I ran a SQL statement on a system which database is DB6. The SQL statement is as below.
SELECT * FROM MABW WHERE MANDT = '800' AND WERKS LIKE 'R100000%' AND MATNR = 'R300' AND LGORT = '0002'.
The index MABW~W includes fields 'MANDT', 'WERKS', 'MATNR' and 'LGORT'.
I pressed 'Explain' button. And the access plan was shown as below. I don't know why the key columns is 4. I think the key columns should be 2. Because the second field 'WERKS' I used 'LIKE 'cond%' '. Who can tell me why it is 4? Thank you very much.