Data Abstraction Levels
In this section, from the final corpus selected, we analyzed the proposed data abstraction levels, the models presented at the conceptual, logical and physical levels, the proposed approaches for transformation between abstraction levels, the modeling language, methodology and tools.
For this concept, we intend to determine what levels of data abstraction have been covered by the studies for data modeling solutions. As mentioned in the Big Data Concepts subsection, there are three levels used for relational databases that are also used in NoSQL stores: conceptual, logical and physical. According to Figure 10, which summarizes the data obtained in Appendix A from the 36 studies, 25 present approaches for data modeling at the three levels of abstraction, therefore, those studies can be considered as complete works that reached the physical implementation of their proposals in a NoSQL storage. The other studies only cover one or two levels although it is possible that, in the future, their works will demonstrate their approaches at all three levels.
