Some times you may see the error message like – “PHP Fatal error: Allowed memory size of xxxxx bytes exhausted (tried to allocate xxxxxxx bytes) in Unknown on line 0? while accessing some php pages which indicates that those php files requires more memory for it to execute than the one specified in php.ini file. If the memory_limit value is manipulated in server side php.ini file, it will be applied to all the php files server side.
In order to overcome the error without modifying the server side php.ini file, you need to use the ini_set functionto increase the memory limit inserting the following code in the php file itself. Keep on increasing the memory limit unless the error disappears.