ST12 measurements keep changing for same input data (was:Performance check)
i am using Tcode ST12 for runtime analysis of a transaction. But the problem is that everytime i execute the trace, the statistics keep changing for the same input data. (especially d/b times). I guess this must be because the data gets buffered after the first time and the data is fetched from the buffer next time the transaction is run.
Is there a way to avoid this so i can get accurate statistics?
Edited by: Thomas Zloch on Jun 14, 2011 1:23 PM - subject enhanced by moderator
Yuri Ziryukin replied
No, there is no easy way to avoid it. In general we (at SAP) always analyze the second execution of the transaction to make sure that the buffers are filled. In a well-tuned system the data that are more or less often accessed are staying in the buffer.
And in case the data is displaced from the DB buffer, you have to live with the disk reads.