Spinning Drives: The Cost of Out-of-Order Pages
dbo.Users leaf pages, scattered across a hard drive platter
SELECT
*
FROM
dbo.Users
ORDER BY
Id;
-- scan in key order
head seeks:
1
2
3
seek ≈ 8 ms · half a spin ≈ 4 ms
1:300
1:301
1:302
1:845