declare @n int;

set statistics time on;

print 'AlanDenton'
;WITH
    E1(N) AS (
        SELECT * FROM (
            VALUES
                (1),(1),(1),(1),(1),
                (1),(1),(1),(1),(1)
        ) t(N)
    ),
    E2(N) AS (SELECT 1 FROM E1 a, E1 b),
    E4(N) AS (SELECT 1 FROM E2 a, E2 b),
    E8(N) AS (SELECT 1 FROM E4 a, E4 b)
select @n = ROW_NUMBER() OVER (ORDER BY 1/0) - 1 FROM E8
option (maxdop 1);

print 'a_voronin'
;WITH
    E1(N) AS (
        SELECT * FROM (
            VALUES
                (0),(1),(2),(3),(4),
                (5),(6),(7),(8),(9)
        ) t(N)
    ),
    E2(N) AS (SELECT a.N * 10 + b.N FROM E1 a, E1 b),
    E4(N) AS (SELECT a.N * 100 + b.n FROM E2 a, E2 b),
    E8(N) AS (SELECT a.N * 10000 + b.N FROM E4 a, E4 b)
SELECT @n = N from E8
option (maxdop 1);

set statistics time off;

AlanDenton

 SQL Server Execution Times:
   CPU time = 0 ms,  elapsed time = 0 ms.

 SQL Server Execution Times:
   CPU time = 16411 ms,  elapsed time = 16419 ms.

a_voronin

 SQL Server Execution Times:
   CPU time = 0 ms,  elapsed time = 0 ms.

 SQL Server Execution Times:
   CPU time = 31216 ms,  elapsed time = 31280 ms.