Summary information |
|
|---|---|
Default value |
200 |
Range of values |
2–value of page lock promotion HWM |
Status |
Dynamic |
Display level |
Intermediate |
Required role |
System Administrator |
The page lock promotion LWM low-water mark) parameter, together with the page lock promotion HWM (high-water mark) and the page lock promotion PCT, specify the number of page locks permitted during a single scan session of a page locked table or an index before Adaptive Server attempts to promote from page locks to a table lock.
The page lock promotion LWM sets the number of page locks below which Adaptive Server does not attempt to issue a table lock on an object. The page lock promotion LWM must be less than or equal to page lock promotion HWM.
For more information on scan sessions and setting up lock promotion limits, see “Configuring locks and lock promotion thresholds” in the Performance and Tuning: Locking.
The default value for page lock promotion LWM is sufficient for most applications. If Adaptive Server runs out of locks (except for an isolated incident), you should increase number of locks. See the Performance and Tuning Guide for more information.
You can also configure page lock promotion at the per-object level. See sp_setpglockpromote in the Reference Manual: Procedures.
