Since we live in an imperfect world where we often have to trade ease-of-use for simplicity and abstractions for performance, while dealing with computer systems and standards you’ll often run into tasks that seem like they should be really obvious and simple only to later discover that in reality they lead down a rabbit hole. Such is the case anytime a developer comes into contact with the individual bits of a binary blob – and that can happen even when you least expect it.
The premise is simple: given a database powered by, for example, the extremely popular MySQL or SQLite RDBMS engines that do not offer “native” representation of UUIDs or GUIDs, database designers and systems programmers have a choice to make: do you store a GUID as a plaintext (VARCHAR or TEXT) and take the performance, memory, and storage hit that comes with it, or do you take off the gloves and dig out the BLOB column type in your DDL?