Re: [HACKERS] Re: [HACKERS] 答复:[HACKERS] 答复:[HACKERS] about fsync in CLOG buffer write

2015-09-09 Thread Tom Lane
Robert Haas writes: > ... How often such a workload actually has to replace a *dirty* clog > buffer obviously depends on how often you checkpoint, but if you're > getting ~28k TPS you can completely fill 32 clog buffers (1 million > transactions) in less than 40 seconds,

[HACKERS] Re: [HACKERS] 答复:[HACKERS] 答复:[HACKERS] about fsync in CLOG buffer write

2015-09-09 Thread Robert Haas
On Tue, Sep 8, 2015 at 2:28 PM, Andres Freund wrote: > On 2015-09-08 15:58:26 +0800, 周正中(德歌) wrote: >> postgres@digoal-> cat 7.sql >> select txid_current(); >> >> postgres@digoal-> pgbench -M prepared -n -r -P 1 -f ./7.sql -c 1 -j 1 -T >> 10 >> About 32K tps. >> progress:

Re: [HACKERS] Re: [HACKERS] Re: [HACKERS] 答复:[HACKERS] 答复:[HACKERS] about fsync in CLOG buffer write

2015-09-09 Thread Andres Freund
On 2015-09-09 10:46:47 -0400, Robert Haas wrote: > Well, if you're filling ~1 clog page per second, you're doing ~1 fsync > per second too. Or if you are not, then you are thrashing the > progressively smaller and smaller number of clean slots ever-harder > until no clean pages remain and you're

[HACKERS] Re: [HACKERS] Re: [HACKERS] 答复:[HACKERS] 答复:[HACKERS] about fsync in CLOG buffer write

2015-09-09 Thread Robert Haas
On Wed, Sep 9, 2015 at 10:35 AM, Tom Lane wrote: > Robert Haas writes: >> ... How often such a workload actually has to replace a *dirty* clog >> buffer obviously depends on how often you checkpoint, but if you're >> getting ~28k TPS you can completely