Re: How to get value of 'Param' of the WHERE clause in the FDW?

Dmitry Chichkov <dchichkov@gmail.com> writes:
> It seems like during fdwPlan(..., RelOptInfo *baserel) stage I'm getting
> baserel->baserestrictinfo, in which I see a Node *x  of  IsA(x, Param).
> But it looks like the value 'abc123' is not yet available in the planning
> stage, right?   And I don't see how can I get baserestrictinfo in the
> execution stage or if the 'abc123' value would be there...

If you are trying to get an estimated value for some subexpression at plan
time, estimate_expression_value() is what to use; see for example the uses
of that function in selfuncs.c.  Keep in mind that it *is* an estimate and
cannot be guaranteed to still be correct at execution time, since the plan
might be re-used with another parameter value.
        regards, tom lane