**Key-Value stores, document databases, graphs, and other NoSQL database types.** # Key-Value Store Literally just a big collection of key-value pairs. Keys appear just once per database. # Document Store Stores of [[JSON]], [[YAML]], or [[XML]]. These are highly flexible. # [[Graph Database]] Sets of edges and nodes. Allowing for highly-linked data. In graphs, the relationships between nodes are themselves capable of holding information. Graphs allow for semantic queries, where you can specify things like "show me all the liked posts by friends of my friends" naturally. ## Triple Store Triplestores are a type of [[Graph Database]] that store [[Subject-Predicate-Object|Semantic Triple]]s, which are datasets of the form "[[Subject-Predicate-Object]]", like "Man has ball", or "Aaron married Melissa". ## Named Graph Named graphs are extended Triplestores, with a fourth dimension specifying their context. They are of the basic form "Subject-Predicate-Object-Context". These can also be called “quadstores”. **** ## Source - [NoSQL - Wikipedia](https://en.wikipedia.org/wiki/NoSQL) ## Related - [[Relational Databases]] - [[Non-Relational Databases]]