On Fri, Dec 11, 2009 at 9:00 PM, Ashish <abindra@u.washington.edu> 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 picked this because it is somewhat related to query processing which is
> what I am most interested in. It also <seems> like a good start up project
> for a newbie like me. Before I start looking into what this would involve
> and start a conversation on designing a solution - I wanted to know what you
> guys think about this particular TODO, and it suitability to a newbie.
> Looking forward to your comments...
If we're going to do this, I think we should implement this as an
optional behavior controlled by a new EXPLAIN option (maybe VARIANCE,
following Bruce's patch?) and generate the output using
ExplainProperty<some-data-type>. We could possibly make the option
take an optional threshold indicating how much variance is required
before the variance gets displayed, and display the variance for every
node if VARIANCE is specified without an argument.
...Robert