page lock promotion LWM and row lock promotion LWM set a minimum number of locks allowed on a table before Adaptive Server attempts to acquire a table lock. The default value is 200. Adaptive Server never attempts to acquire a table lock until the number of locks on a table is equal to the low water mark.
The low water mark must be less than or equal to the corresponding high water mark.
Setting the low water mark to a very high value decreases the chance for a particular task or worker process to acquire a table lock, which uses more locks for the duration of the transaction, potentially exhausting all available locks in Adaptive Server. This possibility is especially high with queries that update a large number of rows in a datarows-locked table, or select large numbers of rows from datarows-locked tables at isolation levels 2 or 3.
If conflicting locks prevent lock promotion, you may need to increase the value of the number of locks configuration parameter.