Object documentation Dev Thread Locate the document in its SAP Library structure

Dev threads are special threads. Dev threads handle the read and write commands that read and write tasks ask to have performed.

The number of dev threads is primarily dependent on the number of volumes in the database instance. Under normal circumstances, two dev threads are activated for every data volume and every log volume. One dev thread is activated for writing the kernel trace, if it is enabled.

The dev thread dev0 plays a special role; dev0 coordinates and monitors the dev threads.

·        For example, if a log volume fails while the database is running (bad volume), dev0 ensures that the corresponding dev threads are terminated. The database instance is transferred to OFFLINE mode.

·        If the database is enlarged while running by adding another data volume, dev0 ensures that new dev threads are generated.

All the other dev<i> threads write data to or read data from the volumes.