Hi!
Just checked one of our databases and found that number of MTL_OM latches is pretty high:
_Latch-Name _Latch-Lock _Latch-Wait latch/secMTL_OM 4483906701 6844 4,483,906,701MTL_OM 4483914640 6844 7,939MTL_OM 4483922014 6844 7,374MTL_OM 4483927715 6844 5,701MTL_OM 4483933176 6844 5,461MTL_OM 4483937684 6844 4,508MTL_OM 4483941763 6844 4,079MTL_OM 4483948088 6844 6,325MTL_OM 4483969421 6844 21,333MTL_OM 4484037072 6844 67,651MTL_OM 4484104383 6844 67,311MTL_OM 4484112012 6844 7,629MTL_OM 4484117447 6844 5,435MTL_OM 4484185073 6844 67,626MTL_OM 4484206032 6844 20,959MTL_OM 4484327023 6844 120,991MTL_OM 4484353623 6844 26,600
Actual number of _storageobject records is 1600.
Should I set -omsize to 2048 and expect something? Lower load? Increase in speed?
Because of nature of our systems, it's almost impossible to set up full proper test environment, so I can change parameters only in production system.
wbr,
Toomas
Experience is what you get when you don't get what you want.
_Latch-Name _Latch-Lock _Latch-Wait latch/sec MTL_OM 4483906701 6844 4,483,906,701 MTL_OM 4483914640 6844 7,939 MTL_OM 4483922014 6844 7,374 MTL_OM 4483927715 6844 5,701 MTL_OM 4483933176 6844 5,461 MTL_OM 4483937684 6844 4,508 MTL_OM 4483941763 6844 4,079 MTL_OM 4483948088 6844 6,325 MTL_OM 4483969421 6844 21,333 MTL_OM 4484037072 6844 67,651 MTL_OM 4484104383 6844 67,311 MTL_OM 4484112012 6844 7,629 MTL_OM 4484117447 6844 5,435 MTL_OM 4484185073 6844 67,626 MTL_OM 4484206032 6844 20,959 MTL_OM 4484327023 6844 120,991 MTL_OM 4484353623 6844 26,600
Flag this post as spam/abuse.
code to check:
define variable prev-latches as integer.
repeat:
find _latch where _latch-name = "MTL_OM".
display _Latch-Name
_Latch-Lock /* # times latch acquired */
_Latch-Wait /* # time conflict occurred */
_Latch-Lock - prev-latches label "latch/sec".
prev-latches = _Latch-Lock.
pause 1.
end.
code to figure out what to set -omsize to:
select count(*) from _storageobject.
the number of storage objects you have is how many object mappings you need. allow some (say 15% or 20%) extra for headroom.
gus --
So is that resulting number of objects (from "select count...") what you set the -omsize to, or do you have ti multiply by some mem size constant like 1024k to get the actual parameter you need?