13. Understanding the Locking System : How the Locking System Works : How the Locking Level is Determined : Methods for Changing How Locking is Handled
 
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Methods for Changing How Locking is Handled
The following methods can be used to change how Ingres handles locking:
• Set the system_lock_level parameter in the DBMS Server component in CBF. This parameter sets the default locking level for an entire Ingres instance. The system administrator can override the default system_lock_level default, which is set to DEFAULT.
Other valid values are:
– ROW
– MVCC
– PAGE
– TABLE
Each of the default lock levels other than TABLE is subject to escalation.
For details on the default behavior, see How the Locking Level is Determined (see page How the Locking Level is Determined).
Use the SET LOCKMODE statement to change parameters that determine how locking is handled. For example, using MAXLOCKS can reset the maximum number of logical locks that can be requested per table per query before escalating to a table-level lock.
Note:  The SET LOCKMODE statement cannot be issued in a transaction.
For details, see User-Controlled Locking (see page User-Controlled Locking--SET LOCKMODE).