![]() ![]() If you're interested in previous discussions, look into #350 Store binary UUID in MySQL and #645 Add support for optimized binary UUID keys. While doing this, I discovered that about half our UUIDs are v1, and the other half are v4. This means that the storage requirements are different - a CHAR always takes the same amount of space regardless of what you store, whereas the storage requirements for a VARCHAR vary depending on the specific string stored. I was recently asked to add a column to this table of VARCHAR(32) that stores the non-dashed UUID hex. A CHAR field is a fixed length, and VARCHAR is a variable length field. ![]() That means compressing the 32 characters (36 or more with separators) to the 16-bit format or back to the human-readable format. They are stored in the standard VARBINARY(16). These function will be used to convert from the human-readable format (char/varchar) to the compact format (binary) and back. Here, We will use UUID and UUIDTOBIN() functions to assign the value in OrderId Column. If it's important to you to store uuids in a natively uuid-ish way, switch to a data storage that supports it (postgresql comes to mind.) I have a MySQL InnoDB table with tens of millions of rows. CREATE TABLE OrderDetails( OrderId BINARY(16) PRIMARY KEY, ProductName VARCHAR(100) NOT NULL, Price DECIMAL(10, 2) NOT NULL, ExpectedDelivery DATE NOT NULL ) Now, inserting data into OrderDetails table. The problem here is that mysql, 2019, still don't have an uuid data type. I often come across columns that are varchar (255), so presumably this is a convention of sorts. So, this suggestion would basically break existing non-mysql systems that has a proper uuid type, while forcing everyone into a binary format they need different sql functions to work with. 11 This question already has answers here : MySQL - varchar length and performance (2 answers) Closed 4 years ago. It is designed in such a way that it generates a number which is unique globally according to space and time. ![]() I can't seem to find where that's documented anymore, however. A char(36) or varchar(36) would use 36 bytes. The only way to support this on databases without the proper data type is to store them as something that work identically which in this case becomes string values. A UUID is a Universal Unique Identifier specified by RFC 4122 (It is a Universally Unique Identifier URN Namespace) and 128-bit long value. As far as I'm aware, the UUID type uses 16 bytes, basically storing the UUID as what it is: a 128-bit integer. This means that these databases support syntax like WHERE id = '33555c1f-2211-4a7d-9f66-35cf5413444e' natively, and you can copy/paste those queries around and they will continue to work since they are conforming to the sql standard. Many other databases has a proper uuid type, like postgresql has the uuid type, and SQL Server has a guid type. you really need them because of generating unique ids from different places (and have not figured out another way to do it). I think the recommended/best practices to storing uuid in rdbms is by using binary(16) Generalization: The inefficiency applies to any 'random' access - UUID / MD5 / RAND () / etc. I would like to add another view this isn't as much as if Laravel knows how the column is persisted, but that it breaks compatibility with other systems, including existing raw/manual queries. ![]()
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