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sushanth bobby
Senior Member
Joined: 29 Jul 2008
Posts: 1013
Location: India
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Hi,
I prepare a DB2 Extent report that looks like this...
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DBNAME TSNAME PQTY-Allocated PQTY-USED SQTY-A SQTY-U E X T E N T S
(TRKS) (TRKS) (TRKS) (TRKS) TAKEN REMAIN
dbname tsname 2085 2085 3780 3619 27 8 |
The table in this tablespace has 982,782 records and row length is 189.
Since primary(allocated & used) are in tracks. I calculated the size of the tablespace, taking following into condsideration.
16,384 cylinders/ disk
80 heads / cylinder
63 sectors / track
512 bytes / sector
I have calculated the following
Tracks = 2085
2085* 63 =131355 (Sector)
131355*512 =67253760 (bytes)
67253760/1024 =65677.5(kb)
65677.5/1024 =64.13 (gb)
Can i take 64.13GB as the tablespace size or my calculations are wrong. |
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Prasanthhere
Active User
Joined: 03 Aug 2005
Posts: 306
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When I did the Volumetrics using a tool the tablespace size is coming only up to 96M
I don't think the table space size will be this much large (64.13 Gb) for JUst 982,782 records.
You need to take to your DBA to determinge the exact size specing the row count, row count growth, record length etc . |
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sushanth bobby
Senior Member
Joined: 29 Jul 2008
Posts: 1013
Location: India
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Hi prasanth,
I googled & Googled, i got this link. Using this link i started my calculation. Is there any other way to calculate the size. Formulas anything... Is there any....
http://www.rwc.uc.edu/koehler/comath/42.html |
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enrico-sorichetti
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Joined: 14 Mar 2007
Posts: 10277
Location: italy
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You used some device characteristics which do not apply for example to 3390
I would stick to a simple count from the db2 side to get the bytes/Kbytes/Mbytes/Gbytes needed
and forget about the device geometry |
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sushanth bobby
Senior Member
Joined: 29 Jul 2008
Posts: 1013
Location: India
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Enrico,
| Quote: |
| You used some device characteristics which do not apply for example to 3390 |
My device type is also 3390 only. So, the calculations are entirely wrong.hmmmm..
| Quote: |
| I would stick to a simple count from the db2 side to get the bytes/Kbytes/Mbytes/Gbytes needed |
Are you talking about calculating like this.
Total number of records in the database * size of a single record. |
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Prasanthhere
Active User
Joined: 03 Aug 2005
Posts: 306
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Hi Sushanth,
First of all your calculation is wrong..
| Quote: |
67253760/1024 =65677.5(kb)
65677.5/1024 =64.13 (gb)
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Actually the values would be like this only if I use your calcualtion
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bytes 67253760
kilobytes 65677.5
megabits 513.10546875
megabytes 64.13818359375
gigabits 0.501079559326172
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Means .5GB of space only and not 64.13
[/quote] |
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sushanth bobby
Senior Member
Joined: 29 Jul 2008
Posts: 1013
Location: India
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Prasanth,
Oh my. I never thought, i would be making such a careless fundamental mistake. Thank You Very Much.....
| Quote: |
| First of all your calculation is wrong.. |
You are telling my entire formula calculation is wrong, RIGHT.
And as enrico was telling table size can calculated by,
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| table size=row length*number of records. |
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Prasanthhere
Active User
Joined: 03 Aug 2005
Posts: 306
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| Quote: |
You are telling my entire formula calculation is wrong, RIGHT
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I was just mentioning that 64.13 GB was wrong |
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sushanth bobby
Senior Member
Joined: 29 Jul 2008
Posts: 1013
Location: India
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Hi,
Ohh, OK.
Enrico was saying,
| Quote: |
| You used some device characteristics which do not apply for example to 3390 |
Do you know anything about this..... Because, all these calculations are for oridinary Hard Disk.
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16,384 cylinders/ disk
80 heads / cylinder
63 sectors / track
512 bytes / sector |
Does mainframe use different type Hard Disks for their storage and their characteristic are entirely different.
Because, if this is true. My calculation will be WRONG. |
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