I agree, we use a UDC at all our customer sites to maintain or XL's. We
leave XL.PUB as a link pointing to an XL named XL000001 and keep
incrementing. We can always roll them back if necessary. Works extremely
well. When we tried it with SL's it caused very odd and unpredictable results.

-Pete

At 10:16 AM 9/6/00 -0700, Duane Percox wrote:
>You may not be familiar with the PURGELINK
>command. It is a handy command that can be
>used to remove files that are in-use and replace
>them with an updated copy of the file. In the
>past this was not always possible since MPE
>wouldn't let you PURGE a file being accessed.
>
>However, the existing users of the file you have
>PURGELINK'ed continue to use the old version and
>any new users will use the new/updated version.
>Once the last user of the old version closes the
>file it is removed.
>
>Typical operation is:
>
>:PURGELINK oldfile
>:COPY newfile,oldfile
>
>You can also use RENAME in place of COPY.
>
> >From our experience we have successfully used this
>to accomplish the following:
>
>* Install a new version of a NM/CM program while it is
>   being used by one or more users.
>
>* Install a new version of a NM library (XL) while it
>   is being used by one or more users.
>
>* Update a UDC file while it is locked (being used by
>   one or more users).
>
>* Install a new version of a file (like a vplus file) while
>   it being used).
>
>*Warning*
>   We have had NO success using PURGELINK with SL files. In
>   fact we have had system hangs as a result.
>
>
>Duane Percox    wk: 650.372.0200x608  fax: 650.372.3386
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