Re: Informix SQL question

I'm sure ! In article <01bd8fd3$d744e590$17c8c8c8@saturno>, "Rui Domingos" <rui.domingos@psidoc.pt> wrote: > > I think the optimizer takes care of that, but I'm not sure. > > Candy McCall <candym@olcinc.com> wrote in article > <6l58c9$j8v$1@news.xmission.com>... > > > > This is a multi-part message in MIME format. > > > > ------=_NextPart_000_004F_01BD8F43.26C88C20 > > Content-Type: text/plain; > > charset="iso-8859-1" > > Content-Transfer-Encoding: quoted-printable > > > > I have a simple question. Suppose you have a table whose primary key is > = > > a composite > > key of the columns col1,col2,col3,col4 (primary key is in that order). = > > If you do a query to=20 > > fetch a record by the primary key, does it matter what order you ask for > = > > the columns=20 > > in the where clause? > > > > For example, does =20 > > SELECT * FROM someTable WHERE col4=3D? AND col1=3D? AND > > col2=3D? AND col3=3D? =20 > > get the record as efficiently as the statement > > SELECT * FROM someTable WHERE col1=3D? AND col2=3D? AND col3=3D? AND> = > > col4=3D? > > > > I always order the columns in the where clause in the order of the = > > primary key or the > > index I'd like the optimizer to use. I've noticed in the IBM Visual Age > = > > for Java that some > > of the code generated to retrieve a row by a primary key may mix up the = > > order. > > > > Thanks! > > > > Candy > > -- > > Candy McCall > > ONLINE Computing, Inc. > > (candym@olcinc.com) -----== Posted via Deja News, The Leader in Internet Discussion ==----- http://www.dejanews.com/ Now offering spam-free web-based newsreading