How do you take care of performance issues in your ABAP programs?

Performance of ABAPs can be improved by minimizing the amount of data to be transferred.

The data set must be transferred through the network to the applications, so reducing the amount OF time and also reduces the network traffic.

Some measures that can be taken are:
- Use views defined in the ABAP/4 DDIC (also has the advantage of better reusability).
- Use field list (SELECT clause) rather than SELECT *.
- Range tables should be avoided (IN operator)
- Avoid nested SELECTS.

i)system tools
ii)field symbols and field groups.

Field Symbols : Field symbols are placeholders for existing fields. A Field Symbol does not physically reserve space for a field, but points to a field which is not known until runtime of the program.
eg:- FIELD-SYMBOL <FS> [<TYPE>].

Field groups: A field group combines several fields under one name. At runtime, the INSERT command is used to define which data fields are assigned to which field group.

There should always be a HEADER field group that defines how the extracted data will be sorted; the data is sorted by the fields grouped under the HEADER field group.