def gen_sites():
    db = Database(util.get_db_root(), util.get_part())
    grid = db.grid()
    for tile_name in sorted(grid.tiles()):
        loc = grid.loc_of_tilename(tile_name)
        gridinfo = grid.gridinfo_at_loc(loc)

        for site, site_type in gridinfo.sites.items():
            if site_type in ['SLICEM']:
                yield site