set term ^;
create or alter procedure sys_get_fb_arch (
    a_current_user_pswd varchar(31) = 'masterkey'
)
returns (
    fb_arch varchar(2))
as
    declare cur_server_pid int;
    declare ext_server_pid int;
    declare fetches_db0 bigint;
    declare end_fetches1 bigint;
    declare v_dummy_role varchar(31);
begin
    
    -- Aux SP for detect FB architecture. Caller must specify his own password when invoke this SP!
    -- Samples:
    -- 1) For SYSDBA, with suppose that env. variables ISC_USER & ISC_PASSWORD does exist
    -- and ISC_PASSWORD = masterkey, - invoking can be w/o specifying password:
    -- echo set list on; select * from sys_get_fb_arch; | isql /3333:database_alias
    -- 2) For non-privileged user:
    -- SQL> create user u01 password '123';
    -- SQL> grant execute on procedure sys_get_fb_arch to u01;
    -- SQL> exit;
    -- C:\> echo set list on; select * from sys_get_fb_arch('123'); | isql /3333:database_alias -u u01 -pas 123

    select a.mon$server_pid from mon$attachments a
    where a.mon$attachment_id = current_connection
    into cur_server_pid;

    select i.mon$page_fetches
    from mon$io_stats i
    where i.mon$stat_group = 0  -- db_level
    into fetches_db0;

    v_dummy_role = left('R'||replace(uuid_to_char(gen_uuid()),'-',''), 31);

    execute statement 'select a.mon$server_pid + 0*(select count(*) from rdb$types,rdb$types) from mon$attachments a where a.mon$attachment_id = current_connection'
    on external 'localhost:' || rdb$get_context('SYSTEM', 'DB_NAME')
    as
        user current_user
        password a_current_user_pswd
        role :v_dummy_role -- this will force FB to create NEW attachment.
    into ext_server_pid;

    in autonomous transaction do
    select i.mon$page_fetches
    from mon$io_stats i
    where i.mon$stat_group = 0  -- db_level
    into end_fetches1;

    fb_arch = iif( cur_server_pid is distinct from ext_server_pid, 
                   'CS', 
                   iif( fetches_db0 is not distinct from end_fetches1, 
                        'SC', 
                        'SS'
                      ) 
                 );
    suspend;

end
^
set term ;^
commit;