Re: Performance woes

On Sat, 10 Dec 2005, Benjamin Smith wrote:

> A few questions:
>
> 1) Let's assume that I have some multipile foreign keys, and I join on three
> values. For example:
>
> Create table gangsters (
>     name varchar not null,
>     birthdate integer not null,
>     shirtnumber integer not null,
>     primary key (name, birthdate, shirtnumber);
>
> create table children (
>     father_name varchar not null,
>     father_bd integer not null,
>     father_shirtnumber integer not null,
>     birthdate integer not null,
>     name varchar not null,
>     foreign key (father_name, father_bd, father_shirtnumber) REFERENCES
>         gangsters(name, birthdate, shirtnumber)
>     );
>
> We have two table declarations, each with implicit indexes:
>     1) table gangsters has a primary_key index on name, birthdate, shirtnumber.
>     2) children has an implicit index on father_name, father_bd,
> father_shirtnumber. (right?)

AFAIK, not unless you create one.

Explain analyze output for the query would probably be useful as well.