Operating OnLine 3-69

Monitor Checkpoints

tbstat -R

Executetbstat -R to obtain information about the number of buffers in each
LRU queue and the number and percentage of the buffers that are modified.
Details about the function of theLRU queues are described on page2-57.
Refer topage 7-95 for further information about the tbstat -R output.

tbstat -D

Executetbstat -D to obtain, by chunk, the number of pages read and the
number of pages written.
Refer topage 7-86 for further information about the tbstat-D output.
Monitor Checkpoints
Monitor checkpoint activity to determine if your checkpoint interval
(specified asCKPTINTVL in the configuration file) is appropriate for your
processing environment.
From DB-Monitor
FromDB-Monitor, select the Status menu, Profile option.
TheCheckpoints field lists the number of checkpoints that have occurred
since OnLine was brought online.
TheCheck Waits field defines the number of times that a user process (any
user process) waits for a checkpoint to finish. A user process is prevented
fromentering a critical section during a checkpoint. For further information
about critical sections, refer topage 2-28.
Refer topage 3-83 for a complete explanation of the Profile option.
From DB-Monitor, select the Force-Ckpt menu.
Thedisplay lists the time of the last checkpoint and the last time that OnLine
checked to determine if a checkpoint was needed.