Using Process Memory Matrix script for calculating Oracle process memory usage on Solaris

Tanel Poder

2010/02/11

I just published a new script and article about calculating the real Oracle process memory usage on Solaris.

The problem with V$PROCESS* views (and the V$SESSTAT) is that they will tell you what Oracle thinks it’s using, not the real amount of memory used. There will be discrepancies due how memory is actually allocated in OS, libraries out of Oracle’s control, the static memory areas inside Oracle binary and of course bugs.

I was working on one of such problems and decided to make my life easier by writing the script. It’s not so much about calculating the exact figures (they will never be 100% correct), but more about presenting the memory usage data in a better and more convenient fashion.

The script is called procmm and stands for Process Memory Matrix as it shows the memory usage in a matrix grid.

Here’s an example output to show what I’m talking about:

oracle@solaris02:~/research/memory$ ./procmm.sh -t `pgrep -f ora_.*SOL102`

-- procmm.sh: Process Memory Matrix v1.01 by Tanel Poder ( http://tech.e2sn.com )
-- All numbers are shown in kilobytes

Total PIDs 17, working: .................

PID            SEGMENT_TYPE      VIRTUAL          RSS         ANON       LOCKED    SWAP_RSVD
------ -------------------- ------------ ------------ ------------ ------------ ------------
0                       lib       389844       388796        13180            0        17816
0                    oracle      1629064      1628908         3336            0        42012
0            ism_shmid=0x1d      6963336      6963336            0      6963336            0
0             hc_SOL102.dat           48           48            0            0            0
0                      anon        32936        15936        15452            0        32868
0                     stack         1660         1628         1592            0         1660
0                      heap        37004        18016        16844            0        37004
------ -------------------- ------------ ------------ ------------ ------------ ------------
0                 TOTAL(kB)      9053892      9016668        50404      6963336       131360

And here’s the full article and in there a link to the script:

Comments are welcome here, as I haven’t set up commenting on my other site yet…