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  • 1.  dbimport to the older Informix

    Posted Wed November 16, 2022 04:52 AM
    We have a task to move from Informix 9 to Informix 14. We tested our program on Informix 14 and so far everything looks fine. We will change the production version soon.
    So while we decide what to do if something goes wrong. Of course, we don't want to lose data.
    Will there be any problems if after some time we decide to go back to Informix 9 and run dbexport on Informix 14 and dbimport on Informix 9?

    Alexander Ivanov


  • 2.  RE: dbimport to the older Informix

    Posted Wed November 16, 2022 05:46 AM
    not sure if it works back to version 9.x but onmode -b is meant to revert internal structures
    in order to be able to startup database with older version without a restore.
    That way, the old binaries might be able to boot the database when it has been converted to 14.x.
    (maybe you will need to regenerate the update statistics (as recommended after an upgrade).

    You can try this on a converted instance of 9.x to 14.10.
    For examples of the onmode -b command, see Syntax of the onmode -b command.. When you revert to the older version, Informix displays messages that tell you when reversion begins and ends. When the reversion is complete, Informix is offline. The reversion utility drops the Informix Version 14.10 system catalog tables and restores compatibility so that you can access the data with the earlier ...

    Otherwise, dbimport should work, dbexport should be done with -ss flag in order to get 
    the same table sizes.
    When you want to double check it: Try to generate the table structure (using dbschema from the existing 9.x instance),
    make a test DB in new 14.x instance, load the schema with dbaccess and then dbexport -ss and dbimport the test DB 
    in 9.x instance, just to make sure the syntax has not changed.



  • 3.  RE: dbimport to the older Informix

    IBM Champion
    Posted Wed November 16, 2022 06:44 AM

    I agree with Marcus. That should work as long as you have not added any v14 specific features to the database(s) that v9 does not support after creating the new databases. As far as verifying that it will not be a problem, you can just use dbschema -ss against both copies of the database for this or my myschema utility as well and compare the outputs. If the schema outputs are identical except for trivialities like EXTENT and NEXT clauses etc., then you are good to go. The data itself is completely compatible.


    Art S. Kagel, President and Principal Consultant
    ASK Database Management Corp.