When to use CouchDB over MongoDB and vice versa

Question

I am stuck between these two NoSQL databases.

In my project I will be creating a database within a database. For example, I need a solution to create dynamic tables.

So users can create tables with columns and rows. I think either MongoDB or CouchDB will be good for this, but I am not sure which one. I will also need efficient paging as well.

Answer 1

Of C, A & P (Consistency, Availability & Partition tolerance) which 2 are more important to you? Quick reference, the Visual Guide To NoSQL Systems

• MongodB : Consistency and Partition Tolerance
• CouchDB : Availability and Partition Tolerance

A blog post, Cassandra vs MongoDB vs CouchDB vs Redis vs Riak vs HBase vs Membase vs Neo4j comparison has 'Best used' scenarios for each NoSQL database compared. Quoting the link,

• MongoDB: If you need dynamic queries. If you prefer to define indexes, not map/reduce functions. If you need good performance on a big DB. If you wanted CouchDB, but your data changes too much, filling up disks.
• CouchDB : For accumulating, occasionally changing data, on which pre-defined queries are to be run. Places where versioning is important.

A recent (Feb 2012) and more comprehensive comparison by Riyad Kalla,

• MongoDB : Master-Slave Replication ONLY
• CouchDB : Master-Master Replication

A blog post (Oct 2011) by someone who tried both, A MongoDB Guy Learns CouchDB commented on the CouchDB's paging being not as useful.

A dated (Jun 2009) benchmark by Kristina Chodorow (part of team behind MongoDB),

I'd go for MongoDB.

Hope it helps.