NoSQL databases
Compared to their relational cousins, NoSQL databases are more scalable and provide superior performance, and their data model(s) address several issues that the relational model was not designed for when dealing with large volumes of structured, semi-structured, and unstructured data.
They have become important with the rise in the use of “big data,” in dealing with data from the internet, online purchases and other credit card transactions, and so on.
The different types of NoSQL databases can roughly be classified under the following headings, although no taxonomy is perfect:
- Key-value (KV): These are among the simplest NoSQL databases. Every single item in the database is stored as an attribute name (or “key”), along with its value.
- Document: These pair each key with a complex data structure known as a the document, which may contain many different KV pairs, key-array pairs, or even nested documents.
- Columnar...
