I understand how it works, but the book I'm studying doesn't tell me why you'd want to partition. Could someone shed some light? I can't understand any concept unless I see how it's useful.
Basically, to split up a huge table into smaller sub tables or partitions
- offload data into different files/filegroups (with changes in backup/restore strategy too)
- separate "working" from "historic" data (without having 2+ separate tables which complicates queries)
- allow compression of older data
We're talking 100s of millions of rows and/or high volumes.
You don't partition for a few million rows.