Re: Optimizer improvements: to do or not to do?

From: Joshua Reich <josh(at)root(dot)net>
To: Ron Mayer <rm_pg(at)cheapcomplexdevices(dot)com>
Cc: Gregory Stark <stark(at)enterprisedb(dot)com>, pgsql-hackers(at)postgresql(dot)org
Subject: Re: Optimizer improvements: to do or not to do?
Date: 2006-09-13 22:06:37
Message-ID: 450880ED.6040509@root.net
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Ron Mayer wrote:
> Gregory Stark wrote:
>
>> Ron Mayer <rm_pg(at)cheapcomplexdevices(dot)com> writes:
>>
>>> ...vastly overestimate the number of pages .. because postgresql's guess
>>> at the correlation being practically 0 despite the fact that the distinct
>>> values for any given column are closely packed on a few pages.
>>>
>> I think we need a serious statistics jock to pipe up with some standard
>> metrics that do what we need. Otherwise we'll never have a solid footing for
>> the predictions we make and will never know how much we can trust them.
>>
>
> Do we know if any such people participate/lurk on this list, or
> if the conversation should go elsewhere?
>
I lurk... I don't know if I'm a 'statistics jock', but I may be
valuable if only I had a better understanding of how the optimizer
works. I have been following this thread with interest, but could really
do with a good pointer to background information beyond what I have read
in the main postgres manual. Does such information exist, and if so,
where ?

Josh Reich

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