Time Waited On Locks

Snapshot Information Level
Database
Application

API Structure(s)
sqlm_dbase
sqlm_appl
sqlm_appl_lock

Monitor Group
Lock
Lock

Resettable

Yes

Event Information Level
Database
Connection
Transaction

API Structure(s)
sqlm_db_event
sqlm_conn_event
sqlm_xaction_event

API Element Name
Element Type

lock_wait_time
counter

Description:  The total elapsed time waited for a lock.

Usage:  At the database level, this is the total amount of elapsed time that all applications were waiting for a lock within this database.

At the application-connection and transaction levels, this is the total amount of elapsed time that this connection or transaction has waited for a lock to be granted to it.

This element may be used in conjunction with the "Lock Waits" monitor element to calculate the average wait time for a lock. This calculation can be performed at either the database or the application-connection level.

When using data elements providing elapsed times, you should consider:

• Elapsed times are affected by system load, so the more processes you have running, the higher this elapsed time value.

• To calculate this data element at the database level, the database system monitor sums the application-level times. This can result in double counting elapsed times at a database level, since more than one application process can be running at the same time.

  To provide meaningful data, you can calculate the average wait time for a lock, as described above.

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