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Home -> Community -> Mailing Lists -> Oracle-L -> RE: New Table Sizing ... but whhhyyyy???
well kathy .. i am happy to hear about your organisation ...
>>forecast figures are NOT based on some marketing geek's
really .. ok .. if you insist .. everyday i learn something new!!
>> sizing and estimating is part of my job description.
sizing and estimating table size based on what !! growth projections right !! do you also do market study and trend analisis and project that you will have "x" # of customers .. maybe you do .. so ok .. good for you :-)) well we dont cause we have full time senior folks devoted to that alone !! In our case .. the base of our capacity plan is inputs what we recieve from the these people (mktg team and management) .. we translate that into oracle numbers and give a safety net of 15-25% .. (we've also ordered a lots of TB's based upon these for a rainy day)
deepAk
PS: btw the name is deepak . (Thay .. hmm:-)))
-----Original Message-----
From: kathy.wright_at_southtrust.com [mailto:kathy.wright_at_southtrust.com]
Sent: Wednesday, July 12, 2000 11:02 AM
To: Thapliyal, Deepak
Cc: Trace_R_Jones_at_reliantenergy.com; oracledba_at_quickdoc.co.uk
Subject: RE: New Table Sizing ... but whhhyyyy???
Thay -
I'm sure you meant no harm in your response, but there ARE organizations in
this
world
who do accurately project and size database growth. I work for one of the
largest banks
in the southeast and the forecast figures are NOT based on some marketing
geek's
figures. Data sizing and estimating is part of my job description. I
take it
seriously and
do it well. Tables can always be dropped and rebuilt if the growth is more
(or
less) than
what was forecasted.
FYI,
Kathy
-----Original Message-----
From: Thapliyal, Deepak
Sent: Wednesday, July 12, 2000 11:02 AM
To: 'kathy.wright_at_southtrust.com'; Trace_R_Jones_at_reliantenergy.com
Cc: oracledba_at_quickdoc.co.uk
Subject: RE: New Table Sizing ... but whhhyyyy???
so here I am with my precious $.01 again ...
guys and gals .. why make such a big fuss on always trying to accurately size overhead .. why .. why .. last time .. whyy:-))
as far as I see --> table size = (#rows * avg_row_len) + overhead
now we twist our brain cells trying to accurately figure out overhead crap .. the works .. but tell me .. what is the parameter in the above formula that has the greatest impact on the table size ... yup ya guessed it right --> #rows .. and who tells you this?? .. some smart mktg guy who projects that .. ok .. by FY01 there will be 2 million customers hitting ur site .. and we .. then assume that the customer table, for e.g., will be 2mill and then size appropriately ..
point in case .. when the parameter which most impacts table size (#rows) is a GUESS .. then why worry about those teeny weeny overheads.. therefore, whenever I have to do the capacity plan, I simply fill one record in a table (if its empty) .. analyze, get avgrowlen , multiply by #rows( ESTIMATED!!#%$@!!) and then add 10%-15% overhead and whallah .. I have a pratical .. real life sized table sizing .. now if there is unexpected growth .. we always have our traffic and n/w diagram to fall back on .. so that in future ... the mktg team makes some more meaningful analysis on expected site growth !!
deepAk
-----Original Message-----
From: kathy.wright_at_southtrust.com [mailto:kathy.wright_at_southtrust.com]
Sent: Wednesday, July 12, 2000 9:33 AM
To: Trace_R_Jones_at_reliantenergy.com
Cc: oracledba_at_quickdoc.co.uk
Subject: Re: New Table Sizing
Use this formula:
Here is an example table:
183 + 27 + 0 + 3 = 213 bytes
5) bytes available / bytes 14665 / 213 = 68.8 or 69 rows
per
6) estimate your rows per block - example of 150,000 rows
rows / rows per block = estimated size
150000 / 69 = 2173.9 round up to 2174k
size this example table as 2mg!
Great formula, pulled from the ORACLE 8 DBA HANDBOOK (Oracle Press)
Hope this helps,
Kathy
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