topic Re: scheduler vss.dat maintaince in Operating System - OpenVMS

scheduler vss.dat maintaince

Ian Miller. — Mon, 10 Nov 2003 10:27:19 GMT

the product formally known as decscheduler has a indexed file called vss.dat that requires periodic maintaince. There is a supplied utility DB_UTILITY.EXE that does the maintaince if run interactively. I intend to have a regularly scheduled batch job that performs the maintaince regularly. I have found that a CONVERT operation does the trick. At present the steps are essentially
ANAL/RMS/FDL=A.FDL VSS.DAT
EDIT/FDL/ANAL=A.FDL/NOINTERACT A.FDL
CONVERT/FDL=A.FDL VSS.DAT VSS.DAT

However I was wondering about the EDIT/FDL and if a /SCRIPT=OPTIMIZE would be a good idea and if so if a /EMPHASIS=x qualifer would be a good thing?

Any comments?

Re: scheduler vss.dat maintaince

Ian Miller. — Mon, 10 Nov 2003 10:33:04 GMT

re-reading the help it appears /NOINTERACTIVE invokes the optimize script. However I'm still wondering about /EMPHASIS

Re: scheduler vss.dat maintaince

Lokesh_2 — Mon, 10 Nov 2003 11:08:36 GMT

Hi Ian,

you can use the following command procedure to run DB_UTILITY in batch job
**************************************
sys> type a.com
$set noon
$sch stop
$run nsched$:db_utility
yes
$@sys$startup:scheduler$startup
$exit
*****************************************

Thanks & regards,
Lokesh

Re: scheduler vss.dat maintaince

Hein van den Heuvel — Mon, 10 Nov 2003 11:44:53 GMT

I'm reasonably comfortably with tuning RMS indexed files in general, but unfortunately do not know anything about this vss.dat file or its specific usage?

Is it even worth worrying about? Like does it have several operations/second? How is the IOs/record operation looking?

You may want to use my rms_stats and/or rms_tune_check tools from the VMS freeware kit to help understnad how critical it is to tune this file a little, or a lot.

http://h71000.www7.hp.com/freeware

Please also define 'period'? How much effort is the ANAL/RMS phase? Is this done daily/weekly?

I would encourage you to review the analyze output yourself, tweak it to cover your anticipated usage for the next N periods (notably the total number of records expected) and skip the analyze and optimize for several periods (a year). Just use a well tuned FDL over and over, untill (runtime) stats suggest further action is needed.

Hope this helps,
Hein.