💾 SQLlite

SQLlite is:

• Open Source: read free.
• Well-established: has been maintained forever.
• Serverless: doesn't have a separate server process, just install a library to use.
• Self-contained: the actual database is a single file.
• Uses SQL Syntax: implements the most of SQL-92 standard so normal queries work.
• Portable: Runs virtually anywhere with a file system.

When not to use SQLlite:

1. Database and the application communicate over a network. Client-Server databases make more sense in this case.
2. You have many concurrent writers. SQLlite supports having a single concurrent writer by design. Multiple applications reading it is totally fine though.
3. You have more than 1TB of expected data. SQLlite does support up to 281TB but it does slow down after the 1TB. 99% of the time, you won't have this much data incoming.