T E Schmitz wrote:
> Hello,
>
> I have created the following join table: the two FKs are the PK of the
> table. Typically, I will need to select rows for a given ITEM_FK.
>
> Question: is it necessary/advisable to create an index for the ITEM_FK
> column? Or is this redundantbecause this column is already one of the PK
> columns?
>
> CREATE TABLE SUPPLY
> (
> ITEM_FK integer NOT NULL,
> CONTACT_FK integer NOT NULL,
> COST numeric (7,2),
> PRIMARY KEY (ITEM_FK,CONTACT_FK)
> );
The primary-key index can be used for ITEM_FK but not CONTACT_FK, so you
might want an index on that column.
-- Richard Huxton Archonet Ltd
