deadlock checking period

deadlock checking period specifies the minimum amount of time (in milliseconds) before SAP ASE initiates a deadlock check for a process that is waiting on a lock to be released.

Summary Information
Default value	500
Range of values	0–2147483
Status	Dynamic
Display level	Comprehensive
Required role	System administrator
Configuration group	Lock Manager

Deadlock checking is time-consuming overhead for applications that experience no or very few deadlocks, and the overhead grows as the percentage of lock requests that must wait for a lock also increases.

If you set deadlock checking period to a nonzero value (n), SAP ASE initiates a deadlock check after a process waits at least n milliseconds. For example, you can make a process wait at least 700 milliseconds for a lock before each deadlock check by entering:

sp_configure "deadlock checking period", 700

If you set deadlock checking period to 0, SAP ASE initiates deadlock checking when each process begins to wait for a lock. Any value less than the number of milliseconds in a clock tick is treated as 0.

Configuring deadlock checking period to a higher value produces longer delays before deadlocks are detected. However, since SAP ASE grants most lock requests before this time elapses, the deadlock checking overhead is avoided for those lock requests. If your applications deadlock infrequently, set deadlock checking period to a higher value. Otherwise, the default value of 500 should suffice.

Use sp_sysmon to determine the frequency of deadlocks in your system and the best setting for deadlock checking period. See the Performance and Tuning Series: Monitoring SAP ASE with sp_sysmon.