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.
Of course, the reason that patch isn't already in there is that it's
pretty much useless. It clutters what's already cluttered output
and doesn't do much of anything to help draw one's attention to the
larger estimation errors, which of course is what the TODO item is
really about.
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.
I'm not sure there is any really nice solution within the confines of
plain ASCII text output. There was an interesting approach online
at http://explain-analyze.info, but that site seems to be down now :-(
regards, tom lane