#define MAX_HOUSES 500
new Iterator:Houses<MAX_HOUSES>;

forward LoadHouses();
public LoadHouses()
{
    new i, domid;
    for(i = 0; i < cache_num_rows(); i++)
    {
                cache_get_value_int(i, "id", Dom[domid][id]);
                cache_get_value(i, "owner", Dom[domid][owner]);
                cache_get_value... itd

                Iter_Add(Houses, domid);
         }
}

CMD:domtp(playerid)
{
    new domekid = Iter_Random(Houses);
    SetPlayerPos(playerid, Dom[domekid ][pos_x],Dom[domekid ][pos_y],Dom[domekid ][pos_z]);
    return 1;
}