relative concept with vsam?



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relative concept with vsam?

Postby lxw039 » Mon Nov 24, 2008 11:46 pm

can anybody explain the defference between vsam and non-vsam? PDS and catalog?
is non-vsam Isam? thank you very much!
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Re: relative concept with vsam?

 

Re: relative concept with vsam?

Postby dick scherrer » Tue Nov 25, 2008 3:50 am

Hello,

can anybody explain the defference between vsam and non-vsam?
Somewhat self-explanitory (unless i misunderstand somthing with the question). If it is not vsam, it is non-vsam. The difference is that vsam is vsam and the others are not. . .but in'm not sure that is what you are asking :?
is non-vsam Isam?
Well, ISAM is non-vsam. . . Everything not vsam is "non-vsam". ISAM is an older technology that was basically replaced by VSAM.
PDS and catalog?
A PDS is a Partitioned Data Set. A catalog keeps track of datasets.
Hope this helps,
d.sch.
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Re: relative concept with vsam?

Postby lxw039 » Tue Nov 25, 2008 7:35 pm

thanks, Mr. d.
my realy meaning is what benifit we have to create vsam file,
lxw039 wrote:A PDS is a Partitioned Data Set. A catalog keeps track of datasets.

can I say PDs is a file, catalog is a directory?
thanks again!
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Re: relative concept with vsam?

Postby dick scherrer » Wed Nov 26, 2008 2:08 am

Hello,

One of the big benefits of a vsam file is the ability to define multiple keys and access the file randomly by any of the keys.

can I say PDs is a file
Yes, a pds is a file, but a special type of file (it has partioned organization - PO).

catalog is a directory?
Basically, yes. It is a directory of where datasets are cataloged (on which volser(s)).
Hope this helps,
d.sch.
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