Which Tables Should be Buffered?

Which Tables Should be Buffered?

Only transparent tables and pooled tables can be buffered. Cluster tables cannot be buffered.

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.

The following two points speak against table buffering:

The data read by the application must always be up-to-date. Delays caused by the synchronization mechanism (see Synchronization of Local Buffers) cannot be accepted.

The table data is frequently modified. In this case the cost of synchronization could be greater than the gain in performance resulting from buffering. Roughly speaking, it does not make sense to buffer a table if more than one percent of the accesses to the table are modifying accesses.

The table containing currency exchange rates is updated only once a day, but it is read frequently. Buffering is recommended in this case.

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 can be used to bypass the buffer, thereby reading the data directly from 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 and whether it is essential to have the current database contents.

You must define whether and how a table is buffered in its technical settings (see Technical Settings).