Buffers=rollforward-buffer-count

    Specifies the number of database buffers available to roll after-
    image journals forward to the standby database.

    Applicable to:   Standby
                     database
    Required or      Optional
    Optional:

                     Local          Global Buffers
                     Buffers
    Default Value:   4096           4096 or Global Buffer USER LIMIT,
                                    whichever is smaller
    Minimum Value:   2              2
    Maximum Value:   1,048,576      1048576 or Gloal Buffer USER
                                    LIMIT,
                                    whichever is smaller

    During replication operations, the LRS process on the standby
    node receives after-image journal records from the master
    database and rolls them forward to the standby database.

    You can use the optional Buffers qualifier to override the
    default number of database buffers.

    For optimal performance, you should allocate a sufficient number
    of buffers so that the server process can roll the after-image
    journal records forward with a minimum number of I/O operations.
    To estimate an appropriate number of buffers, use the following
    equation as a starting point:

    (Number of Modified Buffers per Transaction * Number of Users) + 20%

    For example, if the average number of modified buffers per
    transaction is 10 and there are 100 users on the database, then
    the server process needs 1000 buffers at one time. To ensure that
    you have an adequate number of buffers, add another 20 percent
    (200 buffers) for a total of 1200 buffers.

    The number of buffers can impact the time it takes for the LRS
    process to checkpoint. When a checkpoint occurs, the LRS must
    write all modified buffers to disk. For example, if the LRS
    is using 2000 buffers, and it takes one second for 2000 disk
    writes to complete, the LRS will be stalled for one second while
    those writes are being done. This could cause the Hot Standby
    governor to increase the synchronization mode if there is a lot
    of update activity occurring while the LRS is checkpointing. For
    some applications this could impose a practical limitation in the
    number of buffers allocated to the LRS.

                                   NOTE

       The LRS process on the standby database does not use buffer
       values defined by the following:

       o  DBM$BIND_BUFFERS logical name

       o  RDB_BIND_BUFFERS configuration parameter

       o  RDM$BIND_BUFFERS logical name

    When replication operations are active, you can use the RMU or
    DBO Show Users command to see the current number of database
    buffers allocated. If replication operations are not active or
    if you want to see the buffer value that was set on a previous
    Replicate After_Journal Start command (stored in the database
    root file), you can also use the Header and Dump_Select_Type=Hot_
    Standby qualifiers on the RMU or DBO Dump command.