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Thread: Indexes again

Indexes again

From
Silas Justiniano
Date:
  Sorry, I'll remake (rewrite? redo? ... bad English :/ ) my question:

  I have Books, Authors and Intermediate table. At intermediate I'm
currently using the following indexes:

  CREATE INDEX authorIndex ON Intermediate(author_id);
  CREATE INDEX bookIndex ON Intermediate(book_id);

  I need a third index to not allow duplicated data in my table:

  CREATE UNIQUE INDEX blablabla ON Intermediate(author_id, book_id);

  I'd like to know if, using the third index I can delete one of the
first. Maybe both?

  Thank you! Bye!


--
Silas Justiniano - Brazil

Re: Indexes again

From
Richard Huxton
Date:
Silas Justiniano wrote:
>   Sorry, I'll remake (rewrite? redo? ... bad English :/ ) my question:
>
>   I have Books, Authors and Intermediate table. At intermediate I'm
> currently using the following indexes:
>
>   CREATE INDEX authorIndex ON Intermediate(author_id);
>   CREATE INDEX bookIndex ON Intermediate(book_id);
>
>   I need a third index to not allow duplicated data in my table:
>
>   CREATE UNIQUE INDEX blablabla ON Intermediate(author_id, book_id);
>
>   I'd like to know if, using the third index I can delete one of the
> first. Maybe both?

You can probably delete authorIndex without impacting performance too much.

--
   Richard Huxton
   Archonet Ltd

Re: Indexes again

From
Silas Justiniano
Date:
I know understand. Thank you ;)

On 2/2/06, Richard Huxton <dev@archonet.com> wrote:
> Silas Justiniano wrote:
> >   Sorry, I'll remake (rewrite? redo? ... bad English :/ ) my question:
> >
> >   I have Books, Authors and Intermediate table. At intermediate I'm
> > currently using the following indexes:
> >
> >   CREATE INDEX authorIndex ON Intermediate(author_id);
> >   CREATE INDEX bookIndex ON Intermediate(book_id);
> >
> >   I need a third index to not allow duplicated data in my table:
> >
> >   CREATE UNIQUE INDEX blablabla ON Intermediate(author_id, book_id);
> >
> >   I'd like to know if, using the third index I can delete one of the
> > first. Maybe both?
>
> You can probably delete authorIndex without impacting performance too much.
>
> --
>    Richard Huxton
>    Archonet Ltd
>


--
Silas Justiniano - Brazil