Diagnosis
This monitoring tree element reports on the performance of the SAPsystem's most important buffers in each SAP application server.
The SAP system uses buffers to cache heavily-used and rarely-changeddata. Access to data in buffers is much faster than to data in thedatabase.
The buffers that are monitored are as follows:

• The Program Buffer (also known as the Executable Buffer, ABAP Buffer, or
PXA Buffer) buffers the compiled executable versions of ABAP programs

• The SAP Table Buffers, which are as follows:

The Single Record Buffer (TABLP or partial table buffer) buffersindividual records from SAP database tables.
The Generic Key Buffer (TABL or generic table buffer) buffers all orpart of the contents of database tables.

• The GUI Buffers, which are as follows:

The Screen Buffer (also known as the Presentation or Dynpro Buffer)buffers screens of ABAP programs (DYNPRO loads).
The CUA Buffer (also known as the Menu Buffer) buffers menu and buttondefinitions from ABAP screens.

• The SAP Repository Buffers (also known as the nametab or dictionary
buffers), which are as follows:
The Table Definition Buffer (TTAB Buffer, Table DDNTT), tabledefinitions from the SAP Repository
The Field Descriptions Buffer (FTAB Buffer, Table DDNTF), fielddescriptions from the SAP Repository
The Initial Records Buffer (IREC Buffer, contains the layout of datarecords in tables, initialized according to data type)
The Short Nametab buffer (SNTAB Buffer, combined form of the TTAB andFTAB buffers containing only the most important information from eachbuffer)

Procedure
For each SAP buffer, you will find information on the following:


• Directory used: Number of 'slots' available in percent for entries in a
buffer. If there are no free slots, then data cannot be cached in abuffer.

• Space used: The percent of the storage available in a buffer that has
been allocated for cached data.

• Hit ratio: The percentage of the time that a request for data can be
satisfied from the buffer.

• Swap: The frequency with which entries are replaced in the buffer.

Background Information