Improve output of BitmapAnd EXPLAIN ANALYZE

A customer just pinged me wondering how it was that a BitmapAnd node was 
reporting 0 tuples when the Bitmap Heap Scan above it showed it had in 
fact generated tuples.

While this is mentioned in the docs, I think it would be very helpful to 
have ANALYZE spit out "N/A" instead of 0 for these nodes. AFAICT that 
would just require adding a special case to the "if (es->costs)" block 
at line ~1204 in explain.c?

BTW, it looks like it would actually be possible to return a real 
row-count if none of the TIDBitmap pages are chunks, but I'm not sure if 
it's worth the extra effort.
-- 
Jim Nasby, Data Architect, Blue Treble Consulting, Austin TX
Experts in Analytics, Data Architecture and PostgreSQL
Data in Trouble? Get it in Treble! http://BlueTreble.com
855-TREBLE2 (855-873-2532)   mobile: 512-569-9461