Re: AW: Why vacuum? - Mailing list pgsql-hackers

From Daniele Orlandi
Subject Re: AW: Why vacuum?
Date
Msg-id 3A390BCB.49702539@orlandi.com
Whole thread Raw
In response to AW: Why vacuum?  (Zeugswetter Andreas SB <ZeugswetterA@wien.spardat.at>)
Responses Re: Why vacuum?  (Alfred Perlstein <bright@wintelcom.net>)
List pgsql-hackers
Zeugswetter Andreas SB wrote:
> 
> If the priority is too low you will end up with the same behavior as current,

Yes, and it is the intended behaviour. I'd use idle priority for it.

> because the cache will be emptied by high priority multiple new rows,
> thus writing to the end anyways.

Yes, but this only happens when you don't have enought spare idle CPU
time. If you are in such situation for long periods, there's nothing you
can do, you already have problems.

My approach in winning here because it allows you to have bursts of CPU
utilization without being affected by the overhead of a overwriting smgr
that (without hacks) will always try to find available slots, even in
high load situations.

> Conclusio: In those cases where overwrite would be most advantageous (high
> volume modified table) your system won't work

Why ? I have plenty of CPU time available on my server, even if one of
my table is highly volatile, fast-changing.

Bye!


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