Re: Efficient query to fetch the columns in an entire relation?

Tobin Harris wrote:
>
> > Yesterday, I came across one simple question yet interesting.
> >
> > What is the best way of retrieving all columns in a given relation
> > using a SQL query.
> >
> > Two possible alternatives are
> >
> > 1. SELECT * FROM relation_name;
> >
> > 2. SELECT COLUMN1, COLUMN2, ..., COLUMNn FROM relation_name;
> >
> > I am not able to decide, which is better than the other and more
> > importantly
> > WHY?
>
> I'm pretty sure that option 2 is best. If you explicitly state the columns
> you want, the database doesn't have to waste effort querying the
> data-dictionary to work out what columns are available to select.
>
As usual, the crux is in the operationalization of 'best'. An alternative approach: if you want something that will always return all columns, even in an environment where tables are changed regularly, you should use the 'select *'. It is amore robust and low maintenance solution.

Regards,

Ruud.

> Tobin
>
> > Hope to get some reply on this,
> >
> > - Vijay

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Ruud de Koter                    HP OpenView Software Business Unit
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