DB2 for z/OS: Data Sharing in a Nutshell

56 Data Sharing in a Nutshell

Roughly speaking, a duplexed lock can easily take 3 times the cost of a

simplexed DB2 lock request. For example, if a synchronous lock takes 10 µsec,

then a duplexed lock, when performed synchronously, would take about 30 µsec.

It is likely that the lock would be converted to asynchronous in order to spare the

host processor, which must spin while asynchronous activity is performed. The

asynchronous lock is likely to take more than 100 µsec at the least.

For more information, refer to System-Managed Coupling Facility Structure

Duplexing

, GM13-0103, at:

http://www.ibm.com/servers/eserver/zseries/library/techpapers/gm130103.html

You can find another related white paper, System-Managed CF Structure

Duplexing Implementation ...