Only transparent tables and pooled tables can be buffered. Buffering is not permitted for cluster tables.

Character data types must be assigned to all key fields of buffered tables, that is the data type of the underlying domain must be mapped to one of the ABAP types C, N, D or T.

You should not buffer a table in the following two cases:

• The data read by the application must always be up to date. A delay caused by the synchronization mechanism is not acceptable.

• The data in the table is frequently changed. In this case the time for synchronizing could be greater than the gain in performance caused by buffering. As a rough estimate, you can assume that table buffering is not advisable if more than one percent of the table accesses are change operations.

Typical candidates for buffering include customizing and system tables. In certain cases master data with customizing character can also be buffered.

The contents of buffered tables are not always up-to-date in a distributed system. The ABAP command SELECT SINGLE... BYPASSING BUFFER allows you to bypass the buffer and read the data straight out of the database table. If a buffered table is accessed frequently with this command, you should consider whether it is really necessary for the table to be buffered or whether it is essential to have the current state of the database.