Horton

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

Thomas Munro <thomas.munro@gmail.com>

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From: Thomas Munro <thomas.munro@gmail.com>
To: "k.jamison@fujitsu.com" <k.jamison@fujitsu.com>
Cc: Amit Kapila <amit.kapila16@gmail.com>, Kyotaro Horiguchi <horikyota.ntt@gmail.com>, "tanghy.fnst@cn.fujitsu.com" <tanghy.fnst@cn.fujitsu.com>, "tsunakawa.takay@fujitsu.com" <tsunakawa.takay@fujitsu.com>, Andres Freund <andres@anarazel.de>, Tom Lane <tgl@sss.pgh.pa.us>, Robert Haas <robertmhaas@gmail.com>, Tomas Vondra <tomas.vondra@2ndquadrant.com>, pgsql-hackers <pgsql-hackers@postgresql.org>, "jankirk.jamison@gmail.com" <jankirk.jamison@gmail.com>
Date: 2021-03-11T23:27:45Z
Lists: pgsql-hackers 
While rebasing CF #2933 (which drops the _cached stuff and makes this
optimisation always available, woo), I happened to notice that we're
summing the size of many relations and forks into a variable
nBlocksToInvalidate of type BlockNumber.  That could overflow.

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