Horton

Re: [Patch] Optimize dropping of relation buffers using dlist

Amit Kapila <amit.kapila16@gmail.com>

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From: Amit Kapila <amit.kapila16@gmail.com>
To: "tsunakawa.takay@fujitsu.com" <tsunakawa.takay@fujitsu.com>
Cc: "k.jamison@fujitsu.com" <k.jamison@fujitsu.com>, Kyotaro Horiguchi <horikyota.ntt@gmail.com>, Tom Lane <tgl@sss.pgh.pa.us>, Andres Freund <andres@anarazel.de>, Robert Haas <robertmhaas@gmail.com>, Tomas Vondra <tomas.vondra@2ndquadrant.com>, pgsql-hackers <pgsql-hackers@postgresql.org>
Date: 2020-09-29T02:48:17Z
Lists: pgsql-hackers 
On Tue, Sep 29, 2020 at 7:21 AM tsunakawa.takay@fujitsu.com
<tsunakawa.takay@fujitsu.com> wrote:
>
> From: Jamison, Kirk/ジャミソン カーク <k.jamison@fujitsu.com>
>
> Also, as Amit-san mentioned, the cause of the slight performance regression when shared_buffers is small needs to be investigated and addressed.
>

Yes, I think it is mainly because extra instructions added in the
optimized code which doesn't make up for the loss when the size of
shared buffers is small.

-- 
With Regards,
Amit Kapila.

Commits

  1. Fix size overflow in calculation introduced by commits d6ad34f3 and bea449c6.

  2. Optimize DropRelFileNodesAllBuffers() for recovery.

  3. Optimize DropRelFileNodeBuffers() for recovery.

  4. Cache smgrnblocks() results in recovery.

  5. Add a check to prevent overwriting valid data if smgrnblocks() gives a