Syntax options:

    WORKLOAD COLLECTION IS ENABLED | WORKLOAD COLLECTION IS DISABLED

    Specifies whether or not the optimizer records workload
    information in the system table RDB$WORKLOAD. The WORKLOAD
    COLLECTION IS ENABLED clause creates this system table if
    it does not exist. If you later disable workload collection,
    the RDB$WORKLOAD system table is not deleted, nor is the data
    deleted.

    A workload profile is a description of the interesting table
    and column references used by queries in a database work load.
    When workload collection is enabled, the optimizer collects
    and records these references in the RDB$WORKLOAD system table.
    This work load is then processed by the RMU Collect Optimizer-
    Statistics command which records useful statistics about the work
    load. These workload statistics are used by the optimizer at run
    time to deliver more accurate access strategies.

    Workload collection is disabled by default.