MySQL 5.4 is based on MySQL 5.1 but includes small, high-impact changes to improve MySQL Server performance, particularly with regard to scalability. These changes exploit advances in hardware and CPU design and enable better utilization of existing hardware.
MySQL 5.4 incorporates work from several sources,
InnoDB Plugin from Oracle Corp.,
community patches, and modifications developed by MySQL
Scalability and Performance Project members and other MySQL
engineers. For information about features of
Plugin, see the
InnoDB Plugin Manual
The following list summarizes MySQL 5.4 areas of emphasis that distinguish it from MySQL 5.1. The following sections describe these features in more detail.
The principal emphasis is to improve scalability on
multi-core CPUs. The trend in hardware development now is
toward more cores rather than continued increases in CPU
clock speeds, which renders “wait until CPUs get
faster” a nonviable means of improving database
performance. Instead, it is necessary to make better use of
multiple cores to maximally exploit the processing cycles
they make available. MySQL 5.4 takes advantage
of features of SMP systems and tries to eliminate
bottlenecks in MySQL architecture that hinder full use of
multiple cores. The focus has been on
InnoDB, especially locking and
InnoDB I/O Subsystem changes.
InnoDB I/O subsystem changes
enable more effective use of available I/O capacity.
Enhanced Solaris support. Several modifications improve operation of MySQL Server on Solaris.
Diagnostic and monitoring capabilities.
There is better access to execution and performance
information. Diagnostic improvements include DTrace probes,
ENGINE INNODB STATUS output, and a new status
Configuration changes. The “out of box” configuration provides better choices of default option and system variable values for MySQL operation on up to 16-way x86 servers and 64-way CMT servers with 4GB or more memory.
The following constructs are deprecated and are removed as of MySQL 5.5. Where alternatives are shown, applications should be updated to use them.
SHOW TABLE TYPES SQL statement (use
SHOW PLUGIN SQL statement (use
data type: The ability to specify a display width of
N (use without
server options to set replication parameters (use the
CHANGE MASTER TO statement