So many questions need to be asked and answered, preferably in the form of a Functional Specification, before your specific question can be answered. As a systems architect, I use a formal process to shake out the business requirements, functional requirements (short and long term), security requirements (sensitivity of data, enforcement of IT security policies, legal etc. l), reliability, and other analysis. I read your problem as a matter of data synchronization between a mobile device and a centralized database.
If your data is not relational as it needs to be manipulated on the mobile device (regardless of the structure of data on the server), IndexDB is perfectly fine and comes for free in any web browser or web view. Then you need not even develop using Cordova plugin (or such). I’ve built a very sophisticated enterprise system with mobile app data synchronization using IndexDB for local storage on the device. The server runs a REST service for synchronization to back end persistence layer, mediated through a business tier. And the REST API for the mobile device is just an information model exchange interface. The back end implementation representation data, whether in a relational database, NoSQL, etc. should not be exposed in the client API. It makes your linkage between the client and the server brittle.