DB2 initialization parameters

Some of the DB2 parameters you might want to alter to work with your ArcSDE geodatabase are as follows:

Parameters that affect locks

Deadlocks may not be uncommon, depending on the client application and the database configuration. Note that the problem may be aggravated with deep states lineages. Fortunately, DB2 provides tuning parameters to control the size of the lock list (LOCKLIST), the maximum percentage of locks an application can hold (MAXLOCKS), the amount of time a request will wait for a lock to be acquired (LOCKTIMEOUT), the frequency interval for deadlock detection (DLCHKTIME), and deadlock rollback behavior (DB2LOCK_TO_RB).

The default value for LOCKLIST and MAXLOCKS in DB2 9 is AUTOMATIC, which enables these parameters for self tuning. This allows the DB2 memory tuner to dynamically size the memory resources between different memory consumers. Automatic tuning only occurs if self-tuning memory is enabled for the database (SELF_TUNING_MEM=ON).

To view lock list settings, issue the following command:

db2 get db cfg

Max storage for lock list (4KB)		(LOCKLIST) = 50
Interval for checking deadlock (ms)	(DLCHKTIME) = 10000
Percent. of lock lists per application	(MAXLOCKS) = 22
Lock time out (sec)			(LOCKTIMEOUT) = -1
Max number of active applications	(MAXAPPLS) = AUTOMATIC

For the DB2LOCK_TO_RB registry value, use db2set and look for DB2LOCK_TO_RB=.

For more information on setting these parameters, see Deadlocks in a DB2 database.

See the DB2 documentation or performance tuning guides for detailed information on properly setting these parameters.