Comparing the Hadoop File System (HDFS) with the Cassandra File System (CFS) : DataStax

The Hadoop Distributed File System (HDFS) is one of many different components and projects contained within the community Hadoop™ ecosystem. The Apache Hadoop project defines HDFS as: “the primary storage system used by Hadoop applications. HDFS creates multiple replicas of data blocks and distributes them on compute nodes throughout a cluster to enable reliable, extremely …


Scaling Distributed Counters | WhyNosql

Distributed counters is an important functionality many distributed databases offer. For an ad network distributed counters are important for many reasons. Real time ad impressions and click data can be used for ad optimization. HBase and Cassandra both support distributed counters. via Scaling Distributed Counters | WhyNosql.

Aggregation — MongoDB Manual 2.4.9

Aggregations operations process data records and return computed results. Aggregation operations group values from multiple documents together, and can perform a variety of operations on the grouped data to return a single result. MongoDB provides three ways to perform aggregation: the aggregation pipeline, the map-reduce function, and single purpose aggregation methods and commands. via Aggregation …


Cassandra vs MongoDB vs CouchDB vs Redis vs Riak vs HBase vs Couchbase vs Hypertable vs ElasticSearch vs Accumulo vs VoltDB vs Scalaris comparison :: Software architect Kristof Kovacs

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. via Cassandra vs MongoDB vs CouchDB vs Redis vs Riak vs HBase vs Couchbase …