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From:Daniel Koch Date:May 25 1999 9:35pm
Subject:Re: mysql running very slow
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kenford@stripped wrote:

> mysql> EXPLAIN select dom_country from url_info_tb where dom_country='com';
> +-------------+------+---------------+------+---------+------+--------+-----
> -------+
> | table       | type | possible_keys | key  | key_len | ref  | rows   |
> Extra      |
> +-------------+------+---------------+------+---------+------+--------+-----
> -------+
> | url_info_tb | ALL  | NULL          | NULL |    NULL | NULL | 991851 |
> where used |
> +-------------+------+---------------+------+---------+------+--------+-----
> -------+
> 1 row in set (0.21 sec)
>
> At 03:50 PM 5/25/99 -0400, you wrote:
> >kenford@stripped wrote:
> >>
> >> 1. I'm trying to build a search engine using mysql, what can I do to
> >> have mysql be very fast multi cpu, lots of memory, clustering what?
> >>
> >> 2. Is it normal for mysql to take this long to do a search with just
> >> 900,000 documents, what about when I have say 10-20,000,000 documents it
> would
> >> take for ever.
> >>
> >> mysql> select count(dom_country) from url_info_tb;
> >> +--------------------+
> >> | count(dom_country) |
> >> +--------------------+
> >> |             991851 |
> >> +--------------------+
> >> 1 row in set (0.02 sec)
> >>
> >> 2.
> >> mysql> select dom_country from url_info_tb where dom_country='edu';
> >>
> >> | edu         |
> >> | edu         |
> >> | edu         |
> >> | edu         |
> >> | edu         |
> >> +-------------+
> >> 80 rows in set (34.39 sec)
> >

EXPLAIN tells you that you don't have an index on dom_country.

Try this:

mysql> alter table url_info_tb add index dom_country_index (dom_country);

If it complains about 'dom_country' not being defined as NOT NULL, use this
first:

mysql> alter table url_info_tb modify column dom_country char(11) not null;  #
or whatever length dom_country should be

Regards,

--
Dan Koch
Webmaster
American City Business Journals
http://www.amcity.com/


Thread
mysql running very slowkenford25 May
  • Re: mysql running very slowJim Faucette25 May
Re: mysql running very slowkenford26 May
  • Re: mysql running very slowDaniel Koch26 May