Re: CHECK vs REFERENCES

On Fri, 9 Sep 2005, Michael Fuhr wrote:

> On Sat, Sep 10, 2005 at 12:23:19AM -0300, Marc G. Fournier wrote:
>> Which is faster, where the list involved is fixed? My thought is that
>> since it doesn't have to check a seperate table, the CHECK itself should
>> be the faster of the two, but I can't find anything that seems to validate
>> that theory ...
>
> Why not just benchmark each method as you intend to use them? Here's
> a simplistic example:
>
> CREATE TABLE test_none (
> val integer NOT NULL
> );
>
> CREATE TABLE test_check (
> val integer NOT NULL CHECK (val IN (1, 2, 3, 4, 5))
> );
>
> CREATE TABLE test_vals (
> id integer PRIMARY KEY
> );
> INSERT INTO test_vals SELECT * FROM generate_series(1, 5);
>
> CREATE TABLE test_fk (
> val integer NOT NULL REFERENCES test_vals
> );
>
> \timing
>
> INSERT INTO test_none SELECT 1 FROM generate_series(1, 100000);
> INSERT 0 100000
> Time: 3109.089 ms
>
> INSERT INTO test_check SELECT 1 FROM generate_series(1, 100000);
> INSERT 0 100000
> Time: 3492.344 ms
>
> INSERT INTO test_fk SELECT 1 FROM generate_series(1, 100000);
> INSERT 0 100000
> Time: 23578.853 ms

Yowch, I expected CHECK to be better ... but not so significantly ... I
figured I'd be saving milliseconds, which, on a busy server, would add up
fast ... but not 10k' of milliseconds ...

Thanks, that definitely shows a major benefit ...

----
Marc G. Fournier Hub.Org Networking Services (http://www.hub.org)
Email: scrappy(at)hub(dot)org Yahoo!: yscrappy ICQ: 7615664