Greg Stark <gsstark(at)mit(dot)edu> writes:
> Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us> writes:
>> ORing and ANDing of such bitmaps still works, with the understanding
>> that it's lossy and you have to double check each retrieved tuple.
> That would make it really hard to ever clear the bits.
We're speaking of in-memory bitmaps constructed on-the-fly here. You're
right that it wouldn't work for persistent indexes, but I'm not very
interested in that case at the moment ...
regards, tom lane