row lock promotion LWM

row lock promotion LWM (low-water mark), with the row lock promotion HWM (high-water mark) and row lock promotion PCT specifies the number of row locks permitted during a single scan session of a table or an index before SAP ASE attempts to promote from row locks to a table lock.

Summary Information

Default value

200

Range of values

2–value of row lock promotion HWM

Status

Dynamic

Display level

Intermediate

Required role

System administrator

Configuration groups

Lock Manager, SQL Server Administration

row lock promotion LWM sets the number of locks below which SAP ASE does not attempt to acquire a table lock on the object. The row lock promotion LWM must be less than or equal to row lock promotion HWM.

The default value for row lock promotion LWM is sufficient for most applications. If SAP ASE runs out of locks (except for an isolated incident), increase number of locks.

See the Performance and Tuning Series: Locking and Concurrency Control.

You can also configure lock promotion at the object level. See sp_setpglockpromote in the Reference Manual: Procedures.