> For the complete documentation index, see [llms.txt](https://justin-se.gitbook.io/justin-se-docs/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://justin-se.gitbook.io/justin-se-docs/backend/database.md).

# Database

first of all, im not intrested to dive in it deeper, dont expect much from here.

## Mysql

relational database.

* Collation
  * **utf-8**\
    widely use encoding
  * **utf8mb4**\
    full utf-8 character set (including emojis etc)
  * **utf8\_general\_ci**\
    faster index but less accurate encoding
  * **utf8\_unicode\_ci**\
    more accurate for multi language but slower index, example in france "cote", "côte", "coté” will recognize differently, utf8\_general\_ci will mix it up.
  * **utf8mb4\_unicode\_520\_ci**\
    better performance & accuracy than **utf8\_unicode\_ci.**

## MongoDB

document based db, unlike relational database,\
i dont really know much about it.