What is the difference TEXT and LONGTEXT?

Question

I am developing a system where I will import the data from an Excel. As this data will be temporary, I intend to save the information of this imported column in format JSON at the bank.

Therefore, I was in doubt between using TEXT or LONGTEXT.

Of course this case is just one example, but there are other cases where doubt comes to mind, for example, when saving a blog post in the bank. I’d have to use TEXT or LONGTEXT?

I imagine there’s a difference just because of the names, and not because I know the technical details of the difference between one and the other.

So my question is:

• What’s the difference between LONGTEXT and TEXT?

• Use LONGTEXT would make my bank use more resources than use TEXT?

• There is a difference in reading speed or performance when choosing one or the other?

• In which cases I would have to use LONGTEXT instead of TEXT?

_{NOTE: In fact, I don’t even want anyone to point out in the answer what I should do with this data that I’m importing, but I would just like to know what the difference is between the two types (LONGTEXT and TEXT). Even because I know that the new version of MYSQL has the format JSON, but that’s another story, since I don’t use the new version of MYSQL*.}

Answer 1

In the Documentation you will find a lot about each type, summarizing in Sizes:

      Tipo | Tamanho Máximo
-----------+--------------------------------------
  TINYTEXT |           255 (2^ 8−1) bytes         
      TEXT |        65,535 (2^16−1) bytes = 64 KiB
MEDIUMTEXT |    16,777,215 (2^24−1) bytes = 16 MiB
  LONGTEXT | 4,294,967,295 (2^32−1) bytes =  4 GiB

• What is the difference between LONGTEXT and TEXT? Maximum Memory Allocation (size) as above Table;

• Would using LONGTEXT make my bank use more resources than using TEXT? Exactly, for each line in your Bank it would be necessary to book, clean, validate more memory.

• Is there a difference in reading speed or performance when choosing one or the other? Performance differences are few in small Bases (you practically don’t care about performance on bases with tens or a few hundred results), but they can be very palpable for large Bases (1TB+), so the answer is: yes.
• In which cases would I have to use LONGTEXT instead of TEXT? When storing more than 16Mi Chars. Storing a whole book, or all the information of a RAW image, for example.