6 Key-value Stores and Document Databases
This chapter covers key-value stores and document databases. Key-value stores are specialized for the efficient storage of simple key-value pairs. Parallel processing of key-value pairs has been popularized with the Map-Reduce paradigm. The Java Script Object Notation (JSON) is a textual format of nested key-value pairs. Document databases use JSON as their main data format. Last but not least, JSON is often used as a format for payload data in REST-based APIs.
6.1 Key-Value Storage
A key-value pair is a tuple of two strings [angbracketleft]key, value[angbracketright]. A key-value store stores such key-value pairs. The key is the identifier and has to be unique. You can retrieve a value from the store ...