… “Questions” or “Com_select” to get amount of IO per query or per Select. It is good to check it over certain intervals – some… a lot. How to get CPU consumption per query ? You can take a look at procfs for MySQL process: root@ubuntu:/var/log/mysql# cat /proc… Server, enabled full query logging and log_slow_verbosity=full you can also get great amount of related data from mk-query-digest report…
Post: How to load large files safely into InnoDB with LOAD DATA INFILE
July 3, 2008 By 29 Comments
… gets bloated and slow. Even simple SELECT queries might have to scan through lots of obsolete, but not…I chose 1M because the rows were small). But how to do this without splitting the file? The answer… ]; do time mysql -e “set foreign_key_checks=0; set sql_log_bin=0; set unique_checks=0; load data…
Post: Troubleshooting MySQL Memory Usage
March 21, 2012 By 5 Comments
…how much memory they use). Memory Tables MEMORY tables can take memory. There are implicit MEMORY tables which are allocated for query…to check which sessions have created which temporary tables (both in memory and not): mysql…
Post: Reasons for MySQL Replication Lag
July 29, 2011 By 9 Comments
…to analyze your replication traffic regularly with mk-query-digest (Percona Server marks Slave Thread in slow query log so it is easy to…query-digest is a great way to deal with it. Note you need not only to check the types and frequencies of queries but also how…
Post: Profiling MySQL Memory Usage With Valgrind Massif
January 9, 2013 By 3 Comments
…) it was allocated, how it got there…a particular query. Or, …to point mysqld to your settings file etc. After mysqld is properly started (check if you can login with your mysql…Log_event::read_log_event(st_io_cache*, st_mysql_mutex*, Format_description_log_event const*) (in /usr/local/percona/mysql…
Post: Troubleshooting MySQL Upgrade Performance Regressions
February 15, 2012 By Leave a Comment
…to use pt-query-digest to compare workloads on servers. Best if you can analyze full query logs…how query is written and provide the hints. Check Query Execution If query execution plan looks the same it is good to check whenever it seems to…
Post: Upgrading MySQL
January 5, 2010 By 24 Comments
… 4.1 to 5.1 just because so much more people have followed that road. So how do… get query log (you can use mk-query-digest with tcpdump to sniff out queries if you can’t enable log for … tool to run comparison. The tool will run SELECT queries on both new and old MySQL installations and check result …
Post: MySQL 4 to MySQL 5 Upgrade performance regressions
June 6, 2007 By 8 Comments
… likely MySQL 5.0 and 5.1 would not get any fixes for this problem, so lets see who is affected, how to check you’re affected and how to fix it. Who is affected ? The good thing… “commit” queries in the processlist for multiple statement transactions. Looking at SHOW INNODB STATUS you would notice large amount of log writes…
Post: Auditing login attempts in MySQL
December 28, 2012 By 4 Comments
…to audit MySQL‘s authentication process is to get all the information we need from logs. General Query Log The first option is the General Query Log…to log access denied messages to the error log. We just need to enable log_warnings with a value greater than 1: log_warnings = 2 Then check…
Post: MySQL Slow query log in the table
May 31, 2007 By 1 Comment
…MySQL 5.1 get MySQL slow query log logged in mysql.slow_log…to MyISAM, disable concurrent inserts and run long reporting query on the log file query execution is still proceeds. I have not checked…
