SAP Message RT644 - Average time for processing logical database requests

Diagnosis
Time used for calls to the SAP database interface.
There are various factors that influence the logical database accesstime. For example, read requests can either be processed by thedatabase buffer or by the fast local SAP buffer. The efficiency of thebuffer, the number of required accesses and the proportion of accessesthat change the dataset all influence the total access time.
The database access time is measured in the database interface on theapplication server. It therfore includes some of the application serverCPU time and the network transfer time.