Sergei Dubov wrote:
>
> This will automatically create a unique index on the primary key.
>
> Well, if I do a query later like:
>
> select * from table_a where table_b_id=1,
>
> will the query use an index? Will this be true when I do join on this
> table?
Yes to both (if the query plan thinks that is the most efficient way).
Of course a query on "table_c_id" can't use the index.
--
Richard Huxton
Archonet Ltd