Re: Database Caching - Mailing list pgsql-hackers

From Tom Lane
Subject Re: Database Caching
Date
Msg-id 16039.1014938846@sss.pgh.pa.us
Whole thread Raw
In response to Database Caching  ("Greg Sabino Mullane" <greg@turnstep.com>)
Responses Re: Database Caching  (Jan Wieck <janwieck@yahoo.com>)
List pgsql-hackers
"Greg Sabino Mullane" <greg@turnstep.com> writes:
> III. Relation caching

> The final cache is the relation itself, and simply involves putting the entire 
> relation into memory. This cache has a field for the name of the relation, 
> the table info itself, the type (indexes should ideally be cached more than 
> tables, for example), the access time, and the acccess number. Loading could 
> be done automatically, but most likely should be done according to a flag 
> on the table itself or as an explicit command by the user.

This would be a complete waste of time; the buffer cache (both Postgres'
own, and the kernel's disk cache) serves the purpose already.

As I've commented before, I have deep misgivings about the idea of a
query-result cache, too.
        regards, tom lane


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