There is good chance you are familiar with this error.
Fatal Error: Allowed memory size of XXXXXXX bytes exhausted tried to allocate XXXXX bytes
What’s the cause of this error. How you prevent your PHP script running out of memory. Let’s talk about it. In any programming language memory is cleared up by the garbage collector. And garbage collector does this work perfectly. For clearing up the memory, you need to tell the garbage collector that the following allocated memory is ready to free. In PHP this can be done by calling unset().