SAP Message AD421 - Generic buffering requires no. of key fields (please enter)

Diagnosis
You have selected the generic buffering for the table. Thismethod of buffering loads all records, which correspond with regard tothe left-hand part of the primary key, into the buffer. The size ofthis key area must be defined by specifying a number of key fields.

Procedure
Enter a key field number. To do this, select pushbutton Chnge keyfld no. and enter a number of key fields into the dialog box thatappears.