The SAP ABAP 3-tier architecture has 3 major layers. They are:
Presentation Layer: It is an interface or program known as “sapgui.exe” installed on a PC or Workstation of a user. This interface will accept user inputs in the form of mouse clicks, function keys, or keystrokes and will send the request that needs to be processed by the application server. The application server will send the result back to the interface and output formatting will be done in order to display it to the user.
Application Layer: This is an executable set that togetherly does ABAP/4 program interpretation and will also be able to do input/output management for them. When the application server gets started each and every executable will get started at the same time and when the application server stops, they shut down together. The details about the number of the process that began during the starting of the application server will be specified in a single configuration file known as Application Server Profile. The application server is in existence for interpreting and running the ABAP/4 programs. It is possible for an ABAP/4 program to start an executable on the presentation server but the execution of them is not possible. When an ABAP/4 program makes a request for the data from the database, then that request will be formatted by the application server, and finally, the formatted request will be sent to the database server.
Database Layer: This is an executable set that will accept requests for the database that came from the application server. The requests will be passed on to the database, it will be processed and information will be sent back to the database server, from there it will be later passed on to the application server. The application server will pass on this database retrieved information to the ABAP/4 program.
Explain the types of function modules in SAP ABAP.
Function Modules are encapsulated procedures in ABAP and are grouped in Function Groups. Function modules are created with the help of Function Builder(transaction SE37). The type of function module relies on the type of processing.
Function module types are:
Regular function module: It will be executed immediately and synchronously on the current SAP system of the user. It is the default option.
Remote-enabled function module: It is called by remote systems(R/2 or R/3) that utilize the RFC protocol. For example, it is possible to define a Remote Function Module in an EWM(Extended Warehouse Management) system which will be later called by your ERP(Enterprise Resource Planning) system for obtaining further information related to stock levels or shipment details.
The above statement calls the target system mentioned under dest synchronously. The unique name of a destination should be used for the parameter dest.
Update function module: This module will not be executed immediately. This update process will be triggered by the COMMIT WORK statement. The ROLLBACK WORK statement is responsible for deleting all update function module registrations.
IN UPDATE TASK will bundle database modifications into a single database called LUW. Since the update happens asynchronously, it is proved beneficial for performance.
BAPI(Business Application Programming Interface) function module: BAPI is a Function Module that provides a standard interface for business objects available in SAP. Common usage of BAPI is to create/delete/update/read business objects such as Business Partners, Purchase Orders, or Sales Orders.
SAP ABAP Interview Questions for Freshers
SAP(Systems, Applications, and Products in data processing) is an ERP(Enterprise Resource Planning) type of software that is used to manage the daily affairs of a large company. Advanced Business Application Programming or ABAP is the fourth-generation programming language and is used to allow the mass-processing of data in SAP business applications. It is possible to build enterprise applications for a larger business and financial institution with the help of the SAP ABAP platform. So, SAP ABAP will protect from organizational data breaches and security threats to information leakage.
SAP ABAP is suitable for integrated applications that a company will use to collect, manage, store, and interpret data from various functional areas. It will act as a single data source and share data within all the units of an organization. It helps the customers for running their business with greater accuracy.
SAP ABAP Interview Questions and Answers | ABAP | SAP Interview Questions 2022