Difference between MapR-DB and Hbase

They are both NOSQL, wide column stores.

HBase is open source and can be installed as a part of a Hadoop installation.

MapR-DB is a proprietary (not open source) NOSQL database that MapR offers. A core difference that MapR will detail with MapR-DB (along with their file system (they do not use HDFS)) is that MapR-DB offers significant performance and scalability over HBase (unlimited tables, columns, re-architecture to name a few).

MapR maintains that you can use MapR-DB or HBase interchangeably. I suggest testing on both extensively before committing to one vs the other. You also need to realize that MapR-DB is MapR's proprietary NOSQL HBase equivalent and if you require support for MapR-DB you'll have to get that from MapR (HBase support can come from any of the other Hadoop distributions as well as the open source community).

Some links you should look at:http://www.theregister.co.uk/2013/05/01/mapr_hadoop_m7_edition_solr/https://www.mapr.com/blog/get-real-hadoop-enterprise-grade-nosql#.VVfHuvlVhBc

They are similar but not same. MapR claims that MapR DB is faster and more efficient as they have migrated the critical functionality in native C/C++ code and interface is kept the same. But end of the day MapR DB is propriatory and you depend on the support of MapR for any thing which is done differently than HBase. I didn't liked MapR-DB because it's not compatible with Apache Phoenix(HBase coprocessors are not present in MapR DB) - the SQL way of accessing HBase kind of NoSQL databases.Limitations that i have taken from MapR documentation:

• Custom HBase filters are not supported.
• User permissions for column families are not supported. Userpermissions for tables and columns are supported.
• HBase authentication is not supported.
• HBase replication is handled with Mirror Volumes.
• Bulk loads using the HFiles workaround are not supported and notnecessary. HBase coprocessors are not supported.
• Filters use a different regular expression library
  • Co processors are not supported

So i second previous answer - try out your solution in both(MapR DB vs HBase) before going too far. I didn't liked to very idea of MapR DB from MapR as it's propitiatory and the code is not open source. If any Hadoop distributor is enhancing hadoop - they should also make it available to open source community. Why one should totally rely on commercial support when using opensource.