User task physical writes: <count>
Modified pages are swapped from the data cache to the data area, since not all of the data used by the applications can be held in the data cache.
If the data cache were large enough, the physical write would be delayed to the next savepoint, and be performed asynchronously. Cache displacements, however, cause synchronous writes and reads, and must be avoided.
This phenomenon is almost unavoidable if load times (data import) are long, since the imported data is usually much larger than the size of the data cache.
Increase the size of the data cache.