where can i find ???

Im new here and i want to know more about postgres

where can i find information about postgres design limits
specifically
                    1) Max number of clients connected in one server
                    2) Maximum Database size
                    3) Maximum number of files per database
                    4) Maximum number of database open in one transaction
                    5) Maximum number of tables per database
                    6) Maximum row size
                    7) Maximum number of rows and columns per table


thanks in advance


ian