Re: Referencing a superselect's column by it's declared alias from a subselect fails

Casey Allen Shobe <cshobe@secureworks.net> writes:
> In the following statement (which works), if I s/ps."usesysid"/"UID"/ in the
> two innermost subselects (such that it refers to the declared alias rather
> than the true column name), it fails.  In DB2, it works in similar
> situations.

I find that hard to believe.  If true, DB2 is broken.  An output-column
alias should not be visible in expressions for other output columns.
There are obvious circularity problems with allowing such a thing.

            regards, tom lane