Re: 9.2rc1 produces incorrect results

I wrote:
> I think probably the best fix is to rejigger things so that Params
> assigned by different executions of SS_replace_correlation_vars and
> createplan.c can't share PARAM_EXEC numbers.  This will result in
> rather larger ecxt_param_exec_vals arrays at runtime, but the array
> entries aren't very large, so I don't think it'll matter.

Attached is a draft patch against HEAD for this.  I think it makes the
planner's handling of outer-level Params far less squishy than it's ever
been, but it is rather a large change.  Not sure whether to risk pushing
it into 9.2 right now, or wait till after we cut 9.2.0 ... thoughts?

			regards, tom lane