SAP HR - What is Logical DataBase(LDB)?

Logical database(LDB) in SAP

The LDB is special type of ABAP program that combines the contents of certain related database tables and retrieve some related data and make it available to application programs.

·         To use logical database PNP in your program, specify in your program attributes.

LDB components

·         Standard Selection screen.

·         Data Retrieval.

·         Authorization check

Standard Selection Screen

1.    Date selection:Date selection delimits the time period for which data is evaluated. GET PERNR retrieves all records of the relevant infotypes from the database. When you enter a date selection period, the PROVIDE loop retrieves the infotype records whose validity period overlaps with at least one day of this period.

2.    Person selection:Person selection is the ‘true’ selection of choosing a group of employees for whom the report is to run.

3.    Sorting Data:(a)The standard sort sequence lists personnel numbers in ascending order.
(b)SORT function allows you to sort the report data otherwise. All the sorting fields are from infotype 0001.

4.    Report Class:(a) You can suppress input fields which are not used on the selection screen by assigning a report class to your program. (b)If SAP standard delivered report classes do not satisfy your requirements, you can create your own report class through the IMG.

Data Retrieval 

·         When you run your report, the logical database loads the personnel data for each employee into the main memory and makes it available for processing.

·         The entire history of each infotype is loaded into the main memory, that is all infotype

Authorization Check

·         The system first checks whether the user has an authorization for the employee in accordance with the criteria of organizational assignment. Employees for which the user has no authorization are not evaluated.

·         The system then checks whether the user is authorized to process the infotypes of the specified report. A list would be meaningless if the data were not evaluated completely.

Lagical Data bases in HR ABAP:

·         PNP

·         PNPCE

·         PAP

·         PCH