgh.pa.us> wrote:
> Uh, why does the planner need to be involved at all?

Because it loses if the Bloom filter fails to filter anything.  That's
not at all far-fetched; consider SELECT * FROM a.x, b.x WHERE a.x =
b.x given a foreign key on a.x referencing b(x).

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


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