Tuesday, 9 July 2013

What does mean by Object Swapping ( SWAP ) in SAP

Swapping occurs when the buffer is full, and the SAP System has to load additional objects into the buffer. Objects in the buffer that were used the least recently are removed. In this context, the term “swap” means the objects removed from the buffer are lost and cannot be replaced until a new database access is performed

In simple language,

the accessed data seats on the buffer, If someone is  trying to access the same data, that will be retrieved fastly from the buffer. 

If the buffer is full and some one is retrieving the data which is not there in the buffer then
that data will be placed in the buffer and the oldest data in the buffer will be swapped (Removed) for this.


More number of swaps means more DB hits. 


 SWAPS in ST02




There are two possible reasons for swapping----
There is no space left in the buffer data area
   The buffer is too small. You should increase the buffer size.

       There are no directory entries left
Although there is enough space left in the buffer, no further objects can be loaded because the number of directory entries is limited.
For the Repository buffers (nametab buffers), the number of directory entries is determined by the number of entry counts, all other buffers have there own parameter for entries.

6 comments:

  1. Very informative blog. Can you add more details about the 'no directory entries".

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