From Document Warehouse to Column-Oriented NoSQL Document Warehouse

NoSQL (Not only SQL) gathers recent solutions that differ from the SQL model by a different logic of data representation. It is characterized by its performance and its ability to handle a large amount of data. Due to the absence of a clear approach to implement a Document Warehouse (DocW) under NoSQL model, we propose, in this paper, a set of rules to transform the multidimensional galaxy model of the DocW into the column-oriented NoSQL model. We suggest two types of transformations namely Simple and Hierarchical. In order to validate our proposed transformation rules, we have used Cassandra as a Column-oriented NoSQL system to implement a DocW for each type of transformation. We used Talend Data Integration tool to load data in the implemented DocWs. We evaluate these two DocWs with two metrics WRL (Write Request Latency) and RRL (Read Request Latency) using a medical collection.