Installing/Configuring
PHP Manual

Runtime Configuration

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

MySQLi Configuration Options
Name Default Changeable Changelog
mysqli.allow_persistent "1" PHP_INI_SYSTEM Available since PHP 5.3.0.
mysqli.max_persistent "-1" PHP_INI_SYSTEM Available since PHP 5.3.0.
mysqli.max_links "-1" PHP_INI_SYSTEM Available since PHP 5.0.0.
mysqli.default_port "3306" PHP_INI_ALL Available since PHP 5.0.0.
mysqli.default_socket NULL PHP_INI_ALL Available since PHP 5.0.0.
mysqli.default_host NULL PHP_INI_ALL Available since PHP 5.0.0.
mysqli.default_user NULL PHP_INI_ALL Available since PHP 5.0.0.
mysqli.default_pw NULL PHP_INI_ALL Available since PHP 5.0.0.
mysqli.reconnect "0" PHP_INI_SYSTEM Available since PHP 4.3.5.
mysqli.allow_local_infile "1" PHP_INI_SYSTEM Available since PHP 5.2.4.
mysqli.cache_size "2000" PHP_INI_SYSTEM Available since PHP 5.3.0.

For further details and definitions of the preceding PHP_INI_* constants, see the chapter on configuration changes.

Here's a short explanation of the configuration directives.

mysqli.allow_persistent integer

Enable the ability to create persistent connections using mysqli_connect().

mysqli.max_persistent integer

Maximum of persistent connections that can be made. Set to 0 for unlimited.

The maximum number of MySQL connections per process.

mysqli.default_port integer

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.

mysqli.default_socket string

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

mysqli.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 safe mode.

mysqli.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 safe mode.

mysqli.default_pw string

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

mysqli.reconnect integer

Automatically reconnect if the connection was lost.

mysqli.allow_local_infile integer

mysqli.cache_size integer

Available only with mysqlnd.


Installing/Configuring
PHP Manual