Runtime Configuration

The behaviour of these functions is affected by settings in php.ini.

MySQL Configuration Options

Name	Default	Changeable	Changelog
mysql.allow_persistent	"1"	PHP_INI_SYSTEM
mysql.max_persistent	"-1"	PHP_INI_SYSTEM
mysql.max_links	"-1"	PHP_INI_SYSTEM
mysql.trace_mode	"0"	PHP_INI_ALL	Available since PHP 4.3.0.
mysql.default_port	NULL	PHP_INI_ALL
mysql.default_socket	NULL	PHP_INI_ALL	Available since PHP 4.0.1.
mysql.default_host	NULL	PHP_INI_ALL
mysql.default_user	NULL	PHP_INI_ALL
mysql.default_password	NULL	PHP_INI_ALL
mysql.connect_timeout	"60"	PHP_INI_ALL	PHP_INI_SYSTEM in PHP <= 4.3.2. Available since PHP 4.3.0.

For further details and definitions of the PHP_INI_* constants, see the php.ini directives.

Here's a short explanation of the configuration directives.

mysql.allow_persistent boolean

Whether to allow persistent connections to MySQL.

mysql.max_persistent integer

The maximum number of persistent MySQL connections per process.

mysql.max_links integer

The maximum number of MySQL connections per process, including persistent connections.

mysql.trace_mode boolean

Trace mode. When mysql.trace_mode is enabled, warnings for table/index scans, non free result sets, and SQL-Errors will be displayed. (Introduced in PHP 4.3.0)

mysql.default_port string

The default TCP port number to use when connecting to the database server if no other port is specified. If no default is specified, the port will be obtained from the MYSQL_TCP_PORT environment variable, the mysql-tcp entry in /etc/services or the compile-time MYSQL_PORT constant, in that order. Win32 will only use the MYSQL_PORT constant.

mysql.default_socket string

The default socket name to use when connecting to a local database server if no other socket name is specified.

mysql.default_host string

The default server host to use when connecting to the database server if no other host is specified. Doesn't apply in SQL safe mode.

mysql.default_user string

The default user name to use when connecting to the database server if no other name is specified. Doesn't apply in SQL safe mode.

mysql.default_password string

The default password to use when connecting to the database server if no other password is specified. Doesn't apply in SQL safe mode.

mysql.connect_timeout integer

Connect timeout in seconds. On Linux this timeout is also used for waiting for the first answer from the server.