With the development of NoSQL, HBase gradually become the mainstream of the NoSQL system products. The advantages of HBase is very obvious, but defect is also very obvious. These weaknesses include large data platform business by SQL to NoSQL migration is more complex and application personnel learning cost is quite high, can't support affairs and multidimensional index, eventually making many business can't enjoy from NoSQL system linear development ability. Google internal MegaStore system complements Bigtable,it supports SQL, transactions, indexing, cross-cluster replication in the upper layer of the Bigtable, and became famous applications's storage engine, such as Gmail, APPEngine, and the Android Market.
Therefore, we decided to explore providing cross-row transactions, indexes, SQL function without sacrificing the linear expansion of capacity in the upper layer of the HBase by theoretical model MegaStore. The system provides simple user interface: SQL, the user can do not need to pay attention to the hbase schema design, greatly simplifies the user's data migration and learning costs. To see what's supported, go to our language reference guide, and read more on our wiki.
Become a standard distributed relational database,which's storage engine is nosql system, for example the hbase.