The current digital ecosystem produces a vast volume of data, which is generated across various domains, including astronomy, healthcare, e-commerce, social media, over-the-top content platforms, etc. In many healthcare institutions and organizations, a tremendous amount of diverse and heterogeneous data is generated annually. These data comprise a wide and diverse variety of electronic and paper-based medical records in structured, semi-structured, and unstructured formats. This paper presents a comprehensive study and rigorous analysis of polyglot persistence-based systems that leverage multiple datastores to integrate, query, and store diverse and heterogeneous data across various domains, including an in-depth examination of datasets, approaches, procedures, results, and challenges. To unify these diverse data horizons and enable functional synergy, this paper proposes a polyglot persistence-based system to demonstrate healthcare information on the Multiparameter Intelligent Monitoring in Intensive Care II (MIMIC-II) dataset, motivated by the need to combine the strengths of both relational databases and NoSQL data stores. The system comprises a user interface, a security layer, a mediator, and multiple datastores. The snippets of the implementation have been presented, and the results demonstrate effective data unification of tabular, document, and key-value data, as well as the vast capability of querying within a single system framework.