Re: 9.3 Pre-proposal: Range Merge Join

On Apr 16, 2012, at 1:40 AM, Jeff Davis <pgsql(at)j-davis(dot)com> wrote:
> See attached SQL for example. The
> Problem statement: slow. Nested loops are the only option, although they
> can benefit from an inner GiST index if available. But if the join is
> happening up in the plan tree somewhere, then it's impossible for any
> index to be available.

Hmm. This sounds like something that Tom's recent work on parameterized plans ought to have fixed, or if not, it seems closely related. And by "this" I mean specifically the ability to use a GiST index to drive a nested loop that is higher up in the plan tree than the immediate parent of the index scan.

This is not an argument against your proposal, just an observation.

...Robert