Table partitioning in SQL 2008 - Why?

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.

StackExchange Database Administrators Q#11721, answer score: 10