Re: Question about Bitmap Heap Scan/BitmapAnd

"Guillaume Smet" <guillaume(dot)smet(at)gmail(dot)com> writes:
> What surprises me is that "parking" is in the filter and not in the
> Recheck Cond whereas it's part of the second Bitmap Index Scan of the
> Bitmap And node.

That's probably because of this:

/*
* When dealing with special or lossy operators, we will at this point
* have duplicate clauses in qpqual and bitmapqualorig. We may as well
* drop 'em from bitmapqualorig, since there's no point in making the
* tests twice.
*/
bitmapqualorig = list_difference_ptr(bitmapqualorig, qpqual);

What's not immediately clear is why the condition was in both lists to
start with. Perhaps idx_lieu_parking is a partial index with this as
its WHERE condition?

regards, tom lane