MINUTES/CHECKPOINT field (CHKFREQ and CHKMINS subsystem parameters)

The MINUTES/CHECKPOINT field determines the approximate number of minutes that are to pass between scheduled log checkpoints.

Acceptable values:	Depending on the CHECKPOINT TYPE value: CHECKPOINT TYPE is LOGRECS: NOT USED CHECKPOINT TYPE is MINUTES: 1 -5 CHECKPOINT TYPE is BOTH: 1 -5
Default:	3
Update:	option 42 on panel DSNTIPB
DSNZP`xxx`:	DSN6SYSP.CHKFREQ and DSN6SYSP.CHKMINS

1 -5 (if CHECKPOINT TYPE is MINUTES)

The number of minutes between checkpoints. The specified value is assigned to the CHKFREQ subsystem parameter value, and the CHKMINS subsystem parameter is set to NOT USED.

Start of change If you specify 6 - 60 for the CHKFREQ subsystem parameter setting, Db2 converts the value to 5 for the CHKFREQ setting, issues a warning message, and sets RC=4 for subsystem parameter assembly. End of change

NOT USED (if CHECKPOINT TYPE is LOGRECS)

NOTUSED is assigned to the CHKMINS parameter. (The CHKFREQ parameter is assigned the value specified for the RECORDS/CHECKPOINT field. See RECORDS/CHECKPOINT field (CHKFREQ and CHKLOGR subsystem parameters).)

1 -5 (if CHECKPOINT TYPE is BOTH)

The number of minutes between checkpoints. The specified value is assigned to the CHKMINS subsystem parameter value, and the CHKFREQ subsystem parameter is set to NOT USED.

Start of change If you specify 6 - 1439 for the CHKMINS subsystem parameter setting, Db2, converts the value to 5 for the CHKMINS setting, issues a warning message, and sets RC=4 for subsystem parameter assembly. End of change

Start of change Db2 prevents log checkpoints from being taken too frequently and degrading performance. Log checkpoints are scheduled, but not necessarily immediately taken, when the number of minutes that passes reaches the value of CHKMINS. End of change

The following table summarizes how the CHECKPOINT TYPE, MINUTES/CHECKPOINT, and RECORDS/CHECKPOINT fields on panel DSNTIPL1 set the related subsystem parameters to specify the Db2 checkpoint frequency. The following table shows panel DSNTIPL1 fields and related subsystem parameters for controlling the Db2 checkpoint frequency.

CHECKPOINT TYPE field	CHKTYPE subsystem parameter	CHKFREQ subsystem parameter	CHKMINS subsystem parameter	CHKLOGR subsystem parameter
MINUTES (default)	SINGLE	1 - 5 (default 3) Set in the MINUTES/CHECKPOINT field to specify the number of minutes between checkpoints.	NOT USED	NOT USED
LOGRECS	SINGLE	1000 - 16 000 000 Set in the RECORDS/CHECKPOINT field to specify the number of log records between checkpoints.	NOT USED	NOT USED
BOTH	BOTH	NOT USED	1 - 5 Set in the MINUTES/CHECKPOINT field to specify the number of minutes between checkpoints.	1000 - 99 999 999 Set in the RECORDS/CHECKPOINT field to specify the number of log records between checkpoints.