"Nick Fankhauser" <nickf@ontko.com> writes:
> The part that looks wrong to me is that on the last line of the explain, it
> is using the index "actor_case_assignment_both" (the index on
> actor_id,case_id) even though actor_id is never referenced in this query and
> and index on case_id alone is available.
That seems strange to me also, particularly if the index column ordering
is indeed actor_id,case_id and not the other way round --- without some
constraint on actor_id it shouldn't be *possible* to use such an index.
Could you send me a schema dump (pg_dump -s) for experimentation?
Also, which PG version are you using?
regards, tom lane