Re: Load Distributed Checkpoints test results - Mailing list pgsql-hackers

From Gregory Maxwell
Subject Re: Load Distributed Checkpoints test results
Date
Msg-id e692861c0706151328g1b7a097j4817042760e9dcc0@mail.gmail.com
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In response to Re: Load Distributed Checkpoints test results  (Gregory Stark <stark@enterprisedb.com>)
Responses Re: Load Distributed Checkpoints test results
Re: Load Distributed Checkpoints test results
List pgsql-hackers
On 6/15/07, Gregory Stark <stark@enterprisedb.com> wrote:
> While in theory spreading out the writes could have a detrimental effect I
> think we should wait until we see actual numbers. I have a pretty strong
> suspicion that the effect would be pretty minimal. We're still doing the same
> amount of i/o total, just with a slightly less chance for the elevator
> algorithm to optimize the pattern.

..and the sort patching suggests that the OS's elevator isn't doing a
great job for large flushes in any case. I wouldn't be shocked to see
load distributed checkpoints cause an unconditional improvement since
they may do better at avoiding the huge burst behavior that is
overrunning the OS elevator in any case.


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