Specifying the default maximum number of locks per table space

The NUMLKTS subsystem parameter specifies the default value at the subsystem level for the LOCKMAX clause of CREATE TABLESPACE and ALTER TABLESPACE statements.

Procedure

  • Set the NUMLKTS subsystem parameter value.

    In most cases, you can use the default or continue using the existing value if you are migrating from a previous Db2 release. The NUMLKTS value should be less than the value for the NUMLKUS subsystem parameter, unless the value of the NUMLKUS subsystem parameter value is 0.

    When a thread hits this limit, it does not fail. Instead, the thread stops acquiring individual row locks, and lock escalation converts the existing child locks into a gross lock on the entire partition or table space. The also lock escalation occurs without Db2 issuing a message to report the situation.

  • When you create or alter a table space, especially when you alter one to use row locks, use the LOCKMAX clause explicitly for that table space.End program-specific programming interface information.