How can you Analyze the Buffer Quality?

How can you Analyze the Buffer Quality?

With transaction ST02 you can look at the statistical data on the table buffer and on individual tables. The transaction can be started by entering the transaction code or from the R/3 initial screen with the following menu options:

Tools ® Administration
Monitoring ® Performance
Setup/buffers ® Buffers

An overview of all the R/3 buffers and database calls appears.

You can look at the buffer utilization of your server during the last few days with History .

With Current parameters you can display the current valid profile parameters for the buffer sizes.

By selecting Generic key, you obtain detailed information on the generic/full table buffer. Selecting Single record gives you detailed information on the single-record table buffer. You can also access this detailed information with Goto ® Detail analysis menu and selecting Generic key or Single record in the next screen.

Selecting Buffered Objects takes you from the detailed display of the generic/full or single-record buffer to call statistics for the tables used. The displayed values help you optimize the buffer parameters in the system profile and search for unfavorably buffered tables. The statistics for the generic or full buffered tables appear if you access the call statistics from the information on generic/full buffers. If you call the statistics from the information on single-record buffers, the statistics for the single-record buffered tables are displayed.

The following information about the generic/full table buffer is displayed:

Table: Table name

Buffer state: The most important status information is valid (table entries in the buffer are valid), loading (tables are currently being loaded to the buffer), loadable (table can be loaded to the buffer with the next access) and pending (table was invalidated in the buffer and can only be loaded to the buffer after a waiting time).

Buf Key opt: Buffering type (ful = full, gen = generic, sng = single-record)

Buffer Size (Bytes): net storage area occupied by the table.

ABAP processor requests: The types of access to table records are evaluated here.

DB-Activity: Sum of the database accesses which were made to load the tables or which went directly to the database, circumventing the buffer.

Quality: Percentage of table accesses which could be satisfied from the buffer. The higher the Quality, the better is the effect of the table buffering on the performance.

You will find a more detailed description of the use of transaction ST02 in the ‘Computing Center Management System’ documentation.