License-exempt operation is considered to be a promising solution for spectrum-resource scarcity. Incumbent protection and coexistence management constitute two fundamental aspects of the successful operation. Under regulations for TV white space (TVWS), WS devices (WSDs) are required to access a WS database (WSDB) every time their individual location changes by >50 m. If the aggregate-interference effect is considered, one WSD's location change can incur frequent adjustment of the available spectrum for other WSDs. In this article, we present a practical low-complexity WSDB-assisted TVWS operation complying with the current regulatory progress in Europe. First, we propose a new procedure of setting emission limits for WSDs. By modeling the WSD distribution as the Poisson point process (PPP), we obtain a percentage emission limit valid for a WSD mobility region. By using the proposed procedure with the percentage emission limit in an example scenario, we reduce the complexity by 90% compared to the exiting procedure. Second, we present a succinct scheme to achieve the efficient coexistence of WSDs by deducing an upper bound on the number of cochannel WSDs over a given region.