On Providing DDL Support for a Relational Layer over a Document NoSQL Database

Abstract

NoSQL databases are gaining ground due to the need for several applications to manipulate large volumes of data without worrying about database system tuning and scaling. However, many applications still use relational databases and do not want to replace their access methods in order to properly manipulate their data on the cloud using now a NoSQL technology. To deal with this problem, a relational-cloud mapping strategy, in terms of data model and data operations, is able to provide a relational view of NoSQL data, eliminating the need for adjustments in the application interface for data management. SimpleSQL is a solution for this problematic. It is a relational layer for Amazon SimpleDB, one of the most popular document NoSQL databases. Although SimpleSQL had proved to be a promising approach in terms of performance, its current version provides only the mapping of SQL DML operations. This paper presents an extension of SimpleSQL to support also DDL operations. This extension allows the creation and manipulation of the database schema from the application (client) side, abstracting any knowledge about data definition at SimpleDB. Preliminary experiments show that our solution continues to be feasible, since the overhead with DDL operations through SimpleSQL is not prohibitive.