Dev Thread 

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 depends primarily on the number of devspaces in the database instance. Under normal circumstances, two dev processes/threads are activated for the system devspace and for each data devspace and log devspace Only 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.

All the other dev threads write data to or read it from the devspaces.