PHP MySQL - Stilson.net

www.it-ebooks.infoCHAPTER 26 • INSTALLING AND CONFIGURING MYSQLtweaking the startup parameters—as well as the behaviors—of many MySQL clients, includingmysqladmin, myisamchk, myisampack, mysql, mysqlcheck, mysqld, mysqldump, mysqld_safe, mysql.server,mysqlhotcopy, mysqlimport, and mysqlshow. You can maintain these tweaks within MySQL’sconfiguration file, my.cnf.At startup, MySQL looks in several directories for the my.cnf file, with each directory determiningthe scope of the parameters declared within. The location and relative scope of each directory ishighlighted here:• /etc/my.cnf (C:\my.cnf or windows-sys-directory\my.ini on Windows): Globalconfiguration file. All MySQL server daemons located on the server refer first tothis file. Note the extension of .ini if you choose to place the configuration file inthe Windows system directory.• DATADIR/my.cnf: Server-specific configuration. This file is placed in the directoryreferenced by the server installation. A somewhat odd, yet crucial characteristic ofthis configuration file is that it references only the data directory specified atconfiguration time, even if a new data directory is specified at run time. Note thatMySQL’s Windows distribution does not support this feature.• --defaults-extra-file=name: The file specified by the supplied file name,complete with absolute path.• ~/.my.cnf: User-specific configuration. This file is expected to be located in theuser’s home directory. Note that MySQL’s Windows distribution does not supportthis feature.You should understand that MySQL attempts to read from each of these locations at startup. Ifmultiple configuration files exist, parameters read in later take precedence over earlier parameters.Although you could create your own configuration file, you should base your file upon one of fivepreconfigured my.cnf files, all of which are supplied with the MySQL distribution. These templates arehoused in INSTALL-DIR/support-files (on Windows these files are found in the installation directory).The purpose of each is defined in Table 26-1.Table 26-1. MySQL Configuration TemplatesNamemy-huge.cnfmy-innodb-heavy-4G.cnfmy-large.cnfmy-medium.cnfDescriptionIntended for high-end production servers, containing 1 to 2GB RAM,tasked with primarily running MySQLIntended for InnoDB-only installations for up to 4GB RAM involvinglarge queries and low trafficIntended for medium-sized production servers, containing around512MB RAM, tasked with primarily running MySQLIntended for low-end production servers containing little memory(less than 128MB)501