Schema Extraction on Semi-structured Data
This survey helps data managers choose appropriate schema extraction techniques for semi-structured data in NoSQL databases, addressing a growing need due to the increasing adoption of NoSQL.
This survey investigates structural methods (tree/graph-based) and statistical methods (distributed architecture/machine learning-based) for schema extraction from semi-structured data in NoSQL databases. It finds that structural methods offer better interpretability, while statistical methods provide superior applicability and generalization.
With the continuous development of NoSQL databases, more and more developers choose to use semi-structured data for development and data management, which puts forward requirements for schema management of semi-structured data stored in NoSQL databases. Schema extraction plays an important role in understanding schemas, optimizing queries, and validating data consistency. Therefore, in this survey we investigate structural methods based on tree and graph and statistical methods based on distributed architecture and machine learning to extract schemas. The schemas obtained by the structural methods are more interpretable, and the statistical methods have better applicability and generalization ability. Moreover, we also investigate tools and systems for schemas extraction. Schema extraction tools are mainly used for spark or NoSQL databases, and are suitable for small datasets or simple application environments. The system mainly focuses on the extraction and management of schemas in large data sets and complex application scenarios. Furthermore, we also compare these techniques to facilitate data managers' choice.