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Sonal Jadhao
New User
Joined: 03 Apr 2008
Posts: 5
Location: Chennai
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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
Active Member
Joined: 06 Sep 2007
Posts: 792
Location: Chennai, India
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Sonal,
| Quote: |
| Here directory block is 5 , so how many members can it have? |
25
one directory block for 5 members... |
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expat
Global Moderator
Joined: 14 Mar 2007
Posts: 8797
Location: Welsh Wales
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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
Superior Member
Joined: 14 Mar 2007
Posts: 10873
Location: italy
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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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