2011/9/19 Vitalii Tymchyshyn <tivv00@gmail.com>:
> 17.09.11 23:01, Stefan Keller написав(ла):
>>
>> * more... ?
>
> What I miss from my DB2 UDB days are buffer pools. In PostgreSQL terms this
> would be part of shared buffers dedicated to a relation or a set of
> relations. When you have a big DB (not fitting in memory) you also usually
> want some small tables/indexes be in memory, no matter what other load DB
> has.
> Complimentary features are:
> 1) Relations preloading at startup - ensure this relation are in memory.
you can use pgfincore extension to achieve that, for the OS cache. It
does not look interesting to do that for shared_buffers of postgresql
(the subject has been discussed and can be discussed again, please
check mailling list archieve first)
> 2) Per buffer pool (or relation) page costs - tell it that this
> indexes/tables ARE in memory
you can use tablespace parameters (*_cost) for that, it has been
rejected for tables in the past.
I did propose something to start to work in this direction.
See "[WIP] cache estimates, cache access cost" in postgresql-hackers
mailling list.
This proposal let inform the planner of the table memory usage and
take that into account.
>
> Best regards, Vitalii Tymchyshyn.
>
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