Syntax option:

    USER LIMIT IS max-glo-buffers

    Specifies the maximum number of global buffers each attach
    allocates. Because global buffer pools are shared by all
    attachments, you must define an upper limit on how many global
    buffers a single attach can allocate. This limit prevents a user
    from defining the RDM$BIND_BUFFERS logical name to use all the
    buffers in the global buffer pool. (The behavior of RDM$BIND_
    BUFFERS which depends on whether you are using local or global
    buffers, is explained in the Oracle Rdb7 Guide to Database
    Performance and Tuning.)

    The user limit cannot be greater than the total number of global
    buffers. The default is 5 buffers. The user limit appears as
    "maximum global buffer count per user" in RMU Dump command
    output.

    Decide the maximum number of global buffers a process can
    allocate per attach by dividing the total number of global
    buffers set by the NUMBER IS clause by the total number of
    attachments for which you want to guarantee access to the
    database. For example, if the total number of global buffers is
    200 and you want to guarantee at least 10 attachments access to
    the database, set the maximum number of global buffers per attach
    to 20.

    In general, when you use global buffers, you should set the
    maximum global buffer count per user higher than the default
    database buffer count. For maximum performance on a VMScluster
    system, tune the two global buffer parameters on each node in
    the cluster using the RMU Open command with the Global_Buffers
    qualifier.

    Although you can change the USER LIMIT IS parameter on line, the
    change does not take effect until the next time the database is
    opened.

    The NUMBER IS and USER LIMIT IS parameters are the only two
    buffer parameters specific to global buffers. They are,
    therefore, in effect on a per node rather than a per process
    basis.