CE_JOIN Self Join Issue

Hello,

I'm trying to accomplish a self-join in HANA with the CE functions. My table, TT_UNION, looks like

...but with 50 million records. Each record is distinct, and my goal is to derive an ENDDATE. As an example, the ENDDATE for the first record should be 2013-01-31. My code has issues at the "self-join" step shown below in bold:

TT_UNION_PROJ01 = CE_PROJECTION (

          :TT_UNION,

          [GROUP, EMPLOYEE, STARTDATE AS "STARTDATE_TEMP",

               CE_CALC('IF("STARTDATE_TEMP" = DATE(''9999-12-31''), DATE(''9999-12-31''), "STARTDATE_TEMP" - 1)', DATE) AS "ENDDATE"]

          );

TT_UNION_ENDDATE01 = CE_JOIN (

          :TT_UNION,

          :TT_UNION_PROJ01,

          [GROUP, EMPLOYEE],

          [GROUP, EMPLOYEE, STARTDATE, STARTDATE_TEMP, ENDDATE]

          );

This bolded step should give a Cartesian product per GROUP and EMPLOYEE. When I count the records in TT_UNION_ENDDATE01, there are only 1.1 million records though.

Any ideas why I'm dropping records when I should get a Cartesian product?

Thanks,

Chandler