Re: stats_block_level

On Jul 27, 2007, at 6:45 PM, Jim Nasby wrote:

> On Jul 26, 2007, at 2:03 PM, Tom Lane wrote:
>> So maybe the *real* question to ask is why we have separate GUCs for
>> stats_row_level and stats_block_level.  Shouldn't we fold them into a
>> single switch?  It's hard to see what having just one of them
>> turned on
>> will save.
>
> IIRC, the guys at Emma have seen a performance difference with
> stats_block_level off and row_level on, presumable due in part to
> having 150k tables.
>
> Erik? Kim?

Well, we turned it off at the same time we moved from 8.2.3 to 8.2.4
so the actual culprit may have been what prompted the stats collector
improvement that went into that release.  I could test turning it
back on this week if you like -- I certainly would like to have my
blks_read/cach_hits stats back.  Toggling stats_block_level will
respond to a reload, yes?

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