Hannu Krosing writes:
> > AFAICT, this patch does not buy us anything at all. It's just a different
> > spelling of existing functionality. We have never done that before.
>
> what about DROP COLUMN - this is also just a different spelling for
>
> SELECT INTO, migrate all constraints, DROP OLD TABLE, RENAME.
No, because DROP COLUMN preserves dependent objects.
> > We cannot possibly leave this patch as is. People expect in-place column
> > changes.
>
> Does SQL spec even require that SELECT * always returns columns in the
> same order ?
Yes:
b) Otherwise, the <select list> "*" is equivalent to a <value
expression> sequence in which each <value expression>
is a column reference that references a column of T and
each column of T is referenced exactly once. The columns
are referenced in the ascending sequence of their ordinal
position within T.
> I don't think that relational model assigns any 'order' to columns.
Correct, but SQL is not the relational model or vice versa.
> BTW, SELECT * is just a different spelling of existing functionality ;)
No, there is no other way to get a complete list of columns. (Hard-coding
does not count.)
--
Peter Eisentraut [EMAIL PROTECTED]
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TIP 9: the planner will ignore your desire to choose an index scan if your
joining column's datatypes do not match
