alt Hacker NewsA bitmap index scan allows the database to narrow down which pages could include the data, but then still has to recheck the condition on the contents of those pages - so will still not be as performant as an proper index scan
A bitmap index scan allows the database to narrow down which pages could include the data, but then still has to recheck the condition on the contents of those pages - so will still not be as performant as an proper index scan
With postgres indexes not containing liveness data for tuples you'll have to hit quite a lot of those pages anyway, unless they are frozen.