Re: 7.0.3(nofsync) vs 7.1

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> I've run tests (with 50 .. 250 simult users) for some PG project
> of my company. 7.1 was 3 times faster than 7.0.3 (fsync) but near
> 3 times slower than 7.0.3 (nofsync). It was not the best day in
> my life - WAL looked like big bottleneck -:(
>
> But finally I've realized that this test makes ~3 FK insertions
> ... and FK insert means SELECT FOR UPDATE ... and this could
> reduce # of commits per fsync.
>
> So, I've run simple test (below) to check this. Seems that 7.1
> is faster than 7.0.3 (nofsync), and that SELECT FOR UPDATE in RI
> triggers is quite bad for performance.
>
> Please take this into account when comparing 7.1 with 7.0.3.
> Also, we should add new TODO item: implement dirty reads
> and use them in RI triggers.

Added:

* Implement dirty reads and use them in RI triggers

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Bruce Momjian | http://candle.pha.pa.us
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