Master_Root=master-rootfile

    Identifies the name of the master database root file from
    which the replication servers on the standby database receive
    replication data.

    Applicable to:     Standby database
    Required or        Required the first time you enter the
    Optional:          Replicate After_Journal Start command and
                       any time you specify other Replication
                       Startup qualifiers. Optional on all subsequent
                       invocations.
    Default Value:     None.

    You must include the Master_Root qualifier the first time you
    enter the Replicate After_Journal Start command (unless you have
    preconfigured the Master_Root qualifier using the Replication
    After_Journal Configure command). This ensures that the standby
    database uses the master database you specify as the source of
    the replication operations. If you omit the Master_Root qualifier
    on subsequent Replicate After_Journal Start commands, the Hot
    Standby software retrieves the master database name from the
    header information in the database root file.

    Whenever you specify the Master_Root qualifier, you must do the
    following to ensure the command executes successfully:

    o  Specify the name of the master database root file.

       Do not specify the name of the standby database on the Master_
       Root qualifier. Any attempt to use a restored database as a
       master database causes replication startup operations to fail.

    o  Include a node name and directory path for remote network
       communications.

       You can define a logical name to identify the master node.

    o  Be able to access the master database.

       When the master database node is configured in a VMScluster
       system, the node name you specify with the Master_Root
       qualifier can be any participating node from which the master
       database can be accessed. Cluster aliases are acceptable when
       you use the Master_Root qualifier.

    The master and standby databases communicate using network
    communications (for remote database access) or interprocess
    communications (for local database access) according to how you
    specify the master database name. The following table describes
    how the Hot Standby software chooses the method of communication:

    If . . .               Then . . .

    You include a node     The Hot Standby software uses remote
    name when you specify  network communications to receive the
    the master database    after-image journal log changes, unless
    root file              the specified node is the current node

    You do not include     The Hot Standby software uses local
    a node name when you   interprocess communications to receive
    specify the master     the after-image journal log changes
    database root file

    The Hot Standby software compares and verifies the master
    database (that you specify with the Master_Root qualifier)
    against the standby database (that you specify with the Standby_
    Root qualifier when you start replication operations on the
    master database). This verification ensures that both databases
    are identical transactionally.