Re: First set of OSDL Shared Mem scalability results, some

Christopher Browne wrote:

>josh@agliodbs.com (Josh Berkus) wrote:
>
>
>>This result is so surprising that I want people to take a look at it
>>and tell me if there's something wrong with the tests or some
>>bottlenecking factor that I've not seen.
>>
>>
>I'm aware of two conspicuous scenarios where ARC would be expected to
>_substantially_ improve performance:
>
> 1.  When it allows a VACUUM not to throw useful data out of
>     the shared cache in that VACUUM now only 'chews' on one
>     page of the cache;
>

Right, Josh, I assume you didn't run these test with pg_autovacuum
running, which might be interesting.

Also how do these numbers compare to 7.4?   They may not be what you
expected, but they might still be an improvment.

Matthew