Data Writer 

Data writers are user kernel threads (UKT). Data writer tasks are responsible for writing data from the data cache to the data devspaces. They become active when a savepoint or checkpoint is performed.

Savepoint writing takes a long time for a large data cache. The data writers also become active between the end of one and the start of the next savepoint, to write data asynchronously from the data cache to disk.

The number of data writers is calculated by the system. It depends primarily on the data cache size and the number of data devspaces.