Re: RFD: Discarded tuple count for SeqScan nodes in EXPLAIN ANALYZE

Andres Freund <andres@anarazel.de> writes:
> On 05/22/2009 03:42 PM, Heikki Linnakangas wrote:
>> Isn't the discarded count always equal to (# of rows in table - matched
>> tuples)? Seems pretty redundant to me.

> Not for EXISTS(), LIMIT and similar.

It doesn't really seem useful enough to justify breaking client-side
code that looks at EXPLAIN output.

This sort of ties into the discussions we have periodically about
allowing EXPLAIN to output XML or some other more-machine-friendly
data format.  The barrier for adding additional output fields would
be a lot lower in such a format.
        regards, tom lane