Data Integration

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  • 1.  cdc and db2 migration

    Posted Sun July 09, 2023 02:56 AM

    there used to be a group for CDC, but I can not find it anymore

    as I read well, when upgrading db2 as target source, you need to mark all tables for capture point 

    but what todo in this scenario : the target db2 is being migrated. in the meantime, the source db is being used

    after the migration, if marking capture point, you loose all modifs from migration time. so full refresh is needed

    but we have multiple sources going to the same target table and can not do full refresh. so we need differential refresh. as we have large tables and many tables, it will days to do this refresh. is there any scenario that would help us to avoid this refresh.

    we have been thinking to create in the target a table for each source and do the full refresh. after this to merge this table with the consolidated table.

    any idea/info would be helpfull



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    Thanks for all answers
    Best Regards,
    Guy Przytula
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  • 2.  RE: cdc and db2 migration

    Posted Tue August 22, 2023 08:30 AM

    Hello Guy

    If DB2 is the target and some other database is the source, I don't think you need to take any action with mark table capture point, as this is only done on the source.

    What the CDC documentation should be saying, I believe, is that if your DB2 database is the source, you need to do the following:

    1) Stop updating the database

    2) Ensure CDC replication is ended normally so that all outstanding changes are replicated

    3) Do the upgrade

    4) Do mark table capture point

    5) Restart CDC

    6) Resume updating the DB2 database

    Thus there are no changes between the end point of replication and mark capture point, so no data loss.

    Clearly if the target database is upgraded it is not always possible to quiesce the source database so the procedure given for mark table capture point makes no sense for a target database.

    You may still need to perform the other tasks mentioned in https://www.ibm.com/docs/en/idr/11.4.0?topic=credl-considerations-upgrading-your-db2-linux-unix-windows-database (steps 2 and 3)



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    Robert Philo
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    Original Message