VMS Help  —  RMU72  Hot Standby, Replicate After Journal Commands, Start  Command Qualifiers, Governor
    Governor=Enabled
    Governor=Disabled

    Enables or disables the replication governor.

    Applicable to:              Standby database
    Required or Optional:       Optional
    Default Value:              Governor=Enabled

    The purpose of the replication governor is to coordinate database
    replication operations automatically between the master and the
    standby databases. With the replication governor enabled, you can
    effectively ensure that:

    o  The master and standby databases do not get too far out of
       synchronization with respect to each other

    o  The performance of the master database does not deviate
       greatly from that of the standby database

    o  The peak-time database requirements are handled automatically
       and dynamically by the Hot Standby software

    The replication governor allows the ALS process on the master
    database and the LRS process on the standby database to
    automatically choose the synchronization mode that provides
    the best performance and ensures database replication
    synchronization.

    To use the replication governor most effectively, ensure
    the Governor qualifier is Enabled and include the
    Synchronization=Cold qualifier when you start replication
    operations on the standby database. (Also, see the
    Synchronization qualifier discussed later in this Help topic.)

    Oracle Corporation recommends that you set the Synchronization
    qualifier to Cold mode. This setting is most effective because
    of the way the LRS process monitors its replication workload from
    the master database, as described in the following table:

    If . . .               Then . . .

    The replication        The LRS process automatically upgrades
    workload increases at  to a stronger synchronization mode. For
    a rate that prevents   example, if the Synchronization qualifier
    the standby database   was originally set to Cold mode, the LRS
    from keeping up with   would change the synchronization mode to
    the master database    Warm (or higher, as required).

    The replication        The LRS process automatically downgrades
    workload shrinks       or weakens the synchronization mode.
                           However, the synchronization mode is
                           never weaker than the mode (Commit, Hot,
                           Warm, Cold) that you specify with the
                           Synchronization qualifier.

    Because the synchronization mode changes dynamically, the LRS
    process transmits the current synchronization mode to the ALS
    process (on the master database) at every checkpoint interval
    (see the Checkpoint qualifier earlier in this Help topic). For
    example, if the replication governor upgrades the synchronization
    mode from Cold to Warm, the LRS process transmits the information
    to the ALS process. Then, the ALS process uses the stronger mode
    on all subsequent messages to the standby database. (Note that
    the LRS process maintains a different synchronization mode for
    each master database node.)

    Use the RMU Show Statistics command on the master database to
    monitor the dynamically changing synchronization mode required by
    the actual work load, and compare that to the mode you specified
    with the Synchronization qualifier.

    Recommendation: Oracle Corporation recommends that you do not use
    the Governor=Disabled setting until the replication performance
    is well understood and constant. Severe performance deviations on
    the master database could stall or stop the database replication
    operations.
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