I recently installed MySQL 5.1 on CentOS 6.2 and had a performance gain over the MySQL 4.1 we are running. So I upgrade the MySQL 5.1 to MySQL 5.5 to see if there was even more of a gain but it actually ran half the speed of the MySQL 5.1 setup.
The test I ran was on a table with 2.3M records with blob notes.
5.1: 57.5899 sec
5.5: 96.3821 sec
What is really interesting is if I pull 100,000 records the 5.5 beats the 5.1 but anything after ends up making the 5.5 load like in spikes; speeds up and slows down as loading which is where the extra seconds seem to be coming from.
Any thoughts to why this is? Same my.cnf for both 5.1 and 5.5
[mysqld] datadir=/var/lib/mysql socket=/var/lib/mysql/mysql.sock user=mysql # Disabling symbolic-links is recommended to prevent assorted security risks symbolic-links=0 bind-address = xxx.xxx.xxx.xxx #This option makes InnoDB to store each created table into its own .ibd file. innodb_file_per_table=1 max_allowed_packet=900M [mysqld_safe] log-error=/var/log/mysqld.log pid-file=/var/run/mysqld/mysqld.pid