Developing Persistence 

With its three-layer architecture, the SAP NW AS is connected to a single, system-integrated database. Not only are all programs stored here, but this is also the location where various types of data are made persistent. The most important types of database storage with the SAP NW AS are:

·        With database-independent Open SQL, which is integrated in ABAP, you store your data from the program in database tables and write the data in the program to internal tables, which are high-performing and enable fast search access. This method should be your first choice.

·        With Object Services, selected objects are made persistent transparently, after you have defined an assignment between attributes and table columns. You should choose this method if you wish to use object-oriented programming throughout.

·        With the EXEC SQL command, you can use the proprietary SQL of the integrated database, as well as open additional connections to other SAP-supported databases and access them with their SQL.

You create database tables in the ABAP Dictionary with metadata support. When you activate the objects, the database tables are created on the database. The data types are then available system-wide. For transactions, lock management, and authorization checks, the SAP NW Application Server has separate solutions, since the relevant services of the database do not meet flexibility requirements.

 

Detailed information is available under External Data Storage.