CREATE TABLE IF NOT EXISTS device_events ( id VARCHAR(255) PRIMARY KEY, device_id VARCHAR(255) NOT NULL, type VARCHAR(50) NOT NULL, severity VARCHAR(20) NOT NULL, message TEXT, data JSONB, timestamp TIMESTAMP DEFAULT CURRENT_TIMESTAMP, acked BOOLEAN DEFAULT FALSE, acked_by VARCHAR(255), acked_at TIMESTAMP, FOREIGN KEY (device_id) REFERENCES devices(id) ON DELETE CASCADE ); CREATE INDEX idx_device_events_device_id ON device_events(device_id); CREATE INDEX idx_device_events_type ON device_events(type); CREATE INDEX idx_device_events_severity ON device_events(severity); CREATE INDEX idx_device_events_timestamp ON device_events(timestamp); CREATE INDEX idx_device_events_acked ON device_events(acked);