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SPACE parameter

 
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Sonal Jadhao

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Joined: 03 Apr 2008
Posts: 5
Location: Chennai

PostPosted: Mon Apr 14, 2008 7:12 pm    Post subject: SPACE parameter
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Where do we mention about the number of members for each directory block mentioned in the SPACE parameter?
eg. SPACE=(TRK(10,20,5))

Here directory block is 5 , so how many members can it have? What is Default ?
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Gnanas N

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Joined: 06 Sep 2007
Posts: 788
Location: Chennai, India

PostPosted: Mon Apr 14, 2008 7:17 pm    Post subject:
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Sonal,
Quote:
Here directory block is 5 , so how many members can it have?

25
Quote:
What is Default ?

one directory block for 5 members...
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expat

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Joined: 14 Mar 2007
Posts: 8593
Location: Back in jolly old England

PostPosted: Mon Apr 14, 2008 7:52 pm    Post subject:
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Quote:
one directory block for 5 members...


The correct answer is actually 6, the first block contains control information, so only allows for 5 members with ISPF stats on.

So with 5 DB's you will get 29 members with ISPF stats on.

It's a bit like the first track will only contain 44 directory blocks, while all subsequent tracks will contain 45.
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enrico-sorichetti

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Location: italy

PostPosted: Mon Apr 14, 2008 8:07 pm    Post subject: Reply to: SPACE parameter
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a directory block is 256 bytes...
how many members will fit depends ...

each entry has the following layout

8 bytes for the member name
3 bytes for the TTR ( 2 bytes for the track 1 byte for the record ) offset
1 byte for flags and the length of the user data

for load dataset, I will have to look it up ( some load module related info is contained in the user data part of the directory entry)

for fb datasets the emtry size depends on the ispf statistics being there or not
each entry will be
12 bytes without statistics
42 bytes with statistics
the ispf statistics are 15 halfords, 30 bytes

so each directory block will contain ..
21 entries without statistics
6 entries with statistics

anything between for the mixed case...
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