Horton

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

tsunakawa.takay@fujitsu.com <tsunakawa.takay@fujitsu.com>

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From: "tsunakawa.takay@fujitsu.com" <tsunakawa.takay@fujitsu.com>
To: "k.jamison@fujitsu.com" <k.jamison@fujitsu.com>, 'Amit Kapila' <amit.kapila16@gmail.com>
Cc: Kyotaro Horiguchi <horikyota.ntt@gmail.com>, "tgl@sss.pgh.pa.us" <tgl@sss.pgh.pa.us>, "andres@anarazel.de" <andres@anarazel.de>, "robertmhaas@gmail.com" <robertmhaas@gmail.com>, "tomas.vondra@2ndquadrant.com" <tomas.vondra@2ndquadrant.com>, "pgsql-hackers@postgresql.org" <pgsql-hackers@postgresql.org>
Date: 2020-10-08T02:45:06Z
Lists: pgsql-hackers 
From: Jamison, Kirk/ジャミソン カーク <k.jamison@fujitsu.com>
> With the latest patches attached, and removing the recovery check in
> smgrnblocks, I tested the performance of vacuum.
> (3 trial runs, 3.5 GB db populated with 1000 tables)
> 
> Execution Time (seconds)
> | s_b   | master | patched | %reg     |
> |-------|--------|---------|----------|
> | 128MB | 15.265 | 15.260  | -0.03%   |
> | 1GB   | 14.808 | 15.009  | 1.34%    |
> | 20GB  | 24.673 | 11.681  | -111.22% | 100GB | 74.298 | 11.724  |
> | -533.73% |
> 
> These are good results and we can see the improvements for large shared
> buffers, For small s_b, the performance is almost the same.

Very nice!

I'll try to review the patch again soon.


Regards
Takayuki Tsunakawa

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