Re: Easy DCL question PURGE vs. DELETE - VMS

This is a discussion on Re: Easy DCL question PURGE vs. DELETE - VMS ; Doug Phillips wrote on 08/06/2007 08:21:36 PM: > On Aug 6, 3:48 pm, AEF wrote: > > On Aug 6, 1:27 pm, Doug Phillips wrote: > > > On Aug 5, 7:17 pm, AEF wrote: > > > > On ...

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Thread: Re: Easy DCL question PURGE vs. DELETE

  1. Re: Easy DCL question PURGE vs. DELETE




    Doug Phillips wrote on 08/06/2007 08:21:36 PM:

    > On Aug 6, 3:48 pm, AEF wrote:
    > > On Aug 6, 1:27 pm, Doug Phillips wrote:
    > > > On Aug 5, 7:17 pm, AEF wrote:
    > > > > On Aug 5, 4:26 pm, Doug Phillips wrote:
    > > > > > On Aug 5, 2:10 pm, AEF wrote:
    > > > > > > On Aug 5, 2:20 pm, Doug Phillips wrote:

    [8< SNIP >8]
    >
    > P.S. to Norm: I thought you said "Easy DCL question...":-)
    >

    Yes, I did, but my instincts were correct that I was missing something.
    I just didn't realize how confusing the something is. I am still not
    clear as to what is current behavior - I'll have to do a careful reread of
    the latter posts.

    In my case, I can live with all versions being deleted if before my
    date_time,
    even if no version is retained, so I have switched from a purge/before to a
    delete/before.

    I'd say it will take more that a page to properly document what actually
    happens in the newer revisions and *that* should be done as a priority.

    -Norm

    --------------------
    "Everything worthwhile eventually degenerates into real work." -Murphy


  2. Re: Easy DCL question PURGE vs. DELETE

    On Aug 7, 8:38 am, norm.raph...@metso.com wrote:
    > Doug Phillips wrote on 08/06/2007 08:21:36 PM:
    >
    > > On Aug 6, 3:48 pm, AEF wrote:
    > > > On Aug 6, 1:27 pm, Doug Phillips wrote:
    > > > > On Aug 5, 7:17 pm, AEF wrote:
    > > > > > On Aug 5, 4:26 pm, Doug Phillips wrote:
    > > > > > > On Aug 5, 2:10 pm, AEF wrote:
    > > > > > > > On Aug 5, 2:20 pm, Doug Phillips wrote:

    > [8< SNIP >8]
    >
    > > P.S. to Norm: I thought you said "Easy DCL question...":-)

    >
    > Yes, I did, but my instincts were correct that I was missing something.
    > I just didn't realize how confusing the something is. I am still not
    > clear as to what is current behavior - I'll have to do a careful reread of
    > the latter posts.


    The command

    $ PURGE/BEFORE=time/KEEP=1

    is the same

    $ DELETE/BEFORE=time/EXCLUDE=;

    if it were a valid command and changing 1 to n would keep n-1 more of
    the highest versions that would be deleted if it were still 1.

    > In my case, I can live with all versions being deleted if before my
    > date_time,
    > even if no version is retained, so I have switched from a purge/before to a
    > delete/before.
    >
    > I'd say it will take more that a page to properly document what actually
    > happens in the newer revisions and *that* should be done as a priority.


    Actually, it's not *that* bad.

    Here's from the doc:

    *** The PURGE command deletes earlier versions of files. ***

    [OK, this means that PURGE deletes *EARLIER* (non-current) versions of
    files.]

    *** BEFORE[=time]
    Selects only those files dated prior to the specified time. You can
    specify time as absolute time, as a combination of absolute and delta
    times, or as one of the following keywords: BOOT, LOGIN, TODAY
    (default), TOMORROW, or YESTERDAY. Specify one of the following
    qualifiers with the /BEFORE qualifier to indicate the time attribute
    to be used as the basis for selection: /BACKUP, /CREATED (default), /
    EXPIRED, or /MODIFIED. ***

    [OK, this tells you *which* of the earlier files to delete. It's
    simple: PURGE deletes earlier [non-current] versions of files and /
    BEFORE narrows down which of those earlier [non-current] versions to
    delete!]

    /KEEP=number-of-versions
    Specifies the maximum number of versions of the specified files to be
    retained in the directory. If you do not include the /KEEP qualifier,
    all but the highest numbered version of the specified files are
    deleted from the directory.

    [OK, this needs some serious improvement. I find it ambiguous even
    when other qualifiers are not specified at all. I'd say /KEEP=1 means
    keep the current version of each file and /KEEP=n keeps n-1 of the
    highest versions of the files subject to deletion.]

    > -Norm
    >
    > --------------------
    > "Everything worthwhile eventually degenerates into real work." -Murphy


    AEF


  3. Re: Easy DCL question PURGE vs. DELETE

    On Aug 7, 9:34 am, AEF wrote:
    > On Aug 7, 8:38 am, norm.raph...@metso.com wrote:
    >
    > > Doug Phillips wrote on 08/06/2007 08:21:36 PM:

    >
    > > > On Aug 6, 3:48 pm, AEF wrote:
    > > > > On Aug 6, 1:27 pm, Doug Phillips wrote:
    > > > > > On Aug 5, 7:17 pm, AEF wrote:
    > > > > > > On Aug 5, 4:26 pm, Doug Phillips wrote:
    > > > > > > > On Aug 5, 2:10 pm, AEF wrote:
    > > > > > > > > On Aug 5, 2:20 pm, Doug Phillips wrote:

    > > [8< SNIP >8]

    >
    > > > P.S. to Norm: I thought you said "Easy DCL question...":-)

    >
    > > Yes, I did, but my instincts were correct that I was missing something.
    > > I just didn't realize how confusing the something is. I am still not
    > > clear as to what is current behavior - I'll have to do a careful reread of
    > > the latter posts.

    >
    > The command
    >
    > $ PURGE/BEFORE=time/KEEP=1
    >
    > is the same
    >
    > $ DELETE/BEFORE=time/EXCLUDE=;
    >
    > if it were a valid command and changing 1 to n would keep n-1 more of
    > the highest versions that would be deleted if it were still 1.


    Uh, make that

    if it were a valid command and changing 1 to n would additionally keep
    the n-1 highest versions of those that would be deleted if it were
    still 1.

    [...]

    > Here's from the doc:
    >
    > *** The PURGE command deletes earlier versions of files. ***
    >
    > [OK, this means that PURGE deletes *EARLIER* (non-current) versions of
    > files.]
    >
    > *** BEFORE[=time]
    > Selects only those files dated prior to the specified time. You can
    > specify time as absolute time, as a combination of absolute and delta
    > times, or as one of the following keywords: BOOT, LOGIN, TODAY
    > (default), TOMORROW, or YESTERDAY. Specify one of the following
    > qualifiers with the /BEFORE qualifier to indicate the time attribute
    > to be used as the basis for selection: /BACKUP, /CREATED (default), /
    > EXPIRED, or /MODIFIED. ***
    >
    > [OK, this tells you *which* of the earlier files to delete. It's
    > simple: PURGE deletes earlier [non-current] versions of files and /
    > BEFORE narrows down which of those earlier [non-current] versions to
    > delete!]
    >
    > /KEEP=number-of-versions
    > Specifies the maximum number of versions of the specified files to be
    > retained in the directory. If you do not include the /KEEP qualifier,
    > all but the highest numbered version of the specified files are
    > deleted from the directory.
    >
    > [OK, this needs some serious improvement. I find it ambiguous even
    > when other qualifiers are not specified at all. I'd say /KEEP=1 means
    > keep the current version of each file and /KEEP=n keeps n-1 of the
    > highest versions of the files subject to deletion.]


    Uh, make that

    [OK, this needs some serious improvement. I find it ambiguous even
    when other qualifiers are not specified at all. I'd say /KEEP=1 means
    keep the current version of each file and /KEEP=n means keep the
    current version and the n-1 highest versions of the files subject to
    deletion.]

    > > -Norm

    >
    > > --------------------
    > > "Everything worthwhile eventually degenerates into real work." -Murphy

    >
    > AEF


    I apologize for not catching these before posting.

    AEF


  4. Re: Easy DCL question PURGE vs. DELETE

    On Aug 7, 8:51 am, AEF wrote:
    > On Aug 7, 9:34 am, AEF wrote:
    > > On Aug 7, 8:38 am, norm.raph...@metso.com wrote:
    > > > Doug Phillips wrote on 08/06/2007 08:21:36 PM:
    > > > > On Aug 6, 3:48 pm, AEF wrote:
    > > > > > On Aug 6, 1:27 pm, Doug Phillips wrote:
    > > > > > > On Aug 5, 7:17 pm, AEF wrote:
    > > > > > > > On Aug 5, 4:26 pm, Doug Phillips wrote:
    > > > > > > > > On Aug 5, 2:10 pm, AEF wrote:
    > > > > > > > > > On Aug 5, 2:20 pm, Doug Phillips wrote:
    > > > [8< SNIP >8]

    >
    > > > > P.S. to Norm: I thought you said "Easy DCL question...":-)

    >
    > > > Yes, I did, but my instincts were correct that I was missing something.
    > > > I just didn't realize how confusing the something is. I am still not
    > > > clear as to what is current behavior - I'll have to do a careful reread of
    > > > the latter posts.

    >
    > > The command

    >
    > > $ PURGE/BEFORE=time/KEEP=1

    >
    > > is the same

    >
    > > $ DELETE/BEFORE=time/EXCLUDE=;

    >
    > > if it were a valid command and changing 1 to n would keep n-1 more of
    > > the highest versions that would be deleted if it were still 1.

    >
    > Uh, make that
    >
    > if it were a valid command and changing 1 to n would additionally keep
    > the n-1 highest versions of those that would be deleted if it were
    > still 1.
    >
    > [...]
    >
    >
    >
    > > Here's from the doc:

    >
    > > *** The PURGE command deletes earlier versions of files. ***

    >
    > > [OK, this means that PURGE deletes *EARLIER* (non-current) versions of
    > > files.]

    >


    The HELP I have and the current (83final) and older docs (that I've
    looked at) says:

    "Deletes all but the highest numbered versions of the specified
    files."

    note: *specified files*


    That goes back to our confusing discussion about "what is a specified
    file." You read it as only the "filename.ext" (plus node::dev:[dir] of
    course), but I read it as "all files selected by the parameters and
    qualifiers in this command."

    Changing it to read "Preserves the highest version of the files
    specified by the filespec parameter and command qualifiers.

    Might be clearer.


    > > *** BEFORE[=time]
    > > Selects only those files dated prior to the specified time. You can
    > > specify time as absolute time, as a combination of absolute and delta
    > > times, or as one of the following keywords: BOOT, LOGIN, TODAY
    > > (default), TOMORROW, or YESTERDAY. Specify one of the following
    > > qualifiers with the /BEFORE qualifier to indicate the time attribute
    > > to be used as the basis for selection: /BACKUP, /CREATED (default), /
    > > EXPIRED, or /MODIFIED. ***

    >



    There again, "selects only those files dated prior to the specified
    time" would lead one to expect that files *not* "dated prior to the
    specified time" would *not* be selected.

    Changing it to: "selectes only the filespec's lower versions that are
    dated prior to the specified time"

    would be closer to the way it works now.

    > > [OK, this tells you *which* of the earlier files to delete. It's
    > > simple: PURGE deletes earlier [non-current] versions of files and /
    > > BEFORE narrows down which of those earlier [non-current] versions to
    > > delete!]

    >
    > > /KEEP=number-of-versions
    > > Specifies the maximum number of versions of the specified files to be
    > > retained in the directory. If you do not include the /KEEP qualifier,
    > > all but the highest numbered version of the specified files are
    > > deleted from the directory.

    >
    > > [OK, this needs some serious improvement. I find it ambiguous even
    > > when other qualifiers are not specified at all. I'd say /KEEP=1 means
    > > keep the current version of each file and /KEEP=n keeps n-1 of the
    > > highest versions of the files subject to deletion.]

    >
    > Uh, make that
    >
    > [OK, this needs some serious improvement. I find it ambiguous even
    > when other qualifiers are not specified at all. I'd say /KEEP=1 means
    > keep the current version of each file and /KEEP=n means keep the
    > current version and the n-1 highest versions of the files subject to
    > deletion.]
    >
    > > deleted from the directory.



    The docs & help are absolutely ambiguous for the way the purge works
    now. But, I think n-1 would be too confusing. I can't think of a
    concise way to explain how it works without using an example, but
    maybe something like:

    "Specifies the maximum number of versions of the selected files
    including the highest numbered filespec version that should be
    retained in the directory.
    If you do not specify the /KEEP qualifier the default of /KEEP=1
    will be used, only the highest numbered version of the filespec file
    will be retained and all qualified lower versions will be deleted."

    Nope. I don't like it. That could be improved but I think it's closer
    than what the doc says now. (I don't have a problem with maximum,
    except as to how it is inclusive of the highest version and qualified
    version.)

    I've tried to remain in the context of "help" rather than the docs,
    and the doc's should certainly explain it in more depth and with
    sufficient examples so that all ambiguity is removed.



  5. Re: Easy DCL question PURGE vs. DELETE

    [bad doug, replied to self]

    On Aug 7, 1:24 pm, Doug Phillips wrote:
    > On Aug 7, 8:51 am, AEF wrote:
    >
    >
    >
    > > On Aug 7, 9:34 am, AEF wrote:
    > > > On Aug 7, 8:38 am, norm.raph...@metso.com wrote:
    > > > > Doug Phillips wrote on 08/06/2007 08:21:36 PM:
    > > > > > On Aug 6, 3:48 pm, AEF wrote:
    > > > > > > On Aug 6, 1:27 pm, Doug Phillips wrote:
    > > > > > > > On Aug 5, 7:17 pm, AEF wrote:
    > > > > > > > > On Aug 5, 4:26 pm, Doug Phillips wrote:
    > > > > > > > > > On Aug 5, 2:10 pm, AEF wrote:
    > > > > > > > > > > On Aug 5, 2:20 pm, Doug Phillips wrote:

    [snip]
    >
    > The HELP I have and the current (83final) and older docs (that I've
    > looked at) says:
    >
    > "Deletes all but the highest numbered versions of the specified
    > files."
    >

    [...]
    >
    > Changing it to read "Preserves the highest version of the files
    > specified by the filespec parameter and command qualifiers."


    Needs to say something about delete:

    "Preserves the highest version of the files specified by the filespec
    parameter and command qualifiers and deletes all lower version of the
    specified files."

    is better, but still has room for improvement.


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