As I understand it, HANA's SQL fully complies with the SQL 92 standard, and supports some elements of the SQL 99 standard, correct?
And more elements of later versions of the SQL standard are continually being added. For example, I was very pleased the Foreign Keys are now supported as of a December 2012 release of HANA SQL. This is a very critical addition, as FKs are required for declarative referential integrity, needed in any any sound logical data model.
The next piece of SQL 99 functionality I would like to see is common table expressions (CTEs), which don't appear to be supported in the current version of HANA. To my way of thinking, they would greatly multiply the productivity of SQL coders in HANA, help avoid procedural code (always a good idea). In my view, CTEs adhere to the relational model and are well within the spirit of HANA.
I'd be interested if other developers agree with me on the importance of CTEs in HANA. And if anyone has any idea if SAP is working towards including this feature, that would be ideal.