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How can we calculate the BLKSIZE for Variable Block

 
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Husna

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Joined: 02 Jun 2006
Posts: 49

PostPosted: Wed Aug 30, 2006 8:59 am    Post subject: How can we calculate the BLKSIZE for Variable Block
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Hi all,

I have small doubt in the DCB Parameter. Any one of you please clarify the same?


Fixed Block
-------------
// RECFM=FB,LRECL=80,BLKSIZE=9040
This dataset will have fixed length records with a length of 80. There will be 113 records of data per block.

BLKSIZE/LRECL = 9040/80 = 113 records of data per block

Note: Multiple's of LRECL is BLKSIZE (80*113=9040)

Variable Block
--------------
// RECFM=VB,LRECL=255,BLKSIZE=3120
This dataset will have variable length records with a maximum of 255 characters. The blocksize of the dataset will be 3120.


Here, I am unable to understand this BLKSIZE concept. Here, BLKSIZE =3120 (But, it is not multiple's of 255). How can we calculate the BLKSIZE for Variable Block? Could you please let me know the same?
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priyesh.agrawal

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Joined: 28 Mar 2005
Posts: 1452
Location: Chicago, IL

PostPosted: Wed Aug 30, 2006 10:19 am    Post subject: Re: Doubt in DCB Parameter?
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Husna,

Quote:
I am unable to understand this BLKSIZE concept. Here, BLKSIZE =3120 (But, it is not multiple's of 255).

In case of VB, its not necessary for BLKSIZE to be a multiple of LRCEL.
It should be either same as or greater than LRECL in case of VB recs.
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Husna

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Joined: 02 Jun 2006
Posts: 49

PostPosted: Wed Aug 30, 2006 10:27 am    Post subject:
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Hi Priyesh,

Thanks...
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Dariusz
Warnings : 1

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Joined: 11 Aug 2005
Posts: 27
Location: POLAND

PostPosted: Wed Aug 30, 2006 3:45 pm    Post subject: VB records.
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Hi.
For VB records minimal BLKSIZE must be equal LRECL+4.
Regards.
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