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About PS datasets


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Gnanas N

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Joined: 06 Sep 2007
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PostPosted: Thu Apr 24, 2008 2:56 pm
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Hi all,

From one of Enrico's replies..,
Quote:
usually PS datasets are not updated, they are created every time,
so the creation date should be the equal to the changed date

From 3.4 list and couple of PF11 strokes..,

I see Created, Referred dates can be diiferent for PS datasets.
And Changed data is not there for PS !?.

Members of PDS will have Created as well as Changed date.

Could anyone please explain in detail?
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enrico-sorichetti

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PostPosted: Thu Apr 24, 2008 3:03 pm
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created means just that
referenced ... opened, irrelevant of mode

the info for the pds members is internally managed by ispf
and stored in the userd data of the directory record
if I remember correctly hitachi ispf like product statistics were different
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expat

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Joined: 14 Mar 2007
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PostPosted: Thu Apr 24, 2008 6:36 pm
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To find the last time that a PS dataset may have been updated is to use SMF type 15 records. These are generated when a dataset is opened for output.
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Anuj Dhawan

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Joined: 22 Apr 2006
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PostPosted: Fri Apr 25, 2008 4:45 am
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Hi,
gnanas wrote:
Created, Referred dates can be diiferent for PS datasets.
Created date is the date when DSN was allocated, got an entry in ccatalog. Reference date is when it was last modified.

For an experiment, pick a file allocated by you, check for it's reference date; now edit it & check for reference date. In later case reference-date should be 'today's date'.
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dick scherrer

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Joined: 23 Nov 2006
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PostPosted: Fri Apr 25, 2008 5:11 am
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Hello,

Accessing a dataset also often updates the reference date.
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Anuj Dhawan

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PostPosted: Fri Apr 25, 2008 5:22 am
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dick scherrer wrote:
Accessing a dataset also often updates the reference date.
Should I say it can be site specific, I tried it at my shop but it doesn't make any difference..?
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dick scherrer

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PostPosted: Fri Apr 25, 2008 6:09 am
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Hi Anuj,

Quote:
Should I say it can be site specific, I tried it at my shop but it doesn't make any difference..?
If you update the file, the reference data changes (at least on every system where i've actually noticed). If you access the file (as in retrieving the "I" info from 3.4), the reference data may be changed - this has not always been consistent.

I'm sure there is some rule, but i've never gone looking to find the specifics. My only caution is that the reference date may not indicate the last time the dataset was actually referenced.
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Gnanas N

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PostPosted: Fri Apr 25, 2008 9:14 pm
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What Anuj has said is that I am trying to say...

But, still I am not clear with this...
Quote:
From one of Enrico's replies..,
Quote:
usually PS datasets are not updated, they are created every time,
so the creation date should be the equal to the changed date
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dick scherrer

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PostPosted: Fri Apr 25, 2008 9:52 pm
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Hello,

Typically, PS datasets are deleted and re-allocated in a job rather than being "written over". One reason is that writing over a qsam file may waste space (if the "new" data is significantly less than the existing data) or the job may abend due to the "new" data requiring more space that is allocated.

Database, vsam, and partioned datasets are typically updated rather than re-created.

If i've mis-understood the question, please clarify.
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Gnanas N

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PostPosted: Mon Apr 28, 2008 2:10 pm
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Thanks Dick for your reply.
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dick scherrer

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PostPosted: Mon Apr 28, 2008 10:12 pm
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You're welcome icon_smile.gif

d
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