Which datasize is suitable for storing an RFID column in a SQL server?

Question

I am new to the whole RFID arena.

I need to save an RFID resource in a database. It has not yet been decided which system will feed this particular field (or fields?), So I just want to set aside some space right now.

Oracle has the entire Identity package, which handles, among other things, the various versions and types of RFID, but I have not seen anything for the SQL server.

Maybe I’m compromising too much, but I searched broad, but did not find a link to how big such a tag is, or even if it is suitable for storage in one field or if you need several.

So which columns should I have, and what should their sizes be? Would nvarchar (10) be enough? NVARCHAR (20)?

Answer 1

There is no fixed data size for RFID tags. In fact, they can store from a few bytes to a few kilobytes. They can even be used to crack an insecure system by storing code in them. Therefore, you should process any data you receive from them with the same suspicion as elsewhere.

As for the identifier, which is unique, if you select no more than UUIDs based on it, then you should be fine.

Answer 2

AFAIK generation 1 RFID tags are typically 128 bits, where 96 bits are a unique identifier and the rest is a checksum. But I strongly suspect that new generations have at least 256 bits, and it will continue to grow. I am by no means an expert, so you can wait for another answer :)

So, I would go with a char or varchar of sufficient size, which should be easy to scale later.

Answer 3

Unfortunately, the standards in the RFID world at the moment indicate all kinds of useful things, but not the size of the tag (these standards are usually industry specific, and the ability to track cows may not display what you have planned so well).

My advice would be to allocate something enough to store the test data ( nvarchar(10) should be fine), and then configure it correctly when choosing the actual implementation, after which the provider will be able to provide you with this information.

Answer 4

There is no fixed size for RFID tags, but I believe that it is currently worth it (January 2011). 2KB is the maximum size in the HF specification, this includes the tag identifier, user data and data set by the manufacturer necessary for the tag to function. In the UHF specification, instead of unique identifiers, you have an EPC that is edited by the reader if the tag is unlocked, unlike unique identifiers in HF that are set and locked by the manufacturer. At the end of the day, you need to read the data layout for the memory tag that you are using. Manufacturers will provide the necessary technical document that will explain the available memory addresses and, therefore, the maximum size that you need.