Horton

RE: [PATCH] Speedup truncates of relation forks

Jamison, Kirk <k.jamison@jp.fujitsu.com>

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From: "Jamison, Kirk" <k.jamison@jp.fujitsu.com>
To: 'Masahiko Sawada' <sawada.mshk@gmail.com>
Cc: "Tsunakawa, Takayuki" <tsunakawa.takay@jp.fujitsu.com>, Tomas Vondra <tomas.vondra@2ndquadrant.com>, "pgsql-hackers@postgresql.org" <pgsql-hackers@postgresql.org>
Date: 2019-06-17T08:01:04Z
Lists: pgsql-hackers

Commits

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  1. Speedup truncations of relation forks.

  2. Remove unused smgrdounlinkfork() function.

  3. Accelerate end-of-transaction dropping of relations

Attachments

Hi all,

Attached is the v2 of the patch. I added the optimization that Sawada-san
suggested for DropRelFileNodeBuffers, although I did not acquire the lock
when comparing the minBlock and target block. 

There's actually a comment written in the source code that we could
pre-check buffer tag for forkNum and blockNum, but given that FSM and VM
blocks are small compared to main fork's, the additional benefit of doing so 
would be small.

>* We could check forkNum and blockNum as well as the rnode, but the
>* incremental win from doing so seems small.

I personally think it's alright not to include the suggested pre-checking.
If that's the case, we can just follow the patch v1 version.

Thoughts?

Comments and reviews from other parts of the patch are also very much welcome.

Regards,
Kirk Jamison