8 messages in com.mysql.lists.javaRe: Re: serious query performance pro...| From | Sent On | Attachments |
|---|---|---|
| Haitao Jiang | 08 Jun 2004 12:03 | |
| Mark Matthews | 08 Jun 2004 12:14 | |
| Haitao Jiang | 08 Jun 2004 12:38 | |
| Kevin Burton | 08 Jun 2004 12:58 | |
| Haitao Jiang | 08 Jun 2004 13:38 | |
| Sanki Poon | 08 Jun 2004 19:31 | |
| Sanki Poon | 08 Jun 2004 19:32 | |
| Sanki Poon | 08 Jun 2004 19:32 |
| Subject: | Re: Re: serious query performance problem when using multiple jdbc connection to mysql |
|---|---|
| From: | Haitao Jiang (jian...@gmail.com) |
| Date: | 06/08/2004 01:38:52 PM |
| List: | com.mysql.lists.java |
They are just the execution time of statement.execQuery(query) - connection creation, statement creation etc are not included in the measurement. I use different threads to executing them at the same time...but I only measure the time of exec the query...these timing are close to what you get when you turn the profileSql=true.
On Tue, 08 Jun 2004 12:59:09 -0700, Kevin Burton <bur...@sofari.com> wrote:
Haitao Jiang wrote:
I am using Connect/J 3.1.1 and mysql 4.1.2, the mysqld runs on a powerful operton machine with 16GB RAM. I am the only user. I have 4 SELECT queries that I tested (results as following). The timing is around execQuery() call. So, jdbc connection creation is not included.
case 1: send via one JDBC connection sequentially: Query 0 took 590ms Query 1 took 431ms Query 2 took 461ms Query 3 took 440ms
case 2: send them at same time using 4 JDBC connections: Query 3 query took 1552ms Query 1 query took 1632ms Query 2 query took 1783ms Query 0 query took 1923ms
I'm willing to bet that the total time of the second query was actually 1923ms in total and that 3,1,and 2 were executed before.
You need to measure total time per thread not real time. Is it total time per thread?
Try to use prep statement caching... and see if that fixes anything.
Kevin
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