> For the complete documentation index, see [llms.txt](https://note.levelcode.org/software-engineering-notes/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://note.levelcode.org/software-engineering-notes/database.md).

# Database

- [In-Memory (Redis)](https://note.levelcode.org/software-engineering-notes/database/in-memory-redis.md)
- [Search Engine (Elasticsearch)](https://note.levelcode.org/software-engineering-notes/database/search-engine-elasticsearch.md)
- [Column-Oriented (Cassandra)](https://note.levelcode.org/software-engineering-notes/database/column-oriented-cassandra.md)
- [Document-Oriented (MongoDB)](https://note.levelcode.org/software-engineering-notes/database/document-oriented-mongodb.md)