RE: [PATCH] Speedup truncates of relation forks

From: "Jamison, Kirk" <k(dot)jamison(at)jp(dot)fujitsu(dot)com>
To: 'Masahiko Sawada' <sawada(dot)mshk(at)gmail(dot)com>
Cc: "Tsunakawa, Takayuki" <tsunakawa(dot)takay(at)jp(dot)fujitsu(dot)com>, Tomas Vondra <tomas(dot)vondra(at)2ndquadrant(dot)com>, "pgsql-hackers(at)postgresql(dot)org" <pgsql-hackers(at)postgresql(dot)org>
Subject: RE: [PATCH] Speedup truncates of relation forks
Date: 2019-06-17 08:01:04
Message-ID: D09B13F772D2274BB348A310EE3027C64E3E2F@g01jpexmbkw24
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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.


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

Kirk Jamison

Attachment Content-Type Size
v2-0001-Speedup-truncates-of-relation-forks.patch application/octet-stream 22.6 KB

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