Re: Protect syscache from bloating with negative cache entries - Mailing list pgsql-hackers

From Kenneth Marshall
Subject Re: Protect syscache from bloating with negative cache entries
Date
Msg-id 20190115184419.GF22649@aart.rice.edu
Whole thread Raw
In response to Re: Protect syscache from bloating with negative cache entries  (Tom Lane <tgl@sss.pgh.pa.us>)
List pgsql-hackers
On Tue, Jan 15, 2019 at 01:32:36PM -0500, Tom Lane wrote:
> ... 
> > FYI, Oracle provides one parameter, shared_pool_size, that determine the
> > size of a memory area that contains SQL plans and various dictionary
> > objects.  Oracle decides how to divide the area among constituents.  So
> > it could be possible that one component (e.g. table/index metadata) is
> > short of space, and another (e.g. SQL plans) has free space.  Oracle
> > provides a system view to see the free space and hit/miss of each
> > component.  If one component suffers from memory shortage, the user
> > increases shared_pool_size.  This is similar to what Horiguchi-san is
> > proposing.
> 
> Oracle seldom impresses me as having designs we ought to follow.
> They have a well-earned reputation for requiring a lot of expertise to
> operate, which is not the direction this project should be going in.
> In particular, I don't want to "solve" cache size issues by exposing
> a bunch of knobs that most users won't know how to twiddle.
> 
>             regards, tom lane

+1

Regards,
Ken 


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