Whether to pool ODBC connections. Can be one of "strict", "relaxed" or "off" (equals to ""). The parameter describes how strict the connection manager should be when matching connection parameters to existing pooled connections. strict is the recommend default, and will result in the use of cached connections only when all the connection parameters match exactly. relaxed will result in the use of cached connections when similar connection parameters are used. This can result in increased use of the cache, at the risk of bleeding connection information between (for example) virtual hosts.

This setting can only be changed from the php.ini file, and affects the entire process; any other modules loaded into the process that use the same ODBC libraries will be affected too, including the Unified ODBC extension.