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Conference vmszoo::rms_openvms

Title:RMS asks, 'R U Journaled?'
Moderator:STAR::TSPEERUVEL
Created:Tue Mar 11 1986
Last Modified:Wed Jun 04 1997
Last Successful Update:Fri Jun 06 1997
Number of topics:3031
Total number of notes:12302

3010.0. "journal file format available ???" by XFMV01::AJITK () Mon Feb 10 1997 01:25

Hi 

A customer wants to propagate the updates of RMS files to 
a database (Oracle). He is inquiring if the RMS jounalling
product can be used for this. This will require a knowledge
of the format of rms journal file. Is this available and
documented ?

Any other suggestions ?

Regards

Ajit Kale
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3010.1STAR::TSPEERMon Feb 10 1997 11:196
I'm not sure what tools or integrators there may be that would
address your problem, but I do know that no application should
reply on the internal format of RMS journal files.  These have
never been documented.

Tom
3010.2Not Without Recoding The Application...XDELTA::HOFFMANSteve, OpenVMS EngineeringMon Feb 10 1997 11:2434
    I'm not entirely certain what you are asking...  I'm assuming that
    the customer is looking to redirect RMS system calls into an Oracle
    database...

    If the customer has access to the application source(s), I would
    update these to use callable SQL or imbedded SQL, and write to the
    database directly.  I know of no way to redirect RMS calls into SQL
    calls, and thus into a database.  (Though that _would_ be a rather
    interesting and sometimes very useful migration tool.)

    Oracle (Rdb) supports its own journal files and journalling support.
    The mechanisms used are the same as those used by RMS -- both are
    based on the DECdtm services.  But both have their own monitor and
    support code, and (very likely) their own unique internal journal
    file formats and journal file processing support.

    As for stuffing an RMS file -- such as a journal file -- into a
    database, one might be able to use the (Rdb) multi-media extensions,
    or -- if this is not Rdb, whatever support the database may have for
    inserting an "object" in the database.  (This support allows one to
    stuff an arbitrary file into a `container' in the database.)  This
    isn't quite what you likely want, obviously...    

    It is possible to combine Rdb and RMS journalling using the DECdtm
    services -- one can have a single transaction across one or more
    RMS files, and across one or more database files.  I do not know
    if non-Rdb databases make use of DECdtm, and can thus be combined
    into `multi-file' transactions in this fashion.  (This requires
    source access.)

    I would recommend against integrating the RMS journal file format
    into a customer application.  (This format is subject to change.)

3010.3EPS::VANDENHEUVELHeinThu Feb 13 1997 05:3815
    
>a database (Oracle). He is inquiring if the RMS jounalling
>product can be used for this. 
    
    I concur with the previous replies, but like to add
    contrete answeres to your questions: no, no and no.
    RMS Journallinglogs changed buckets with no indication
    what changed in the bucket. Even if you figured out
    the layout (not too hard), it would do no good as you
    would not know which record changed. You'll need added
    application support, calling a DBI or perhpas adding 
    a (key) field to a file including a change flag/timestamp.
    
    Hein.