Understanding Slow Query Log

[Adarsh Sharma]

Hi all,

I am using Mysql Ver 14.14 Distrib 5.1.58 in which i enabled slow query log
by setting below parameters in my.cnf :

log-slow-queries=/usr/local/mysql/slow-query.log
long_query_time=100
log-queries-not-using-indexes

I am assuming from the inf. from the internet that long_query_time is in
seconds , but i see the slow query log ,  there are lots of statements (
queries ) :

# User@Host: user1[user1] @ abc.dd.aa.com [192.112.111.111]
# Query_time: 0.052784  Lock_time: 0.000043 Rows_sent: 1  Rows_examined:
141145
SET timestamp=1346409734;
select count(ENTITY_NAME) from ALERT_EVENTS where EVENT_TIME >
date_sub(now(),INTERVAL 60 MINUTE) and status=upper('failed') and
ENTITY_NAME='FETL-ImpressionRC-conversion';
# Time: 120831 10:43:14
# User@Host: user1[user1] @ abc.dd.aa.com [192.112.111.111]
# Query_time: 0.053599  Lock_time: 0.000079 Rows_sent: 1  Rows_examined:
141145
SET timestamp=1346409794;
select count(ENTITY_NAME) from ALERT_EVENTS where EVENT_TIME >
date_sub(now(),INTERVAL 60 MINUTE) and status=upper('failed') and
ENTITY_NAME='FETL-click-enhancer-deferred';
# User@Host: user1[user2] @ abc.dd.aa.com [192.112.111.111]
# Query_time: 0.054185  Lock_time: 0.000086 Rows_sent: 1  Rows_examined:
141145
SET timestamp=1346409794;
select count(ENTITY_NAME) from ALERT_EVENTS where EVENT_TIME >
date_sub(now(),INTERVAL 60 MINUTE) and status=upper('failed') and
ENTITY_NAME='FETL-ImpressionRC-conversion';
# Time: 120831 10:43:22
# User@Host: user2[user2] @ abc.dd.aa.com [192.112.111.111]
# Query_time: 0.000163  Lock_time: 0.000045 Rows_sent: 1  Rows_examined: 13



I don't  understand the query time unit in slow query log because i expect
queries to be logged that takes > 100 s. I tested with sleep command for
60s , it doesn't logged in slow query log and when i sleep for 120 s it
logged but i don't why the other queries are logging in slow log.

# Query_time: 120.000259  Lock_time: 0.000000 Rows_sent: 1  Rows_examined: 0
SET timestamp=1346443103;
SELECT SLEEP(120);

And also my slow log is increasing and decided to purge thorogh below
command :

cat /dev/null > /var/lib/mysql/slow-queries.log


Anyone any ideas about this.


Thanks