Ow Mun Heng wrote:
> On Sun, 2006-08-20 at 19:59 +1000, chris smith wrote:
>> On 8/20/06, Ow Mun Heng <Ow.Mun.Heng@stripped> wrote:
>>> I'm have a query like so
>>>
>>> select
>>> A,
>>> index_A
>>> from
>>> tableA
>>> join tableB
>>> on tableB.indexA = tableA.indexA
>>>
>>>
>>> select
>>> A,
>>> index_A
>>> from
>>> tableA
>>> join tableB
>>> on tableB.A = tableA.A
>>>
>>> whcih would be more efficient? using the where clause which uses the
>>> index or the one which isn't index?
>> If you join using the field that is indexed, this will use an index.
>>
>> If you join using the field that isn't indexed, it can't use an index.
>
> I take it that that means yes, it's more efficient performance wise to
> always use an index.
Of course, same as any query ;)
