Re: index paths and enable_indexscan

Amit Langote  writes:
> I was really thinking of this in terms of planner effort, which for
> creating an index path is more than creating sequential path, although
> sure the payoff can be great. That is, I want the planner to avoid
> creating index paths *to save cycles*, but see no way of making that
> happen.  I was thinking disabling enable_indexscan would do the trick.

I think that's completely misguided, because in point of fact nobody
is going to care about the planner's performance with enable_indexscan
turned off.  It's not an interesting production case.

All of these enable_xxx switches exist just for debug purposes, and so
the right way to think about them is "what's the simplest, least
bug-prone, lowest-maintenance way to get the effect?".

Likewise, I don't actually much care what results you get if you turn
off *all* of them.  It's not a useful case to spend our effort on.

			regards, tom lane