Good morning,
A few months back i setup a mysql cluster (2 data nodes, 2 mysql nodes and 1 management node). Last week i noticed that the queries executed slowed down, while the data increase in the database is relative low.
I enabled mysql slow query log on the mysql nodes to see what was going on with slow queries. This morning i looked through the log and found a few strange entries, for example:
# Time: 111207 7:38:36
# User@Host: root[root] @ [aip]
# Query_time: 8.477847 Lock_time: 0.000056 Rows_sent: 1 Rows_examined: 2
SET timestamp=1323239916;
select * from ores where adviseurid=5 and tctabelid=244 and single='1' order by datum asc;
As you can see the rows send and rows examined are low, the lock time is also low. But the time to execute the query is more than 8 seconds.
The amount of rows in the ores table is about 70.000, indexes are in place and used.
I was wondering what could cause the huge query time while there are that few rows send/examined.
Kind regards,
TWan
A few months back i setup a mysql cluster (2 data nodes, 2 mysql nodes and 1 management node). Last week i noticed that the queries executed slowed down, while the data increase in the database is relative low.
I enabled mysql slow query log on the mysql nodes to see what was going on with slow queries. This morning i looked through the log and found a few strange entries, for example:
# Time: 111207 7:38:36
# User@Host: root[root] @ [aip]
# Query_time: 8.477847 Lock_time: 0.000056 Rows_sent: 1 Rows_examined: 2
SET timestamp=1323239916;
select * from ores where adviseurid=5 and tctabelid=244 and single='1' order by datum asc;
As you can see the rows send and rows examined are low, the lock time is also low. But the time to execute the query is more than 8 seconds.
The amount of rows in the ores table is about 70.000, indexes are in place and used.
I was wondering what could cause the huge query time while there are that few rows send/examined.
Kind regards,
TWan