Date: Wed, 13 May 2020 16:57:39 +0200
From: Tomas Vondra <tomas.vondra@2ndquadrant.com>
To: Tom Lane <tgl@sss.pgh.pa.us>
Cc: Fujii Masao <masao.fujii@oss.nttdata.com>,
	Alvaro Herrera <alvherre@2ndquadrant.com>,
	Masahiko Sawada <masahiko.sawada@2ndquadrant.com>,
	"tsunakawa.takay@fujitsu.com" <tsunakawa.takay@fujitsu.com>,
	"pgsql-hackers@postgresql.org" <pgsql-hackers@postgresql.org>
Subject: Re: SLRU statistics
Message-ID: <20200513145739.wlnbse5rw3vvscyr@development>
References: <0e1c8904-13be-ab70-0096-54f0b30e43ba@oss.nttdata.com>
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 <49b8ad17-f6d9-a086-a952-ff1fec3ac1b3@oss.nttdata.com>
 <20200502105500.hwhba3d6s3hlrqf6@development>
 <20200502165905.brfxv6dk5vjdbgti@development>
 <976bbb73-a112-de3c-c488-b34b64609793@oss.nttdata.com>
 <b8784fe6-1401-ab35-aa14-d57b5bb8e312@oss.nttdata.com>
 <20200513082159.myflgcs5fnhnujbk@development>
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On Wed, May 13, 2020 at 10:26:39AM -0400, Tom Lane wrote:
>Fujii Masao <masao.fujii@oss.nttdata.com> writes:
>> On 2020/05/13 17:21, Tomas Vondra wrote:
>>> On Wed, May 13, 2020 at 04:10:30PM +0900, Fujii Masao wrote:
>>>> Also I found another minor issue; SLRUStats has not been initialized to 0
>>>> and which could update the counters unexpectedly. Attached patch fixes
>>>> this issue.
>
>> Pushed both. Thanks!
>
>Why is that necessary?  A static variable is defined by C to start off
>as zeroes.
>

But is it a static variable? It's not declared as 'static' but maybe we
can assume it inits to zeroes anyway? I see we do that for
BgWriterStats.


regards

-- 
Tomas Vondra                  http://www.2ndQuadrant.com
PostgreSQL Development, 24x7 Support, Remote DBA, Training & Services