We are exploring the use of DB2 stored procedures (or more likely, functions) in conjunction with EnterpriseOne and Cognos.
From what I've read so far, it looks like DB2 User-defined functions (UDF) are the most likely route. Unless you are on DB2 v8.1 or later, stored procedures swap processes each time you change from control statements to SQL statements, which seems to invoke a great deal of overhead.
The UDFs, on the other hand, reside in memory, but are quite different from SPs on Oracle or SQLServer. With the UDFs, you seem to have three choices - output a single variable, output a table (to be used as a datasource in a FROM clause), or output a row. Thus, the parameters are not designated as IN or OUT, since they are all IN.
DB2 does have the capability of overlaying UDFs with the same name, so long as they are different in the first 30 parameters.
The SQL I've written to convert JDE-style dates in DB2 is:
date(right(digits(SDTRDJ+1900000),7))
- where SDTRDJ is the Transaction Date - Julian from F4211. The code should result in a date-type value which could be used in all the of standard DB2 date functions.
As we make progress, I will try to post some example UDFs.