Something

 create table event_parameters (
    id INTEGER DEFAULT nextval('opennmsNxtId') NOT NULL,
    eventId INTEGER NOT NULL,
    order INTEGER NOT NULL,
    name text(31)  NOT NULL,
    value text(255)  NOT NULL,
    type varchar(31)  NOT NULL,
    encoding varchar(31)  NOT NULL,

    CONSTRAINT event_parameters_id PRIMARY KEY (id),
    CONSTRAINT event_parameters_eventid FOREIGN KEY (eventid) REFERENCES events (eventid) ON DELETE CASCADE
)

CREATE UNIQUE INDEX event_parameters_eventid_name on event_parameters (eventid, name);
CREATE UNIQUE INDEX event_parameters_eventid_order on event_parameters (eventid, order);
CREATE INDEX  event_parameters_eventid on event_parameters (eventid);
CREATE INDEX  event_parameters_value on event_parameters (value);