It’s very easy to get tied up in knots where performance is concerned when you’re working with internal tables – especially when they’re getting really big. In fact these problems often only arise after a few months, when the tables tend to grow as time goes by. For example, when you’re looping two tables, one of headers and another of entries, do you do this? LOOP AT itab1 ASSIGNING <fs1>. LOOP AT itab2 ASSGNING <fs2> WHERE field1 = <fs1>-field1.