Tom Lane wrote:
> Stephan Szabo <[EMAIL PROTECTED]> writes:
> > On Tue, 26 Aug 2003, Ang Chin Han wrote:
> >> Veering aside a bit, since we usually pinpoint performance problems by
> >> looking at EXPLAIN ANALYZE's differences between the planner's
> >> estimation and actual execution's stats, what's involved in parsing the
> >> EXPLAIN ANALYZE results, and highlighting the places where they are way
> >> different? Bold, underline, or put some asterisks in front of those steps.
> > The hardest part is determining where it matters I think.  You can use the
> > row counts as the base for that, but going from 1 row to 50 is not
> > necessarily going to be an issue, but it might be if a nested loop is
> > chosen.
> We've been chatting about this idea among the Red Hat group.  The RHDB
> Visual Explain tool (get it at already
> computes the percent of total runtime represented by each plan node.
> It seems like we could highlight nodes based on a large difference
> between estimated and actual percentage, or just highlight the nodes
> that are more than X percent of the runtime.

Is there a TODO here?  Perhaps:

        o Have EXPLAIN ANALYZE highlight poor optimizer estimates

  Bruce Momjian                        |
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