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p.d.prasad
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Joined: 20 Jun 2006
Posts: 14
Location: hyderabad
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How many times secondary space allocated in VSAM ?
please explain this concept |
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SIVAMAIN
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Joined: 24 Jun 2006
Posts: 12
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in vsam 123 extents are allocated for secondary space.
example : tracks(5,5) means 5 tracks of primary, and 5 x 123 tracks of secondary space is allocated to the requested vsam dataset. |
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p.d.prasad
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Joined: 20 Jun 2006
Posts: 14
Location: hyderabad
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thanks for ur reply
but in one book i have seen that primary space allocated once and secondary space allocated 122 times.my doubt is
if the space allocated in primary block is not sufficient then it will go to secondary space so what is ment by that 122 times
ANY ONE CAN EXPLAIN YHIS FOR ME |
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Rupesh.Kothari
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Joined: 27 Apr 2005
Posts: 463
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Hi,
| Quote: |
my doubt is
if the space allocated in primary block is not sufficient then it will go to secondary space so what is ment by that 122 times |
If prilmary space full then can allocate 122 times the secondary space. Lets take an example, suppose u allocate (5,5) cylinder as primary and secondary.
If your VSAM uses first 5 cylinder and wants some extra space then it allocate first 5 Cylinder from Secondaey ans check is it sufficient if not then againg allocate 5 cylinder. It can goes till 122 times.
Hope it is clear now.
Thanks & Regards
Rupesh |
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Husna
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Joined: 02 Jun 2006
Posts: 49
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Rupesh,
In VSAM...
If we give CYL(5,5)..... It will take 615 CYL's ( 5+5*122)
In JCL
If we give CYL (5,5).... It will take 80 CYL's (5+5*15)
Could you please let me know both are correct or not? |
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Rupesh.Kothari
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Joined: 27 Apr 2005
Posts: 463
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Hi,'
Yes u r right. I believe for VSAM we never use CYL(5,5) in JCL. We define it when we create it only.
Correct me if I am wrong.
Regards
Rupesh |
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navneet.dewangan
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Joined: 09 Oct 2005
Posts: 22
Location: INDIA
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hello buddies in this disucssion can some one tell me about calculation of CISZ what will be the default parameter and where from the default parameters are taken..
i am not geting what will the control interval size .
what will be the length of the lsots in rrds.
can any one help me out . |
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p.d.prasad
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Joined: 20 Jun 2006
Posts: 14
Location: hyderabad
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hi navneet ,
i have some information for u.
the size of control interval should be a multiple of 512 or 2048 bytes depending upon the type of catalog.
default cisz is calculated by VSAM.
but generally for sequential processing
CISZ is 8K(8192)
FOR RANDOM PROCESSING
CISZ is 4k(4096).
MAXIMUM RECORD SIZE IS 32767 BYTES.
ANY ONE CAN CORRECT ME IF IAM WRONG. |
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