php - Allowed memory size of 67108864 bytes exhausted (tried to allocate 4459414 bytes) in writing an xml file -

possible duplicate:
allowed memory size of 33554432 bytes exhausted (tried allocate 43148176 bytes) in php

i've seen similar problems here, mine quite different. reading database , writing xml file. error

<b>fatal error</b>:  allowed memory size of 67108864 bytes exhausted (tried allocate 4459414 bytes) in <b>.../public/home/..</b> on line <b>32</b><br />. 

what should solution? increase memory size in code? help?

do mysql_unbuffered_query() rather mysql_query(). query returning data php server handle.