I tried the same tests with the database replicated in a MyISAM
engine. The count was instantaneous but the following still took
3-6seconds:
SELECT * FROM purchased_services WHERE (purchased_services.company_id = 535263)
The following though was instantaneous:
SELECT * FROM purchased_services WHERE (id = 1000)
This is the result from my SHOW INDEX FROM purchased_services:
+--------------------+------------+-------------------------------------+--------------+-------------+-----------+-------------+----------+--------+------+------------+---------+
| Table | Non_unique | Key_name
| Seq_in_index | Column_name | Collation | Cardinality | Sub_part |
Packed | Null | Index_type | Comment |
+--------------------+------------+-------------------------------------+--------------+-------------+-----------+-------------+----------+--------+------+------------+---------+
| purchased_services | 0 | PRIMARY
| 1 | id | A | 627546 | NULL |
NULL | | BTREE | |
| purchased_services | 1 |
purchased_services_company_id_index | 1 | company_id | A
| 627546 | NULL | NULL | YES | BTREE |
|
+--------------------+------------+-------------------------------------+--------------+-------------+-----------+-------------+----------+--------+------+------------+---------+
So I do have the necessary index. I am so confused!!!! Argh...
Your Friend,
John
On 11/25/06, John Kopanas <kopanas@stripped> wrote:
> Sorry about these questions. I am used to working with DBs with less
> then 10K rows and now I am working with tables with over 500K rows
> which seems to be changing a lot for me. I was hoping I can get some
> people's advice.
>
> I have a 'companies' table with over 500K rows and a
> 'purchased_services' table with over 650K rows.
>
> The following query takes over 6 seconds:
> SELECT * FROM purchased_services WHERE (purchased_services.company_id = 535263)
>
> purchased_services.company_id has an index on it.
>
> The following query takes over 3 seconds:
> SELECT count(id) FROM companies;
>
> To me the time it takes to run these queries makes no sense. I would
> imagine both of these queries would take a fraction of a second.
>
> When running some of these queries and looking at 'SHOW processlist' I
> was getting a lot of 'Writing to tmp'.
>
> My DB engine is InnoDB. I am running this on my laptop that is a
> PowerBook 867 with 756 MB of Ram.
>
> Feedback and insight would be greatly appreciated.
>
> Thanks my friends! :-)
>
> --
> John Kopanas
> john@stripped
>
> http://www.kopanas.com
> http://www.cusec.net
> http://www.soen.info
>
--
John Kopanas
john@stripped
http://www.kopanas.com
http://www.cusec.net
http://www.soen.info
