Re: Using indexes

Man I am tired of this question. I have updated the FAQ:

<P>Indexes are usually not used for <SMALL>ORDER BY</SMALL>
or joins: a sequential scan followed by an explicit sort is
faster than an indexscan of all tuples of a large table, because it
takes fewer disk accesses.</P>

> Hi,
>
> Indexes are used to find a record faster in a table.
>
> It only seems to work if I am working with one table.
> eg)
> > create index customer_id_idx on customer(id);
> > select * from customer where id=1;
> -- This uses the index I create
>
> However, when I start to join 2 or more tables together it doesn't seem
> to use it.. WHY???
>
> eg)
> > create index customer_id_idx on customer(id);
> > select * from customer, purchaseorder where customer.id=purchaseorder.id;
>
> -- This results in a seq scan .. WHY??
>
> Is there a way to make it so that it uses my index
>
> Thanks again.
>
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