Tim Van Wassenhove home

A while ago i presented my approach to generate a nums table here.

DECLARE @count INT = 1000;

WITH    
  [Nums1] AS ( SELECT 1 AS [Value] UNION SELECT 2 AS [Value] ) 
, [Nums2] AS ( SELECT A.* FROM [Nums1] AS A, [Nums1] AS B, [Nums1] AS C)  
, [Nums3] AS ( SELECT A.* FROM [Nums2] AS A, [Nums2] AS B, [Nums2] AS C)
, [Nums4] AS ( SELECT A.* FROM [Nums3] AS A, [Nums3] AS B )
, [Numbers] AS ( SELECT TOP(@count) -1 + ROW_NUMBER() OVER(ORDER BY [Value]) AS [Value] FROM[Nums4] )
  
SELECT * FROM [Numbers];

Because we only use this code once to fill the table we don’t really care that it is not very fast. Today i discovered there is a way to speed it up in this wonderful book: Inside Microsoft® SQL Server® 2008: T-SQL Querying:

WITH
      
  [Nums1] AS ( SELECT 1 AS [Value] UNION SELECT 2 AS [Value] )  
, [Nums2] AS ( SELECT A.* FROM [Nums1] AS A, [Nums1] AS B, [Nums1] AS C)
, [Nums3] AS ( SELECT A.* FROM [Nums2] AS A, [Nums2] AS B, [Nums2] AS C)
, [Nums4] AS ( SELECT A.* FROM [Nums3] AS A, [Nums3] AS B )
, [Numbers] AS ( SELECT TOP(@count) -1 + ROW_NUMBER() OVER(ORDER BY (SELECT 0)) AS [Value] FROM[Nums4] )
  
SELECT * FROM [Numbers];

Yay for features like ORDER BY (SELECT ).