MongoDB Focus on the Developer Friendliness and being easy to get started with due to its integration with many scripting languages making databases accessibility less cumbersome than compiled language integration. Mongodb is an implementation of a key value store that supports the single value abstraction JSON.
The Oracle Database is a Java based key-value store implementation that supports a value abstraction layer currently implementing Binary and JSON types. It also integrated with various open source technologies like Hadoop/MapReduce.
|DATABASE MODEL||Oracle Database is based on key value data model.||MongoDB’s Data Format is JSON and build an architecture of collection and documents.|
|STORAGE MODEL||Oracle Database storage model is a write ahead logging implementation proven in millions of Berkeley DB deployments.||MongoDB’s default storage system is the Memory-Mapped Storage Engine. It uses memory mapped files for all disk I/O.|
|REPLICATION||Oracle Database supports replication for both availability and scalability. It uses a consistent hashing algorithm over a fixed, highly granular, partition definition.||Mongo manages replication via replicasets, a form of asynchronous master/slave replication. Traditional master/slave replication is available but not recommended.|
|SCALING OUT AND IN||Oracle Database scales out by redistribution of data partitions to newly added hardware resources.||MongoDB relies on sharding for scaling out. It involves designating a certain server to hold certain chunks of the Data as the dataSet grows.|
|CONCURRENCY||The Oracle Database is controlled by the Replicate groups with an elected master. The Reads can be serviced from any node in a replication group and writes are performed at the currently elected master.||MongoDB Relies on the Locks for its consistency.|
|QUERY TYPES AND QUERY ABILITY||Oracle Database provides key access methods like put, get, delete. The database can also be accessed using SQL as an external table from within a relational database.||MongoDB has a query interface that has some similarities to the relational databases, including secondary indexes that can be derived from the stored document|