Monitor session memory with onstat -g mem and onstat -g stm output
Use the onstat -g mem and onstat -g stm commands to obtain information about the memory used for each session.
You can determine which session to focus on by the used memory column of the onstat -g ses output.
onstat
-g mem and onstat -g stm to determine
session memory shows sample onstat
-g ses output and some of the onstat -g mem and onstat
-g stm output for Session 16. Figure 1: onstat
-g mem and onstat -g stm to determine
session memory
- The output of the onstat -g mem command shows
the total amount of memory used by each session.
The totalsize column of the onstat -g mem 16 output shows the total amount of memory allocated to the session.
- The output of the onstat -g stm command shows
the portion of the total memory allocated to the current prepared SQL statement.
The heapsz column of the onstat -g stm 16 output in the following figure shows the amount of memory allocated for the current prepared SQL statement.
onstat -g ses
session #RSAM total used
id user tty pid hostname threads memory memory
18 informix - 0 - 0 12288 8928
17 informix 12 28826 lyceum 1 45056 33752
16 virginia 6 28743 lyceum 1 90112 79504
14 virginia 7 28734 lyceum 1 45056 33096
3 informix - 0 - 0 12288 10168
2 informix - 0 - 0 12288 8928
onstat -g mem 16
Pool Summary:
name class addr totalsize freesize #allocfrag #freefrag
16 V a9ea020 90112 10608 159 5
...
onstat -g stm 16
session 16 ---------------------------------------------------------------
sdblock heapsz statement ('*' = Open cursor)
aa0d018 10056 *SELECT C.customer_num, O.order_num
FROM customer C, orders O, items I
WHERE C.customer_num = O.customer_num
AND O.order_num = I.order_num