I'm having trouble with a MySQL function I pulled across from another db. I did and import of the data and the functions and procedures separately.
I now have a makehash function that makes a call to preg_replace. I can't see this function or procedure anywhere though. 
If I run show function status or show procedure status nothing to do with preg_replace shows up, only the custom procedures and functions that were there before.
Is there something I am missing that is installed on the db I copied from that I have neglected to copy over to the new one?
Here is the makehash function:
CREATE DEFINER=`root`@`localhost` FUNCTION `makehash`(description text, raw_location text, title text) RETURNS varchar(32) CHARSET utf8
NO SQL
DETERMINISTIC
begin
    declare data longtext;
    declare hash varchar(32);
    set data = ifnull(description, '');
    set hash = null;
    if length(data) > 64 then
        set data = lower(concat(data, ifnull(raw_location, ''), ifnull(title, '')));
        set hash = md5(preg_replace('/[^a-z]/', '', data));
    end if;
return hash;
 
    