Hi,

Obj- operations generate their own SQL while RDB- operations rely on the query written in Rule-Connect-SQL instances. Unless there is a need for custom SQL which cannot be solved by Obj- operations, RDB- operations are best avoided. That said, in situations where you need to insert using a select statement or delete multiple records based on a filter criteria, equivalent Obj- operations are currently not available and thus RDB- operations are useful.

Generally all queries should be through the use of Obj methods. If you use RDB methods, you will not be able to access BLOBs. However, RDB methods are necessary if you want to execute stored procedures.

RDB methods would be considered in the below factors

1) stored procedure

2) custom or complex query

3) SQL function

In addition :

1. Obj methods can only be queried upon a single class whereas RDB methods can be helpful in querying along with joins involving more than one class.

2. Obj methods are meant for transactional ease as they have the option of deferred save, rollback etc whereas RDB methods are performed immediately with auto-commit.

Hope this helps.