Re: cache estimates, cache access cost

2011/5/19 Robert Haas <robertmhaas(at)gmail(dot)com>:
> On Tue, May 17, 2011 at 6:11 PM, Cédric Villemain
> <cedric(dot)villemain(dot)debian(at)gmail(dot)com> wrote:
>> The point is to get ratio in cache, not the distribution of the data
>> in cache (pgfincore also allows you to see this information).
>> I don't see how a stable (a server in production) system can have its
>> ratio moving up and down so fast without known pattern.
>
> Really?  It doesn't seem that hard to me.  For example, your nightly
> reports might use a different set of tables than are active during the
> day....

yes, this is known pattern, I believe we can work with it.

>
>> PS: there is very good blocker for the pg_class changes : what happens
>> in a standby ? Maybe it just opens the door on how to unlock that or
>> find another option to get the information per table but distinct per
>> server. (or we don't care, at least for a first implementation, like
>> for other parameters)
>
> That's a good point, too.
>
> --
> Robert Haas
> EnterpriseDB: http://www.enterprisedb.com
> The Enterprise PostgreSQL Company
>

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Cédric Villemain               2ndQuadrant
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