SQL Server B-Tree: The Leaf Level Is a Doubly Linked List dbo.Users — clustered index on Id (identity) SELECT * FROM dbo.Users WHERE Id BETWEEN 9500 AND 13800 ORDER BY Id; SELECT TOP 4 * FROM dbo.Users ORDER BY Id DESC; Leaf · data pages · Level 0 Page 1:300 Id 1 Id 2,900 Id 5,750 Id 7,200 Page 1:301 Id 8,001 Id 9,500 Id 11,000 Page 1:845 Id 12,345 Id 13,800 Id 15,200 added later by a page split Page 1:302 Id 16,001 Id 18,500 Id 21,000 next prev