On Wed, Aug 19, 2026 at 07:31:18PM +0200, Tomas Vondra wrote: > On 8/19/26 17:05, Bruce Momjian wrote: > > One topic that came up in the Pittsburgh AI Workshop was the idea of > > combining indexes. For example, right now, all indexes point to heap, > > and we usually go from index to heap. We can combine indexes using > > bitmap scans of heap tids. Would there be any value of improving our > > ability to combine indexes beyond bitmap scans? > > > > Are you describing something like this [1]? That is, ability to build a > bitmap (from bitmap index scan), and pass it into an index scan, so that > it can benefit from the selective bitmap filter and ordering of the > regular index scan? > > I think that's an interesting idea / scan variant, skipping a possibly > expensive Sort. But I don't quite see how is that related to the topic > of this thread? It transfers predicate within a single scan (from one > index to the other), while the hashjoin bloom pushdown "transfers" > predicates between different plan nodes, possibly very distant.
Yeah, not sure what I am asking. It was just a thought that maybe more flexible index combining can be helpful. -- Bruce Momjian <[email protected]> https://momjian.us EDB https://enterprisedb.com Do not let urgent matters crowd out time for investment in the future.
