When using channel devices to communicate with the database, system performance is affected by the load on the block multiplexer channel connected to the database.
For the best system performance, a channel that is used by the database should be dedicated to devices to that Database. However, if research at your site indicates that a channel is not overloaded, the block multiplexer channel can be shared with other devices, such as disk or tape devices.
It is the responsibility of a site to monitor channel utilization to determine if it is high enough to degrade the performance on the database. Note that an overloaded channel results in I/O delays for other devices on that channel.