1.8 KiB
1.8 KiB
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NoSQL
NoSQL introduction
NoSQL is a collection of data items represented in a key-value store, document-store, wide column store, or a graph database. Data is denormalized, and joins are generally done in the application code. Most NoSQL stores lack true ACID transactions and favor eventual consistency .
NoSQL under BASE principle
BASE is often used to describe the properties of NoSQL databases. In comparison with the CAP Theorem , BASE chooses availability over consistency.
- Basically available - the system guarantees availability.
- Soft state - the state of the system may change over time, even without input.
- Eventual consistency - the system will become consistent over a period of time, given that the system doesn't receive input during that period.
In addition to choosing between SQL or NoSQL , it is helpful to understand which type of NoSQL database best fits your use case(s) . We'll review key-value stores, document-stores, wide column stores, and graph databases in the next section.