wp-db fatal error – allowed memory size exhausted

|| fatal error wp-db.php on wordpress

Fatal error: Allowed memory size of 33554432 bytes exhausted (tried to allocate 137535 bytes) in /home/websitep/public_html/wp-includes/wp-db.php on line 906

|| how to fix wp-db fatal error

# vi wp-config.php
## add this line
define('WP_MEMORY_LIMIT', '64M');

|| links
| google
| wordpress