Author: Karthik C Sunil
This page will explain how to code very efficiently for nested un-related tables. The article describes how to improve the performance of processing huge data amounts.
The most common performance problem that occurs in ABAP programs is because of huge number of records in the internal tables. The problem complexifies if a program has huge nested internal tables. How much ever efficient data select routines are, data processing routines would be contributing significantly for the bad performance. When analysed it would be revealed that the where condition that is used in inner loops expend a significant amount of processing time. The idea is to avoid where conditions in the inner loops by maintaining the loop indexes manually.
Conventional Code for nested loops
Code sample: Parallel Cursor method
Nested loop for BSEG and BKPF internal tables were analysed for Conventional Method and Parallel Cursor methods. Following gragh explains the observations.
Observation: One can observe that as the data increases, the time taken for the nested loop increases drastically, at the same time, the Parallel cursor method did not suffer any considerable time impact.
Verdict: Use the parallel cursor method whenever there is a need to process data in a nested loop.