Re: Efficiency

Discussion created by ca.portal.admin on Jun 17, 2008
Hi Allen:

The answer to your question depends on what you consider ""efficiency"".
There is probably some via overflow in the set if the area is 83% full. You
are also likely to be incurring the overhead of space management activity,
which (by default) is triggered by pages that reach 70% fullness.

Expanding the area page size (XPAG) won't relocate any records, so you would
still have to read the same number of pages for the set, so this doesn't
create any 'efficiency'.
An unload/reload into a larger area will relocate the records, and ""tend"" to
reduce overflows if the new area is larger than the old one. Whether you
choose 55% or 65% 'fullness' will depend on your knowledge of the actual set
ratios to determine which one would provide the best data 'spread'. Given
that 65% is close to the 70% space management 'trigger', if you are going to
add many new records to the area, you'll probably want to choose 55% as the

Please note also that the members are stored VIA the owner occurence. If
you have some densely populated pages, any new records that are targeted to
be stored on those pages will likely become new 'overflows', depending on
how much new data is added to the area. If the area containing the ""owner""
records contains owner overflows, you'll want to consider doing an
unload/reload of that area also for proper data balancing.


Tom Schoenborn

p.s. I extend my personal best wishes to all in Iowa (and other states) who
have suffered from all the weather-related ills...

----- Original Message -----
From: ""Riddle, Allen [IDR]"" <Allen.Riddle@IOWA.GOV>
Sent: Tuesday, June 17, 2008 2:27 PM
Subject: Efficiency


We have a large area that contains only one record type and the records
are stored VIA. Currently, the area is 83% full and we are looking to
expand the area to bring that down. Will the area really become more
efficient if we drop it to say 55% as opposed to 65%? We are thinking
that the efficiency will stay the same because there are no CALC records
in the area.

Thank you in advance for any help you may be able to provide.


Allen Riddle

Department of Revenue

State of Iowa

(515) 281-3973
IDMS Public Discussion Forum


Re: Efficiency
"Good answer Tom,

Allen, if you posted a DBAN of both the Calc owner area and the member area
we could probably answer the question and even suggest the page count and
size for your unload/reload if needed.

Art Walker