… frequent cases with performance problems with MySQL is what they happen every so often or certain times. Investigating them we find out… cause is some batch jobs, reports and other non response time critical activities are overloading the system causing user experience to… need to know it is not MySQL problem, might be even not problem with your MySQL configuration, queries and hardware, even though fixing…
Comment: Benchmarking single-row insert performance on Amazon EC2
May 16, 2012 By 11 Comments
… few GB of main memory). The cost of querying this database will be 10 times higher with this partitioning, however since you’ll have to look in each of the ten partitions to query one…://bazaar.launchpad.net/~mdcallag/mysql-patch/mytools/annotate/head%3A/bench/ibench/iibench.py) is that it measures query performance too, so…
Post: Join Optimizations in MySQL 5.6 and MariaDB 5.5
April 4, 2012 By 2 Comments
…_buffer_size set to 6M, the query time for MySQL 5.6 becomes approximately equal to that of MySQL 5.5. MariaDB 5.5… slow as compared to both MySQL 5.5 and MySQL 5.6. For MariaDB 5.5 the query time decreases when the join_buffer… bound and the query time drops from 2534.41s down to under a minute. MySQL 5.6 has the smallest query time when the join…
Post: Multi Range Read (MRR) in MySQL 5.6 and MariaDB 5.5
March 21, 2012 By 10 Comments
… query time for MySQL 5.6, increase of 0.02s. But the query times for MariaDB 5.5 are greater than both MySQL 5.5 and MySQL… MRR, and the query time for MySQL 5.6 and MariaDB 5.5 jumps to ~11min (this is the query time for MySQL 5.5) While when it sticks to plan ‘b’ for MySQL 5.6 and MariaDB 5.5, then query times remain…
Post: Troubleshooting MySQL Memory Usage
March 21, 2012 By 3 Comments
…Percona Server you can do better as you can query temporary tables too: mysql> select sum(data_length+index_length) from …LENGTH: 0 DATA_LENGTH: 16384 INDEX_LENGTH: 0 CREATE_TIME: NULL UPDATE_TIME: NULL *************************** 2. row *************************** SESSION_ID: 7234 TABLE_SCHEMA: …
Post: Joining many tables in MySQL - optimizer_search_depth
April 20, 2012 By 6 Comments
… automatically. Making this change I could bring optimization, and full query execution time to less than 50ms. Low values, such as 3… further I found the following explanation from Timour Katchaounov in MySQL mailing list archives I have some recollection that there were… plan computation would be more important than backward compatibility. In MySQL 5.6 things are likely to get even better handling…
Post: Introducing the pmp-check-mysql-status Nagios Plugin
March 29, 2012 By Leave a Comment
… to be frequent, severe, or subtle causes of problems in MySQL systems. They are intentionally not generic because I wanted to… of status counters and variables. This is the pmp-check-mysql-status plugin, which can perform computations on status variables. By… percentage Compute the rate of change over time for one or more counters (e.g. queries per second) The documentation contains examples…
Post: How FLUSH TABLES WITH READ LOCK works with Innodb Tables
March 23, 2012 By 20 Comments
… WRITE query blocks any READ queries to execute on the table. mysql> show processlist; +——-+——+———–+———-+————+——+——————————+——————————+———–+—————+———–+ | Id | User | Host | db | Command | Time | State…
Post: Index Condition Pushdown in MySQL 5.6 and MariaDB 5.5 and its performance impact
March 12, 2012 By 12 Comments
… in preparation for the talk comparing the optimizer enhancements in MySQL 5.6 and MariaDB 5.5. We are taking a… optimizer enhancement Index Condition Pushdown (ICP). Its available in both MySQL 5.6 and MariaDB 5.5 Now let’s take…
Comment: Too many connections? No problem!
March 15, 2012 By 28 Comments
…=/data/mysql socket=/data/mysql/mysql.sock max_connections = 600 wait_timeout = 60 interactive_timeout=1800 skip-name-resolve skip-bdb default-time-zone=America/Caracas log-slow-queries=/var/log/mysql-slow-queries.log long_query_time=15 log-queries-not-using-indexes query_cache_type=1 query_cache…
