Tom Lane wrote:
Joe Conway <[EMAIL PROTECTED]> writes:
One of the things I'm struggling with is lack of column aliases. Would
it be reasonable to require something like this?
Requiring column aliases is counter to spec ...
SELECT ... FROM (VALUES ...) AS foo(col1 type1, col2 type2, ...)
... and this is even further away from it.
I figured as much, but thought I'd ask anyway :-). I did find something
in the appendix to the spec after sending this:
18) Subclause 7.3, “<table value constructor>”:
a) The column names of a <table value constructor> or a <contextually
typed table value constructor>
As for the names, just use "?column?", same as we do now in INSERT
... VALUES. Anyone who wants to refer to those columns explicitly will
need to assign aliases, but if they don't assign aliases, we don't have
to do anything very intelligent.
OK, I just thought "?column?" was ugly and useless.
As for the types, I believe that the spec pretty much dictates that we
apply the same type resolution algorithm as for a UNION. This is fairly
expensive and we should avoid it in the case of INSERT ... VALUES, but
for VALUES appearing anywhere else I think we have little choice.
Where do I find that algorithm -- somewhere in nodeAppend.c?
---------------------------(end of broadcast)---------------------------
TIP 6: explain analyze is your friend