Horton

Re: Need a mentor, and a project.

Decibel! <decibel@decibel.org>

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From: decibel <decibel@decibel.org>
To: Tom Lane <tgl@sss.pgh.pa.us>
Cc: Bruce Momjian <bruce@momjian.us>, Ashish <abindra@u.washington.edu>, Josh Berkus <josh@agliodbs.com>, Joshua Tolley <eggyknap@gmail.com>, Albe Laurenz <laurenz.albe@wien.gv.at>, pgsql-hackers@postgresql.org
Date: 2009-12-15T20:31:19Z
Lists: pgsql-hackers 
On Dec 11, 2009, at 8:44 PM, Tom Lane wrote:
> Bruce Momjian <bruce@momjian.us> writes:
>> Ashish wrote:
>>> I am thinking about starting with the following TODO item:
>>> --> Have EXPLAIN ANALYZE issue NOTICE messages when the estimated
>>> and actual row counts differ by a specified percentage.
> 
>> I even have a sample patch you can use as a start, attached.
> 
> IMO the hard part of the TODO item is to design a useful user interface
> for highlighting specific EXPLAIN entries (and NOTICE messages probably
> ain't it either).  Getting the numbers is trivial.

What about prefixing explain output with line numbers? NOTICEs (or whatever mechanism) could then reference the line numbers.

Unfortunately, I think you'll be very hard-pressed to come up with a way to denote problems on the lines themselves, since horizontal space is already very hard to come by in complex plans.
--
Jim C. Nasby, Database Architect                   jim@nasby.net
512.569.9461 (cell)                         http://jim.nasby.net