On Wed, Apr 22, 2020 at 2:36 PM Andres Freund <and...@anarazel.de> wrote: > > If it's any consolation, I had the same idea very recently while > > chatting with Amit Langote. Maybe it's a bad idea, but you're not the > > only one who had it. :-) > > That seems extremely hard, given our current infrastructure. I think > there's actually a good case to be made for the idea in the abstract, > but ... The amount of logic the ExecInit* routines have is substantial, > the state they set up ss complicates. A lot of nodes have state that is > private to their .c files. All executor nodes reference the > corresponding Plan nodes, so you also need to mock up those.
Right -- the idea I was talking about was to create a Plan tree without using the main planner. So it wouldn't bother costing an index scan on each index, and a sequential scan, on the target table - it would just make an index scan plan, or maybe an index path that it would then convert to an index plan. Or something like that. -- Robert Haas EnterpriseDB: http://www.enterprisedb.com The Enterprise PostgreSQL Company
