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>
Cc: 'Amit Kapila' <amit.kapila16@gmail.com>, Tom Lane <tgl@sss.pgh.pa.us>, Kyotaro Horiguchi <horikyota.ntt@gmail.com>, Andres Freund <andres@anarazel.de>, Robert Haas <robertmhaas@gmail.com>, Tomas Vondra <tomas.vondra@2ndquadrant.com>, pgsql-hackers <pgsql-hackers@postgresql.org>
Date: 2020-09-08T06:01:52Z
Lists: pgsql-hackers 
From: tsunakawa.takay@fujitsu.com <tsunakawa.takay@fujitsu.com>
> (1)
> +					INIT_BUFFERTAG(newTag,
> rnode.node, forkNum[j], firstDelBlock[j]);
> 
> And you need to use i here, too.

I remember the books "Code Complete" and/or "Readable Code" suggest to use meaningful loop variable names like fork_num and block_count, to prevent this type of mistakes.


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