[rt-users] Re: Slow Queries

[Asif Iqbal]

Here is another query that takes 6.95 secs

Count: 198  Time=6.95s (1377s)  Lock=0.00s (0s)  Rows=1.1 (224),
rt_user[rt_user]@localhost
  SELECT DISTINCT main.* FROM (((Tickets main  JOIN Groups Groups_1
ON ( Groups_1.Instance = main.id))  LEFT JOIN CachedGroupMembers
CachedGroupMembers_2  ON ( CachedGroupMembers_2.GroupId = Groups_1.id)
AND ( (CachedGroupMembers_2.GroupId !=
CachedGroupMembers_2.MemberId)))  LEFT JOIN Users Users_3  ON (
Users_3.id = CachedGroupMembers_2.MemberId))   WHERE ((Groups_1.Domain
= 'S')) AND ((Groups_1.Type = 'S')) AND ((main.EffectiveId = main.id))
AND ((main.Status != 'S')) AND ((main.Type = 'S')) AND ( (  (
(Users_3.EmailAddress = 'S') )  ) AND ( (main.Status =
'S')OR(main.Status = 'S') ) )  ORDER BY main.Priority DESC  LIMIT N

Is there a way to improve this?


On 10/9/06, Asif Iqbal <vadud3 at gmail.com> wrote:
> Hi
>
> I am noticing from my slow log file (5 secs) that the following query
> on mysql 4.0.24 is taking a 11 secs
>
> # Query_time: 11  Lock_time: 0  Rows_sent: 299925  Rows_examined: 983836
> use rt3;
> SELECT * FROM Transactions where Transactions.type = 'create';
>
> Now looking at the explain I see
>
> mysql> explain SELECT * FROM Transactions where Transactions.type = 'create';
> +--------------+------+---------------+------+---------+------+--------+-------------+
> | table        | type | possible_keys | key  | key_len | ref  | rows
> | Extra       |
> +--------------+------+---------------+------+---------+------+--------+-------------+
> | Transactions | ALL  | NULL          | NULL |    NULL | NULL | 984572
> | Using where |
> +--------------+------+---------------+------+---------+------+--------+-------------+
>
> It has to go thru about 1 million rows and not using any index.
>
> Is there any index, that I can create, to improve this w/o hurting any
> other query?
>
> --
> Asif Iqbal
> PGP Key: 0xE62693C5 KeyServer: pgp.mit.edu
>


-- 
Asif Iqbal
PGP Key: 0xE62693C5 KeyServer: pgp.mit.edu