by Angela Guess
Andrew Oliver of InfoWorld has written a helpful guide for choosing the best NoSQL solution for your needs. Oliver writes, “Part of the reason there are so many different types of NoSQL databases lies in the CAP theorem, aka Brewer’s Theorem. The CAP theorem states you can provide only two out of the following three characteristics: consistency, availability, and partition tolerance. Different datasets and different runtime rules cause you to make different trade-offs. Different database technologies focus on different trade-offs. The complexity of the data and the scalability of the system also come into play.”
He continues, “Relational databases are based on relational algebra, which is more or less an outgrowth of set theory. Relationships based on set theory are effective for many datasets, but where parent-child or distance of relationships are required, set theory isn’t very effective. You may need graph theory to efficiently design a data solution. In other words, relational databases are overkill for data that can be effectively used as key-value pairs and underkill for data that needs more context. Overkill costs you scalability; underkill costs you performance.”
