
Example of parsing mdb randomic query bench trace (test explained in
more detail at http://www.linux-mm.org/PageReplacementTesting):

# file captured with "vmtrace-capture":
$ ls -la /tmp/vmt.txt
-rwxrwxrwT  1 root root 1338372 2005-12-12 18:29 /tmp/vmt.txt

# split it into per-mapping traces
$ ./vmtrace-split /tmp/vmt.txt /tmp/mdb-rand/

# format is <inode_nr,bdev>
$ ls /tmp/mdb-rand/
0-0      65c72-0  7ec2-0   aa54c-0  d9fd7-0
65c71-0  65c75-0  aa527-0  aaaf9-0  e5d01-0

$ for i in /tmp/mdb-rand/* ; do ./vmtrace-irp $i ; done | grep IRF
/tmp/mdb-rand/0-0: avg. IRF of all reaccessed pages(33): 12.949683
/tmp/mdb-rand/65c71-0: avg. IRF of all reaccessed pages(1808): 0.011185
/tmp/mdb-rand/65c72-0: avg. IRF of all reaccessed pages(176): 0.092401
/tmp/mdb-rand/65c75-0: avg. IRF of all reaccessed pages(16): 1.171296
/tmp/mdb-rand/7ec2-0: avg. IRF of all reaccessed pages(1): 0.000079
/tmp/mdb-rand/aa527-0: avg. IRF of all reaccessed pages(65): 0.038615
/tmp/mdb-rand/e5d01-0: avg. IRF of all reaccessed pages(6): 0.878549

The most interesting numbers here are:

65c71 is largedb.dat (7440358 bytes)
65c72 is largedb.idx (720896 bytes)
/tmp/mdb-rand/65c71-0: avg. IRF of all reaccessed pages(1808): 0.011185
/tmp/mdb-rand/65c72-0: avg. IRF of all reaccessed pages(176): 0.092401 

Which means that the index file is accessed about 9 times more frequently
than the data file itself.

The text mapping of the "mdb" binary (at address 0) is much more
frequently accessed than both database files:

/tmp/mdb-rand/0-0: avg. IRF of all reaccessed pages(33): 12.949683

