Re: Indexes & Primary Keys (based on the same columns)

Ow Mun Heng wrote:
> I'm wondering if what I'm doing is redundant.
>
> I have a primary key on columns (A,B,C,D)
> and I've also defined an index based on the same columns (A,B,C,D)
>
> and sometimes in the query explain, I see the pkey being used for the
> scan instead of the index.
>
> So.. That made me think perhaps the additional index on the _same_
> parameter is redundant.

A primary key creates an index so having a second index with the same
definition is redundant.

>
> Appreciate comments.
>
>
>
> ---------------------------(end of broadcast)---------------------------
> TIP 9: In versions below 8.0, the planner will ignore your desire to
>        choose an index scan if your joining column's datatypes do not
>        match
>