BASIS LAYER Interview Questions

What are the central interfaces of the R/3 system ?
- Presentation interface
Database interface
Operating system interface

Which interface controls what is shown on the p.c. ?
- Presentation interface

Which interface converts SQL requirements in the SAP development system to those of the database ?- Database interface

What is SAP dispatcher ?
- SAP dispatcher is the control agent which manages the resources for the R/3 applications.

What are the functions of dispatcher ?
- Equal distribution of transaction load to the work processes
Management of buffer areas in main memory Integration of the presentation levels
Organization of communication activies

What is a work process ?
- A work process is where individual dialog steps are actually processed and the work is done. Each work process handles one type of request.

Name various work processes of R/3 system ?
1) Dialog or Online ( processes only one request at a time )
2) Background ( started at a specified time ) 3) Update ( primary or secondary ) 4) Enque( lock mechanism ) 5) Spool ( generated online or during back ground processing For printing )

What are the types of Update requests ?
- An update request can be divided into one primary (V1) and several Secondary update components (V2). Time-critical operations are placed in V1 component and those whose timing are less critical are placed in V2 components. If a V1 update fails, V2 components will not be processed.

What are the roll and page areas ?
- Roll and page areas are SAP R/3 buffers used to store user contexts ( process requests ) . The SAP dispatcher assigns process requests to work processes as they are received. If the work process is unavailable the process requests are queued in the roll and page areas. Paging area holds data from the application programs. Roll area holds data from previous dialog steps and data that characterizes user.

What is a Spool request ?
- Spool requests are generated during dialog or background processing and placed in the spool database with information about the printer and print format. The actual data is placed in the Tem Se (Temporary Sequential objects).

What are the different database integrities ?
- Semantic integrity
- Relational integrity
- Primary key integrity
- Value set integrity
- Foreign key integrity and
- Operational integrity.