QIBM_SYSTEM_LIMITS global variables

To prevent excess storage consumption or retention of unnecessarily old system limits entries within the QSYS2/SYSLIMTBL table, Db2 for i will automatically delete (or prune) rows.

There are two ways the pruning is controlled. Start of changeOne method is by the number of days to keep a row.End of change The other is by the maximum number of rows to keep for a specific limit. In each case, Db2 for i supplied global variables guide the pruning action.

Controls exist for deleting rows that have reached a certain age are handled with a set of Db2 for i provided global variables. These controls cause rows to be removed when they exceed the number of days.

The following are the names of the global variables that control pruning by number of days and the limit that is shipped for each one. The schema is SYSIBMADM.

Global variable Shipped limit
QIBM_SYSTEM_LIMITS_ASP_BY_DAYS 90
QIBM_SYSTEM_LIMITS_JOB_BY_DAYS 90
QIBM_SYSTEM_LIMITS_OBJECT_BY_DAYS 90
QIBM_SYSTEM_LIMITS_SYSTEM_BY_DAYS 90

The second control for automatic deletion of rows is by the number of rows for a type of limit. For each type of limit, there are two global variables. The pruning variable is used to choose how many of the most recently logged entries should be retained. The high point variable is used to choose how many of the highest consumption value entries should be retained.

The following are the names of the global variables and the limit that is shipped for each one. The schema is SYSIBMADM.

Global variable Shipped limit
QIBM_SYSTEM_LIMITS_PRUNE_BY_ASP 20
QIBM_SYSTEM_LIMITS_PRUNE_BY_JOB 20
QIBM_SYSTEM_LIMITS_PRUNE_BY_OBJECT 20
QIBM_SYSTEM_LIMITS_PRUNE_BY_SYSTEM 20
QIBM_SYSTEM_LIMITS_SAVE_HIGH_POINTS_BY_ASP 25
QIBM_SYSTEM_LIMITS_SAVE_HIGH_POINTS_BY_JOB 5
QIBM_SYSTEM_LIMITS_SAVE_HIGH_POINTS_BY_OBJECT 5
QIBM_SYSTEM_LIMITS_SAVE_HIGH_POINTS_BY_SYSTEM 25

You can adjust any of the global variable values to establish a custom behavior for the automatic deletion of system limits rows. The Db2 for i supplied global variables use the default value to guide an automatic row deletion process that runs nightly when Collection Services is recycled, which normally occurs just past midnight.

Use IBM i Access Client Solutions (ACS) to generate SQL for the global variable and use the OR REPLACE option to recreate it with a different default. For example, to remove all object limits older than 30 days, use the following SQL statement:
CREATE OR REPLACE VARIABLE SYSIBMADM.QIBM_SYSTEM_LIMITS_OBJECT_BY_DAYS 
	INTEGER   
	DEFAULT 30