One of the very frequent cases with performance problems with MySQL is what they happen every so often or certain times… need to know it is not MySQL problem, might be even not problem with your MySQL configuration, queries and hardware, even though…
Comment: What to tune in MySQL Server after installation
April 28, 2012 By 116 Comments
… is given below. Because there are several queries with while loop in my application. I request to all please help me… at com.mysql.jdbc.StandardSocketFactory.connect(StandardSocketFactory.java:156) at com.mysql.jdbc.MysqlIO.(MysqlIO.java:276) at com.mysql.jdbc.Connection.createNewIO(Connection.java:2641) at com.mysql.jdbc.Connection.(Connection.java:1531) at com.mysql.jdbc.NonRegisteringDriver.connect…
Comment: Moving Subtrees in Closure Table Hierarchies
May 2, 2012 By 7 Comments
… closure table hierarchy to store regions in a database using MySQL and I’m wondering how can I create a unordered… so because you’re “walking the path”. I’m using MySQL, PHP or Coldfusion (I have to do it in both… and then put it in an array or structure to loop over… Thanks, Annie.
Post: Join Optimizations in MySQL 5.6 and MariaDB 5.5
April 4, 2012 By 2 Comments
… briefly explain these optimizations. Batched Key Access Traditionally, MySQL always uses Nested Loop Join to join two or more tables. What this… As I have told before MySQL has only supported one join algorithm and that is Nested Loop Join. MariaDB has introduced a… a look at the status counters. Counter Name MySQL 5.5 MySQL 5.6 MySQL 5.6 w/ join_buffer_size=6M & read…
Comment: How to load large files safely into InnoDB with LOAD DATA INFILE
March 29, 2012 By 28 Comments
…,1) eq “\\”) { $line .= ; } } right at the beginning of the main loop. Then it works for me like a charm transferring the… , varchar columns). Also, rather then time’ing the mysql commands in the loop (second shell), I added –show-warnings to the command…
Comment: How FLUSH TABLES WITH READ LOCK works with Innodb Tables
March 27, 2012 By 20 Comments
… script that is constantly recloning a database now, in a loop, until that produces an InnoDB clone that is unrecoverable. I… records to the database… … InnoDB: Apply batch completed InnoDB: Last MySQL binlog file position 0 15906301, file name ../log/binlog.000290…
Post: Infinite Replication Loop
October 10, 2011 By 2 Comments
… with infinite replication loops. I decided to write a blog post about these infinite loop of binary log statements in MySQL Replication. To… mysql 1 Note: you can also check all the statements that were in the loop using mysqlbinlog. For example what was the loop of events from server-id 2? # mysqlbinlog mysql-relay-bin.000x…
Post: How to debug long-running transactions in MySQL
March 8, 2011 By 6 Comments
… space (${full}%, ${avail}MB free)”>&2 exit 1 fi host=$(mysql -ss -e ‘SELECT p.HOST FROM information_schema.innodb_lock… port 3306 and port ${port} > /root/tcpdumps/`date +%s`-tcpdump & mysql -e ‘show innodb status\Gshow full processlist’ > /root/tcpdumps/`date +%s…, small transactions. Don’t design batch jobs that run in loops and update data, unless you make them commit between iterations…
Post: Is your MySQL Application having Busy IO by Oracle Measures ?
January 8, 2012 By 1 Comment
…. 500MB/sec would be exceptional for traditional MySQL as MySQL optimizer with its nested loops joins does not favor sequential scans even for… – many what would be considered medium scale MySQL installations would get there. With MySQL we seems to prefer to run more low… is to continue to be significant difference between MySQL and Oracle deployments, yet as MySQL is getting better and better handling large…
Post: Troubleshooting MySQL Upgrade Performance Regressions
February 15, 2012 By Leave a Comment
… it without side load. Setting up 2 MySQL Servers side by side (for example with MySQL Sandbox) can especially be helpful. Once you have spotted the query which performs differently between MySQL Server versions you should: Check Query Plan Run EXPLAIN to… PROFILE to see where differences are. Running query in the loop and getting o_profile sample can also be a good…
