I wrote:
> I'm thinking that IN should be
> converted to a ScalarArrayOpExpr, ie
> x = ANY (ARRAY[val1,val2,val3,val4,...])
Actually, there is one little thing in the way of doing this: it'll
fail if any of the IN-list elements are NULL, because we have not got
support for arrays with null elements. So we'd have to fix that first.
regards, tom lane