SAP ABAP - Best Coding practices

Following are the some of the best practices which ABAP developer should take care to achieve optimal performance.

1.       Avoid writing select query on a same table more than once

Since the retrieval of the data from the database take most of the processing time, it is better to fetch the required data from the table and store it in a internal table for further processing

2.       Refreshing the internal tables. Clearing variables & structures

In the custom program, before using the declared internal tables, work area& variables initialize them to default values. Use CLEAR statement for variables &work area. Use REFRESH statement for internal tables

3.       Clearwork area at the end of every LOOP pass

In order to avoid the problems such as carryover of the values of some field of work area corresponding to the last loop pass to the next loop pass, we need to clear the work area at the end of every LOOP pass.

4.       Avoid using the MOVE-CORRESPONDING

Compiler has to search & map the corresponding fields in case of MOVE-CORRESPONDING statement, hence it impact the performance. So, it is better to go for individual field assignment in case of copying the work area content to other inside the LOOP.

5.       Release the memory occupied by internal tables &work area

At the end of the program uses FREE statement to release the memory occupied by the internal tables, work area& internal tables.

6.       Avoid hard coding

Declare the CONSTANTS & use them in the program instead of hard coding the values.

7.       Check SY-SUBRC value after SELECT , READ statements

Putting the appropriate set of code based on the value of the sy-subrc after SELECT or READ statement enhances the performance & helps in avoiding execution of the unwanted code

8.       Check for internal table (it_tab) IS NOT INITIAL before using FOR ALL ENTRIES

Before using FOR ALL ENTRIES in the select statements, it is best practice to check does the table in the in the FOR ALL ENTRIES is having some values, else it result in fetching 0 records.

9.       Remove the unused constants, variables, work area& internal tables from the program

Unused constants, variables, work area & internal tables are the dead codes in the program. So, by removing the dead codes we can improve the performance of the code & make the code more readable.

10.       Avoid LOOP on the same internal table more than once

Try to include the required logic inside the same LOOP in order to enhance the performance.

11.       Avoid declaring the internal tables with header line

Declare separate work area to process the records of the internal table. By doing this one can avoid the chances of not clearing the header line in case of internal table with header line.

12.       SORT the internal table before using BINARY SEARCH in the READ statement.

READ statement fails to read the entry from the table if you are using BINARY SEARCH on unsorted internal table. So, SORT the internal table by the key fields which you are using in the READ statement.

13.       Place the most probable condition in the IF statement

This enhances the performance of the code when processing large amount of data.