Nine things you must know about nosql)

The list mentioned in this article comes from Article The article is titled nosql knowledge that users of relational databases must know. The difference between the nine-point nosql and RDBMS is very good. Nosqlfan is translated here.

Nosql dB basics for the RDBMS-SAVVY

1. Understand the differences between acid and base (acid is the four requirements for strong consistency of relational databases, while base is the weak requirement principle of nosql databases for availability and consistency. They mean, acid: atomicity, consistency, isolation, durability; base: basically available, soft-state, eventually consistent. What's interesting is that acid stands for acid in English, and base stands for alkali)

2. Understand the difference between persistence and non-persistence. This is because some nosql systems use pure memory storage.

3. You must be aware of the essential differences between traditional relational databases and nosql systems in data structures. Traditional relational databases are usually row-based table store, while nosql systems include columns-based storage (Cassandra), key/value storage (memcached), and document-based storage (couchdb) and graph structure storage (neo4j)

4. Unlike traditional relational databases, which have unified SQL language operation interfaces, nosql systems usually have their own unique API interfaces.

5. In terms of architecture, you must understand that the nosql system is designed for use in clusters with hundreds of machines, rather than shared database systems.

6. In a nosql system, you may have to get used to situations where your data exists.

7. In a nosql system, you 'd better get used to its weak consistency ." Eventually consistent is an important part of the base principle. For example, on Twitter, you often feel the data delay in the followers list.

8. In nosql systems, you need to understand that data is not always available in many cases.

9. You have to understand that some solutions are partition-tolerant and some may not.

Source: http://blog.nosqlfan.com/html/1535.html