Difference between 2 indexes with columns defined in reverse order

Question

Are there any differences between following two indexes?

• IDX_IndexTables_1
• IDX_IndexTables_2

If there are any, what are the difference

Answer 1

Other folk have answered that they are different, and I agree.

I'll add some other thoughts though...

• the (col1, col2) index means you don't need an index on col1 alone
• the (col2, col1) index means you don't need an index on col2 alone
• the order matters if this is covering (eg WHERE on col1, SELECT col2)
• the direction (ASC/DESC) also matters (Other question 1, Other question 2)