dl and extension directive in php.ini

Hello, I'm hearing some conflicting reports and I'd like to see other's thoughts on this. Loading an external module using dl() at runtime obviously loads the module per request (ie, performance hit). On the other hand, which I believe is the recommended method anyway, is using the extension= directive in php.ini. While this is still a dynamic module load, it should only happen once; for instance when the Apache child process is forked. However, while reading some Zend API docs I began to doubt this, so I'm interested in some confirmations. Basiclly, I'm of the understanding that dl() is 'bad' anyway, so I guess the question really is: when specifying a dynamic module (.so) from php.ini, does it get loaded per request or at process creation time? Thanks, H