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7 Replies Latest reply: Feb 21, 2012 2:10 PM by Iordan Iotzov RSS

Oracle Downstream functionality across different Oracle Versions

pawankella Newbie
Currently Being Moderated
Hi,

I need expert opinion whether we can configure Oracle Downstream in the following environment:

Source Database: 10g R2
Downstream Database: 11g (either R1 or R2)

I have followed document 753158.1 and successfully configured Oracle Downstream between 2 10g R2 databases but have no idea whether it is possible or not in the above mentioned environment.

Waiting for the prompt responses with concrete references.


Thanks & Regards,
  • 1. Re: Oracle Downstream functionality across different Oracle Versions
    pmcelroy Newbie
    Currently Being Moderated
    Yes. You can configure a downstream capture using 11g downstream capture database and processing logfiles from a 10gR2 source database.

    Here is the list of operational requirements for downstream capture from the 11.2 Oracle Streams Concepts and Administration manual
    http://download.oracle.com/docs/cd/E11882_01/server.112/e17069/ap_restrictions.htm#CIHDIHFD

    Operational Requirements for Downstream Capture
    The following are operational requirements for using downstream capture:

    The source database must be running at least Oracle Database 10g and the downstream capture database must be running the same release of Oracle Database as the source database or later.

    The downstream database must be running Oracle Database 10g Release 2 or later to configure real-time downstream capture. In this case, the source database must be running Oracle Database 10g Release 1 or later.

    The operating system on the source and downstream capture sites must be the same, but the operating system release does not need to be the same. In addition, the downstream sites can use a different directory structure than the source site.

    The hardware architecture on the source and downstream capture sites must be the same. For example, a downstream capture configuration with a source database on a 32-bit Sun system must have a downstream database that is configured on a 32-bit Sun system. Other hardware elements, such as the number of CPUs, memory size, and storage configuration, can be different between the source and downstream sites.
  • 2. Re: Oracle Downstream functionality across different Oracle Versions
    pawankella Newbie
    Currently Being Moderated
    Hi Pmcelro,

    Thanks for your reply. But I am confused that how 10g archives will be able to apply on 11g? Yes, sure source and destination must be on 10gR1 or later but it is not mentioned in any Oracle document that we can go with downstream implementation on mixture of 10g and 11g configuration. There is a document 752871.1 which states:

    "Streams can be used across different hardware, different OS & different Oracle Versions."

    But again it is about Oracle Streams not for Downstream scenario.


    I hope my scenario must be cleared now.


    Thanks & Regards.
  • 3. Re: Oracle Downstream functionality across different Oracle Versions
    pmcelroy Newbie
    Currently Being Moderated
    The link and the Operational Requirements information in my original reply come from the Oracle Streams documentation set for Oracle Database 11g Release 11.2 Appendix B "Oracle Streams Restrictions". The referenced Operational Requirements section is specific to the Oracle Streams downstream capture feature.

    Using your example configuration, downstream capture on the 11g database in combination with the Streams Apply on the 11g database can apply changes from the source 10g database assuming that both databases are on the same platform type. Use the same queue name for both the downstream capture and apply queue configuration.

    Edited by: pmcelroy on Feb 18, 2011 11:50 AM
  • 4. Re: Oracle Downstream functionality across different Oracle Versions
    917612 Newbie
    Currently Being Moderated
    Hi,

    i would like to have oracle streams in the following environment:

    - Source Database Oracle 11gR2 (capture)
    - Destination Database 10gR2 (apply)

    is it possbile to that configuration ?

    thanks for your help
  • 5. Re: Oracle Downstream functionality across different Oracle Versions
    Jocelyn Simard Explorer
    Currently Being Moderated
    Yes it works...

    But, the COMPATIBLE database parameter of the source database must be <= to the destination database.

    And COMPATIBLE can't be lower down.

    So, if your source database has COMPATIBLE = 11.2.0.3, then you will have to recreate your database!

    If your 11g source database has compatible = 10.2 then you'll be fine...

    Regards,
    Jocelyn
  • 6. Re: Oracle Downstream functionality across different Oracle Versions
    pmcelroy Newbie
    Currently Being Moderated
    Streams can interoperate between an 11.2 source and 10.2 destination. There is no requirement that the COMPATIBLE of the source database be <= to the destination database.

    However, 11.2 can capture more data types than 10.2 can handle - so you need to manage the rules to restrict the 11.2 source to capture only changes that can be applied by 10.2.
    You can do this with the rules using the function lcr$_row_record.get_compatible(). If you use the dbms_streams_adm package ADD_TABLE_RULES procedure, you can specify this condition as
    AND_CONDITION=>':lcr.GET_COMPATIBLE() <= DBMS_STREAMS.COMPATIBLE_10_2()'

    This AND_CONDITION will add a check to make sure that only changes compatible with Oracle database release 10.2 or below are processed by Streams. The compatibility check only needs to happen on the capture rules.
  • 7. Re: Oracle Downstream functionality across different Oracle Versions
    Iordan Iotzov Expert
    Currently Being Moderated
    I believe the discussion was about downstream capture…

    This MOS document can be helpful:
    ---------------------------------------------------------------------------------------------------------------------------------------
    Error Registering A Logfile In Logminer By Redo Transport Service: "LogMiner: Error 331 encountered, failed to read corrupt logfile" [ID 1114095.1]
    ---------------------------------------------------------------------------------------------------------------------------------------

    Iordan Iotzov
    http://iiotzov.wordpress.com/

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