DROP TABLE dbo.T

-- rn must have contiguous values for this to work:
CREATE TABLE dbo.T (rn int PRIMARY KEY, f float NOT NULL)

-- 100000 random floats between 0 and 1:
INSERT INTO dbo.T
SELECT n+1 AS rn, RAND(CAST(NEWID() AS binary(4))) AS f
FROM dbo.Numbers
GO

;WITH RT AS (
  SELECT rn, f AS rt
  FROM dbo.T
  WHERE rn = 1

  UNION ALL

  SELECT T.rn, RT.rt + T.f
  FROM RT
  INNER JOIN dbo.T AS T
    ON T.rn = RT.rn + 1
)
SELECT *
INTO dbo.TRT
FROM RT
--ORDER BY rn
OPTION (MAXRECURSION 0)

SQL Server parse and compile time: 
   CPU time = 0 ms, elapsed time = 1 ms.
Table 'Worktable'. Scan count 2, logical reads 600001, physical reads 0,
read-ahead reads 0, lob logical reads 0, lob physical reads 0, lob read-ahead reads 0.
Table 'T'. Scan count 100000, logical reads 200002, physical reads 0,
read-ahead reads 0, lob logical reads 0, lob physical reads 0, lob read-ahead reads 0.

SQL Server Execution Times:
   CPU time = 3500 ms,  elapsed time = 3724 ms.

(100000 row(s) affected)

SELECT * FROM dbo.T AS T1 INNER JOIN dbo.T AS T2 ON T1.rn = T2.rn + 1
SELECT * FROM dbo.T AS T1 INNER JOIN dbo.T AS T2 ON T1.rn - 1 = T2.rn

quote:

---

Originally posted by Arnold Fribble

SELECT * FROM dbo.T AS T1 INNER JOIN dbo.T AS T2 ON T1.rn = T2.rn + 1
SELECT * FROM dbo.T AS T1 INNER JOIN dbo.T AS T2 ON T1.rn - 1 = T2.rn

---