PHP memory management

http://php.net/manual/kr/features.gc.refcounting-basics.php

http://php.net/manual/kr/features.gc.collecting-cycles.php

http://php.net/manual/kr/features.gc.performance-considerations.php

 

Memory Leaks With Objects in PHP 5

http://paul-m-jones.com/archives/262

 

http://stackoverflow.com/questions/584960/whats-better-at-freeing-memory-with-php-unset-or-var-null