Puis-je faire en sorte que SQL Server appelle une procédure stockée toutes les n secondes ?

Utilisez un minuteur et activation . Aucun processus externe, continue de fonctionner après un basculement de mise en cluster ou de mise en miroir, continue de fonctionner même après une restauration sur une autre machine, et cela fonctionne également sur Express.

-- create a table to store the results of some dummy procedure
create table Activity (
    InvokeTime datetime not null default getdate()
    , data float not null);
go  

-- create a dummy procedure
create procedure createSomeActivity
as
begin
    insert into Activity (data) values (rand());
end
go

-- set up the queue for activation
create queue Timers;
create service Timers on queue Timers ([DEFAULT]);
go

-- the activated procedure
create procedure ActivatedTimers
as
begin
declare @mt sysname, @h uniqueidentifier;
begin transaction;
    receive top (1)
        @mt = message_type_name
        , @h = conversation_handle
        from Timers;

    if @@rowcount = 0
    begin
        commit transaction;
        return;
    end

    if @mt in (N'http://schemas.microsoft.com/SQL/ServiceBroker/Error'
        , N'http://schemas.microsoft.com/SQL/ServiceBroker/EndDialog')
    begin
        end conversation @h;
    end
    else if @mt = N'http://schemas.microsoft.com/SQL/ServiceBroker/DialogTimer'
    begin
        exec createSomeActivity;
        -- set a new timer after 2s
        begin conversation timer (@h) timeout = 2;
    end
commit
end
go

-- attach the activated procedure to the queue
alter queue Timers with activation (
    status = on
    , max_queue_readers = 1
    , execute as owner
    , procedure_name = ActivatedTimers);
go  


-- seed a conversation to start activating every 2s
declare @h uniqueidentifier;
begin dialog conversation @h
    from service [Timers]
    to service N'Timers', N'current database'
    with encryption = off;
begin conversation timer (@h) timeout = 1;

-- wait 15 seconds
waitfor delay '00:00:15';

-- end the conversation, will stop activating
end conversation @h;
go

-- check that the procedure executed
select * from Activity;