… the problem. What is about Secondary Keys ? For Innodb tables UUID have extremely poor impact on your secondary key because all… set is large auto_increment would work much better than UUID because UUID will have recent data scattered all across. Lookups Later… 200 times performance difference which is worth to consider Can UUID be handled efficiently ? They would not be as efficient as…

… FUNCTION ENCODE_UUID (uuid CHAR(36)) RETURNS BINARY(16) DETERMINISTIC BEGIN RETURN REVERSE(UNHEX(REPLACE(uuid, ‘-’,”))); END $$ DELIMITER $$ CREATE FUNCTION DECODE_UUID (uuid BINARY(16…(uuid),5,2)),’-', HEX(MID(REVERSE(uuid),7,2)),’-', HEX(MID(REVERSE(uuid),9,2)),’-', HEX(RIGHT(REVERSE(uuid),6)) ); END $$ SELECT DECODE_UUID(ENCODE_UUID…

… you already “know” when you store it. Portions of the UUID never change when generated on the same server, so if…: $uuid = substr($uuid, 0, . substr($uuid, 9, 4) . substr($uuid, 14, 4) . substr($uuid, 19, 4); where $uuid is the result of doing a SELECT UUID…

… MySQL when stored as text. Ideally, MySQL would have a UUID column type to store the values as binary rather than… improve the situation, I created a simple UUID class capable of generating random UUID‘s with an option to store them in… conversion and come up with a case-sensitive 22-byte UUID representation (VTIW7xOgReOGrL3vMRjm4Q, for example). The performance increase was enormous, and…

…. First simply SELECT REVERSE(UNHEX(REPLACE(UUID(),’-',”))); this will give us the UNHEXed and REVERSEd UUID in the way that Jens Wagner… the database later, you call SELECT HEX(REVERSE(‘{$uuid}’)); And to make the UUID look more “natural,” simply run strtolower() to remove…

… ascii representation of a binary number when in fact the UUID should have bin stored in binary form. This is equivalent… persons First, Middle and Last name to search for the UUID implementation. Write a function that converts the value returned by… you need to display it. However, the primary use for UUIDs or GUIDs is data portability, not speed for searching. If…

… pseudo-random) values. A reason you would want to use UUID/GUID over auto incrementing integers is when you’re synchronizing… constantly updating IDs on record inserts during synchronization. If the UUID() values were random (like a Guid in .NET) there should… chance of collisions. I would also like to see a UUID data type (which would use 16-byte binary representation instead…