Diferenças entre CouchDB e MongoDB (controle de concorrência) Quando se fala de bancos não relacionais, logo se vem dois nomes de peso: CouchDB e MongoDB. Há uma certa dúvida sobre por qual começar, qual é o melhor, qual a diferença entre um e outro. Cheguei a pesquisar alguns artigos e comparativos, e praticamente todas as conclusões que lia era apenas gostos ou contra-gostos. Eu não sei explicar o porquê, mas me parece que o MongoDB caiu no gosto dos que querem começar com NoSQL. Talvez pelo fato de poder enviar queries pela aplicação, e no CouchDB as consultas serem todas em views, totalmente ‘fora’ da aplicação. Não quero alimentar nenhum flame war, o que quero explicar aqui é só uma opinião pessoal que cheguei através de tentativas, testes, e conversas sobre quem estava usando e seus dilemas.
Como conheço mais o CouchDB, posso dizer alguns pontos que se destacam: Replicação tanto no Couch quanto no Mongo são bem simples. Esta é a característica crucial que me faz decidir pelo CouchDB. Traduzindo livremente: Enquanto que… Cassandra vs MongoDB vs CouchDB vs Redis vs Riak vs HBase ... (Yes it's a long title, since people kept asking me to write about this and that too :) I do when it has a point.)
While SQL databases are insanely useful tools, their monopoly in the last decades is coming to an end. And it's just time: I can't even count the things that were forced into relational databases, but never really fitted them. (That being said, relational databases will always be the best for the stuff that has relations.)
But, the differences between NoSQL databases are much bigger than ever was between one SQL database and another. This means that it is a bigger responsibility on software architects to choose the appropriate one for a project right at the beginning. In this light, here is a comparison of Open Source NOSQL databases Cassandra, Mongodb, CouchDB, Redis, Riak, RethinkDB, Couchbase (ex-Membase), Hypertable, ElasticSearch, Accumulo, VoltDB, Kyoto Tycoon, Scalaris, OrientDB, Aerospike, Neo4j and HBase: The most popular ones Redis (V3.2) Cassandra (2.0) MongoDB (3.2) Comparing NoSQL Availability Models.
Let's risk feeding the CAP trolls, and try to get some insight into the differences between the many NoSQL contenders.
I have circulated an earlier version of this to a few people and got at least one good response. If you have answers, or would like to suggest additional questions, comment here, tweet me @adrianco or blog it yourself. Use Case Scenario for Comparison Across NoSQL Contenders While each NoSQL contender has different strengths and will be used for different things, we need a basis for comparison across them, so that we understand the differences in behavior.
Here is a sample scenario that I am publishing to put to each vendor to get their answers and will post the results here. Use CaseA TV based device calls the API to add a movie to its favorites list (like the Netflix instant queue, but I have simplified the concept here), then reads back the entire list to ensure it is showing the current state. Question 4: Handling Silent Data Corruption Question 5: Backup and Restore.