Re: Improving count(*) - Mailing list pgsql-hackers

From Steve Wampler
Subject Re: Improving count(*)
Date
Msg-id 437DCF4A.9030802@noao.edu
Whole thread Raw
In response to Re: Improving count(*)  (Tom Lane <tgl@sss.pgh.pa.us>)
List pgsql-hackers
Tom Lane wrote:
> Simon Riggs <simon@2ndquadrant.com> writes:
> 
>>From here, another proposal. We have a GUC called count_uses_estimate
>>that is set to off by default. If set to true, then a count(*) will use
>>the planner logic to estimate number of rows in the table and return
>>that as the answer, rather than actually count the row.
> 
> 
> Ugh.  Why not just provide a function to retrieve the planner estimate,
> but *not* call it count(*)?  It would fit nicely with the contrib/dbsize
> stuff (or I should say, the stuff formerly in dbsize...)

That would completely remove my needs for a fast count() - all I want
is a way to quickly estimate table sizes for an operator's display.  Tom's
suggestion would provide exactly that.

-- 
Steve Wampler -- swampler@noao.edu
The gods that smiled on your birth are now laughing out loud.


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