Re: Road Map to move a home grown application from RPG to DB2 SQL or to any other data base platform

Like Vern I have always felt that the fact that we can use RLA _and_ SQL against our data is a major advantage that we should shout from the rooftops. There are occasions when RLA is the right tool for the job but the data also needs set
style access. Other systems force you to make a decision one way or the other with resulting inefficiencies - we don't have to do that.

the problem with RLA or SQL is not performance, it's design.

Using SQL it's very easy to decouple the application from the database. simply never use a table, only use views. RLA and DDS tend to navigate through the data and grab the data together (I know, this could have been done better, but most applications didn't). Following newer recommendations, using SQL DDL instead of DDS - and to use some newer features, you are forced to do so, the situation is getting worse. Views can't be accessed by RLA and indexes are limited with their definitions.. Instead triggers, for instance are a great enhancement, enabling making read only views updatable, but no way with RLA. And worse of all, as long as you have RLA access to your data, you are very restricted to refatoring of your database design.

My recommendation is: first change your access method from RLA to SQL - it's rather easy. if you introduce a functional data access layer. Then you have all prerequisites to switch your data definition from DDS to SQL DDL and redesign your database, without any harm fro your applications.

D*B