Re: Is There Any Way ....

A blast from the past is forwarded below.

douglas

Begin forwarded message:

> From: Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us>
> Date: August 23, 2005 3:23:43 PM EDT
> To: Donald Courtney <Donald(dot)Courtney(at)sun(dot)com>
> Cc: pgsql-performance(at)postgresql(dot)org, Frank Wiles <frank(at)wiles(dot)org>,
> gokulnathbabu manoharan <gokulnathbabu(at)yahoo(dot)com>
> Subject: Re: [PERFORM] Caching by Postgres
>
> Donald Courtney <Donald(dot)Courtney(at)Sun(dot)COM> writes:
>> I am not alone in having the *expectation* that a database should have
>> some cache size parameter and the option to skip the file system. If
>> I use oracle, sybase, mysql and maxdb they all have the ability to
>> size a data cache and move to 64 bits.
>
> And you're not alone in holding that opinion despite having no shred
> of evidence that it's worthwhile expanding the cache that far.
>
> However, since we've gotten tired of hearing this FUD over and over,
> 8.1 will have the ability to set shared_buffers as high as you want.
> I expect next we'll be hearing from people complaining that they
> set shared_buffers to use all of RAM and performance went into the
> tank ...
>
> regards, tom lane

On Oct 4, 2005, at 11:06 PM, Ron Peacetree wrote:

> Unfortunately, no matter what I say or do, I'm not going to please
> or convince anyone who has already have made their minds up
> to the extent that they post comments like Mr Trainor's below.
> His response style pretty much proves my earlier point that this
> is presently a religious issue within the pg community.
>
> The absolute best proof would be to build a version of pg that does
> what Oracle and DB2 have done and implement it's own DB
> specific memory manager and then compare the performance
> between the two versions on the same HW, OS, and schema.
>
> The second best proof would be to set up either DB2 or Oracle so
> that they _don't_ use their memory managers and compare their
> performance to a set up that _does_ use said memory managers
> on the same HW, OS, and schema.
>
> I don't currently have the resources for either experiment.
>
> Some might even argue that IBM (where Codd and Date worked)
> and Oracle just _might_ have had justification for the huge effort
> they put into developing such infrastructure.
>
> Then there's the large library of research on caching strategies
> in just about every HW and SW domain, including DB theory,
> that points put that the more context dependent, ie application
> or domain specific awareness, caching strategies are the better
> they are.
>
> Maybe after we do all we can about physical IO and sorting
> performance I'll take on the religious fanatics on this one.
>
> One problem set at a time.
> Ron