System Optimization

[Joe Boyle]

You mention Quiz specifically; do you also have issues with writes and
rewrites to the files in terms of time taken to complete ? If so, this could
be due to heavily repeating keys, and would be helped by archiving off as
much data as possible ( followed by a rebuild).

It might be worth rebuilding one or two files using FDL utilities. If there
are significant size differences in the 'before' and 'after' files, this
would suggest that there are lots of logical deletes in the files which
might be slowing things down. 

If there are large subfiles being created, it might be worth pointing them
at a disk with plenty of free disk space, as RMS may be spending lots of
time searching for free block allocations if the disk is heavily allocated. 

If the data clusters are very segmented over the disk, this would also slow
down disk head reads, and once again a rebuild on a 'clean' disc might help
improve performance. 

You could even run an analyse on the file data block distribution, and if
you have someone with RMS data file structure knowledge, they might be able
to tweak the data block allocations for the various index and data levels,
which might also speed things up.


-----Original Message-----
From: powerh-l-bounces+atla38=dsl.pipex.com at lists.sowder.com
[mailto:powerh-l-bounces+atla38=dsl.pipex.com at lists.sowder.com] On Behalf Of
Ken Langendock
Sent: 22 January 2007 22:03
To: powerh-l at lists.sowder.com
Cc: 'Desmond Dujon'
Subject: RE: System Optimization

Adding the VIAINDEX may help you but remember you will have to remove
them if you go to any other database/platform.
Forcing the index path is not efficient if you are planning on changing
to a relational db.

Optimizing the tables is a good bet. Keeping the number of indexes to a
minimum and using segmented indexes helps.
Ken


-----Original Message-----
From: powerh-l-bounces+ken.langendock=rogers.com at lists.sowder.com
[mailto:powerh-l-bounces+ken.langendock=rogers.com at lists.sowder.com] On
Behalf Of Darren Reely
Sent: January 22, 2007 4:50 PM
To: powerh-l at lists.sowder.com
Cc: Desmond Dujon
Subject: Re: System Optimization


It has been 10 years, so my memory is a little vague. One important 
lesson I learned was to reference your indexes. Don't rely on the 
compiler doing the right thing.

I once was trying to figure out why a report was taking 2.5 hrs to run. 
When I looked at the code it was obvious. The coder of the Quiz program 
did not specify which indexes to use. I added index specifiers with the 
'VIAINDEX' structure and the report ran in under 15 minutes.

I used to also have the systems guy optimize my tables every once in a 
while. This helped the above mentioned report a few times until I could 
take a look at the code. It saved maybe 20% of the run time. I really 
don't remember any details of what they did.

Darren

Desmond Dujon wrote:
> Hi folks.Happy new year.
>
> Are there any commands /parameter changes ( apart from
> autogen) you can suggest to speed up performance on
> our ES47 Alpha server running OpenVMS 7.3 , Powerhouse
> 7.10.g3. Some of our quiz reports involve alot of
> calculationa , take hours to run and are very cpu
> intensive. Most of the files accessed (RMS files) are 
>  700,000 blocks and less. No database is used. 
>   
-- 
= = = = = = = = = = = = = = = = = = = = = = = = = = = =
Mailing list: powerh-l at lists.sowder.com
Subscribe: "subscribe" in message body to
powerh-l-request at lists.sowder.com
Unsubscribe: "unsubscribe <password>" in message body to
powerh-l-request at lists.sowder.com
http://lists.sowder.com/mailman/listinfo/powerh-l
This list is closed, thus to post to the list you must be a subscriber.
Add 'site:lists.sowder.com powerh-l' to your search terms to search the
list archive at Google.

-- 
= = = = = = = = = = = = = = = = = = = = = = = = = = = =
Mailing list: powerh-l at lists.sowder.com
Subscribe: "subscribe" in message body to
powerh-l-request at lists.sowder.com
Unsubscribe: "unsubscribe <password>" in message body to
powerh-l-request at lists.sowder.com
http://lists.sowder.com/mailman/listinfo/powerh-l
This list is closed, thus to post to the list you must be a subscriber.
Add 'site:lists.sowder.com powerh-l' to your search terms to search the list
archive at Google.