On 14/08/13 12:02, Robert James wrote:
I noticed that when I have an index on (a,b) of table t, and I do an
SELECT * FROM t ORDER BY a ASC, it doesn't use the index. When I
create a new index of only a, it does use the index. Why is that?
And, more importantly, when I do a query involving a me
On 8/13/13, Robert James wrote:
> I noticed that when I have an index on (a,b) of table t, and I do an
> SELECT * FROM t ORDER BY a ASC, it doesn't use the index. When I
> create a new index of only a, it does use the index. Why is that?
>
> And, more importantly, when I do a query involving a m
