Operating OnLine 3-109

Change the Checkpoint Interval

From the Command Line
From the command line, execute thetbparams utility with the following
options and parameters:
Only the-p option is required. The following example changes the size and
location of the physical log and reinitializes shared memory so the change
takes effect immediately:
tbparams -p -s 400 -d dbspace5 -y
If you reinitialize shared memory, create a level-0 archive to ensure that all
recovery mechanisms are available.
Change the Checkpoint Interval
This section provides instructions for changing the checkpoint interval. The
checkpoint interval is specified byCKPTINTVL in the configuration file.
Thecheckpoint interval is not necessarily the amount of time between check-
points. The interval describes the maximum amount of time that can elapse
before OnLine checks to determine if a checkpoint is needed. If no changes
have been made to OnLine data, the checkpoint check is recorded but the
checkpoint is not performed.
The value of CKPTINTVL is expressed in seconds. The default value is 300
seconds or five minutes.
You can make this change while OnLine is in online mode, but the changes
do not take effect until you reinitialize shared memory (take OnLine offline
and then to quiescent or online mode).
Ifyou are logged in as user informix or root, you can make this change from
the command line. You cannot make this change from withinDB-Monitor.
-p changes the physical log.
-ssize specifies the size of the physical log in kilobytes.
-d dbspace specifies the dbspace where the physical log resides.
-y initializes shared memory immediately.