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Object documentation Reasons for Poor Buffer Quality  Locate the document in its SAP Library structure

Definition

Poor buffer quality may be caused by any of the following:

Transports

Every time you transport new developed source into the system that is running the tp , you invalidate all entries in the program buffer and clear all other buffers (command $SYNC ). Unlike the other buffers, the program buffer does not start empty, but is filled with invalid programs. It is very important to execute as few transports as possible and to collect data for collective transports.

Buffer resets

Setting up a buffer requires a large number of database and network accesses, and places a considerable load on the system. Therefore, only reset the buffers if inconsistencies occurred between the buffer and the database. This might happen, for example, if you update a buffered table with native SQL, that is, the database table is updated directly by bypassing the buffer. To reset the table buffers, enter $TAB in the command field. Use the command $SYNC to reset all the SAP buffers on the application server. These commands only affect the buffers of the application server on which the commands are entered. The buffers of the other application servers in the network are not affected.

Using the commands $TAB and $SYNC places an extremely large load on the system. In large systems, it could take up to one hour (depending on the access profile) for the buffer load to return to its original state. System performance is greatly impeded during this time.

Offline backups, SAP System reboots

Both of these actions require the SAP System to be shut down, and then started up again. All buffers of all servers are reset. Again, this takes a considerable amount of time.

Program development

CautionSoftware development should not be done in a productive system, as development systems require a very large program buffer.

See also:

 

High Buffer Quality