Re: Is this too slow?

gene wrote:

> An oracle server that I'm using with some software I've written seems,
> in my judgement, to be way too slow. Since I haven't worked with
> tables of this size in the past, I want to solicit your opinions on
> this.
>
> As an example, this particular query takes about 5 to 6 minutes to
> run:
>
> SELECT count(*), experiment.experiment_id
> FROM experiment, datum
> WHERE experiment.experiment_id = datum.experiment_id and
> experiment.scientist_id = 4
> GROUP BY experiment.experiment_id;
>
> The experiment table has about 700 rows, the datum table has about
> 7,300,000 rows. As the names imply experiment_id is a primary key (not
> null, number(8)) in
> experiment and a foreign key in datum, and is an index in both.
>
> The query above returns 31 grouped rows which represent 366,000
> distinct rows.
> As I said, it takes 5 to 6 minutes to run, which seems to me to be
> very long even with the large table size since I am joining on indexed
> columns.

Without knowledge of your hardware, operating system, and other activity on the box it is impossible to tell you whether this is blazingly fast or glacially slow.

But I must agree that your join to the datum table is hard to understand.

Daniel A. Morgan Received on Sat Jul 21 2001 - 16:37:24 CDT