Re: AW: SQL row processing order for UDF

On 15-Jun-2010 11:02, Birgitta Hauser wrote:

Then you may try if an order by in a Sub-Select is allowed (DB2
UDB for isupports it since 6.1)

Select TRNADAT, Amount, MDT(TRNADAT)
From (Select TRNADAT, Amount
From MyTable
Order BY TNRADAT) x

In my experience the ORDER BY clause in a NTE was supported since at least v5r3. However also in my experience, for an NTE versus a CTE, the effect was often composite versus materialized; i.e. the query rewrite would typically eliminate the redundant NTE in the quoted example, and the ordering of the result set for the outer SELECT remains indeterminate unless explicitly specified.

"View" implementation: Views, derived tables (nested table expressions or NTEs), and common table expressions (CTEs) are implemented by the query optimizer using one of two methods....
http://publib.boulder.ibm.com/infocenter/iseries/v6r1m0/topic/rzajq/viewopt.htm
http://publib.boulder.ibm.com/infocenter/iseries/v6r1m0/topic/rzajq/viewcomposite.htm
http://publib.boulder.ibm.com/infocenter/iseries/v6r1m0/topic/rzajq/viewmaterialize.htm

And FWiW: DB2 UDB? That moniker has long been eliminated from all DB2 naming, since well over two years now.? Surely that naming has never been associated with the DB2 for i by\since the release of IBM i 6.1?

Regards, Chuck