SQLRPG isn’t that new, it’s been around for some time now. It basically allows you to use SQL statements in your RPG program for database operations (embedded SQL). You can embed SQL in ILE RPG or OPM RPG.
The main advantage is that it allows some very complex data selections, which would otherwise involve a lot of RPG coding and database I/O.
The main disadvantage is that it can use a lot of machine resource and adversely affect the performance of your machine. This is very much dependent on how you use it and your database design.