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niks_jude
Warnings : 1
Active User
Joined: 01 Dec 2006
Posts: 144
Location: Mumbai
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Is it necessary that for a file with RECFM=F, the blocksize would be required to be equal to LRECL?
Two thing I would like to mention additionally -
1) I tried the manual but could not find any information about this.
2) I tried RECFM=F PS files with different LRECL without giving blocksize and their Blocksize was equal to the LRECL. |
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enrico-sorichetti
Superior Member
Joined: 14 Mar 2007
Posts: 10873
Location: italy
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You are asking about recfm F ...
==> record format fixed ...
==> unblocked...
==> LRECL = BLKSIZE
as per specifications
( ==> stands for implies ) |
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niks_jude
Warnings : 1
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Joined: 01 Dec 2006
Posts: 144
Location: Mumbai
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| Ok. So that means the blocksize for a RECFM=V file is the largest LRECL. |
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srinathangya
New User
Joined: 19 Dec 2005
Posts: 77
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Hi there.. Whether LRECL and BLKSIZE shud be equal or different depends upon the type of application u r using. Blocks are the unit of information transferred between DASD and buffer. If U r using a sequential file, then it is recommended to have block size to be as big as possible. This reduces the data transfer time. If U r using say an Index file, where, U pick the record depending upon the key value, it is better to go with the LRECL and Blksize the same. If U r unsure better leave LRECL and BLKSIZE with the same value.
Hope i havent said anything wrong :-) |
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dick scherrer
Moderator Emeritus
Joined: 23 Nov 2006
Posts: 19244
Location: Inside the Matrix
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Hello,
| Quote: |
| So that means the blocksize for a RECFM=V file is the largest LRECL. |
Yes, however recfm=v is seldom used. Most variable files are VB and then blksize is usually not the largest lrecl. |
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Frank Yaeger
DFSORT Developer
Joined: 15 Feb 2005
Posts: 7129
Location: San Jose, CA
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Hmmm ... I was under the impression that for a VB file, the BLKSIZE must be at least LRECL+4 to allow for the 4-byte BDW. I thought that was true for RECFM=V as well. Not so for one or both?
I tried some experiments and couldn't actually write records into a file with RECFM=V,LRECL=80,BLKSIZE=80. If I specified that for IEBGENER's SYSUT2 and then used DFSORT to display it, it showed the BLKSIZE as 84. |
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dick scherrer
Moderator Emeritus
Joined: 23 Nov 2006
Posts: 19244
Location: Inside the Matrix
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Hello,
| Quote: |
| I was under the impression that for a VB file, the BLKSIZE must be at least LRECL+4 to allow for the 4-byte BDW. I thought that was true for RECFM=V as well. Not so for one or both? |
Yup, true for both.
My answer was a bit incomplete 
d |
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