Does MySQL have query queues and what's behind query_time in the slow log?
mysql,queue,execution-time,mysql-slow-query-log
There are no queues like you describe. When the query starts, the connection is dedicated to running it. It may be blocked by any of a large number of "mutexes" because of various things shared between connections. As the query runs, it may have to wait for I/O to read...
Mysql slow log: simple select query takes 26 seconds
mysql,database,mysql-slow-query-log
It might be faster if you force it to use the primary key instead of doing a full table scan. Try doing SELECT tag FROM tags USE INDEX(PRIMARY) if you are using innodb. Alternatively, you could also just add WHERE tag_id > 0 to your query. From my understanding, innodb...
How to speed up slow MySQL UPDATE queries with InnoDB tables
php,mysql,innodb,mysql-slow-query-log
It's using the wrong key instead of the index on the 3 columns. You can hint at indexes with USE KEY ... syntax. https://dev.mysql.com/doc/refman/5.1/en/index-hints.html You may also want to try reordering your key on the 3 columns. Generally, you want the most restricting column to be first in the index,...
NOT IN subquery takes too long to execute
Here is another version of your query select distinct e.EmployeeId FROM employees e left join attendance a on e.EmployeeId = a.EmployeeId and a.AttendanceDate = '2015-01-20' where e.status='Active' and e.BranchId= '2' and a.EmployeeId is null You will also need some indexes to be applied on the tables as alter table employees...
MySQL's EXPLAIN INSERT unavailable: how to understand if INSERT is slow or not?
php,mysql,performance,innodb,mysql-slow-query-log
INSERT must update all the indexes for each row inserted. However, for a single row, we are talking milliseconds at most. INSERT ... SELECT ... can be inserting arbitrarily many rows -- either the SELECT or the INSERT could be the problem. INSERT ... VALUES (1,2,3), (4,5,6), ... (a 'batched'...
Identify slow query without slow query logs in mysql server
I find the slow to be the best source of what is bogging down the server. Suggest you start will a moderately high value of long_query_time. This will minimize the I/O and disk space. Fix the queries that it finds, if you can. When you have exhausted that, lower that...