Something like this perhaps?
WITH CTE AS
(
SELECT 11011 AS CUSTOMERID, GETDATE() AS LoadDate
UNION ALL
SELECT 11011, LoadDate + 1
FROM CTE
),
Milestones AS
(
SELECT TOP 100 CustomerID, LoadDate=CAST(LoadDate AS DATE)
FROM CTE
),
DateRanges AS
(
SELECT CustomerID,LoadDate
,rn=30*(1+(ROW_NUMBER() OVER (PARTITION BY CustomerID ORDER BY LoadDate)-1)/30)
FROM Milestones
)
SELECT *
FROM DateRanges;
My thought question: Have you ever been told that your query runs too fast?
My advice:
INDEXing a poor-performing query is like putting sugar on cat food. Yeah, it probably tastes better but are you sure you want to eat it?
The path of least resistance can be a slippery slope. Take care that fixing your fixes of fixes doesn't snowball and end up costing you more than fixing the root cause would have in the first place.
Need to UNPIVOT? Why not CROSS APPLY VALUES instead?[/url]
Since random numbers are too important to be left to chance, let's generate some![/url]
Learn to understand recursive CTEs by example.[/url]
[url url=http://www.sqlservercentral.com/articles/St