Firebase realtime database vs Cloud Firestore for my app

Among other factors, the ones mentioned below are really important when choosing a Database Management System are:

Data Model, Data consistency, Data Security, Data Protection, Multi Access and Integration, Efficiency, Usability, Implementation and Service Costs.

• From Firebase documentation:

Which database is right for your project?

We recommend Cloud Firestore for most developers starting a new project. Cloud Firestore offers additional functionality, performance, and scalability on an infrastructure designed to support more powerful features in future releases. Expect to see new query types, more robust security rules, and improvements to performance among the advanced features planned for Cloud Firestore.

Using Cloud Firestore and Realtime Database

You can use both databases within the same Firebase app or project. Both NoSQL databases can store the same types of data and the client libraries work in a similar manner.

Please note that in the link above you shall find detailed information about the differencies between the two.

• From medium.com:

Cloud Firestore vs. Firebase Realtime Database

Things they have in common:

1. They are both easy to integrate into a project with limited setup, and they are compatible with everything else offered by Firebase. Administrators will be able to see the data through the Firebase console, which uses the same scheme in both of them. What this means is that you can scour through the nodes and collections of the top level to find the data or information that you are looking for.
2. Beyond that, they do not offer any further level of exploration. If you know the keys and objects that you are looking for, this will be useful.

Let’s take a look at the differences.

1. Querying Support — Firestore is more potent in this regard. Locate records that match several field comparisons. Firebase uses a simplistic data structure, which means that you will only be able to run queries that search for the field beginning with your query.
2. Importing and Exporting Data — This is a feature that Firebase provides. It comes in handy when you are migrating data or if team members who are not developers to make some changes to the data.
3. Real-time updates — Firebase focuses on real-time updates, which are very useful for handling customers who are using social media or collaborative apps. It gives developers everything they need to determine the customers that are active users in real-time.
4. Costs — The costs of the Realtime Database will go up as you send more data via reading/write operations. The price of the Firestore database will increase with every API call that you make. However, be sure to look at the entire cost breakdown before making any decisions.

Pricing

In the following link there are detailed information about Firebase Realtime Database Pricing and Cloud Firestore Pricing

You may also find this article useful:

Cloud Firestore vs the Realtime Database: Which one do I use?

Realtime Database is the Firebase’s first and original cloud-based database. For the mobile apps requiring synced states across clients in realtime, it is an efficient and low-latency solution.

Cloud Firestore is Firebase’s newest flagship database for mobile apps. It is a successor to the Realtime Database with a new and more intuitive data model. Cloud Firestore is richer, faster, and more scalable than the Realtime Database.

You should check the official docs. And get a proper idea between these two. There are things you need to consider before choosing either of them. According to your goal, both will help you in different ways.

Realtime and offline support, Querying, Writes and transactions, Reliability and Performance, Scalability, Security, Pricing, Data Model, etc.

These are the things you need to consider while choosing either of these

I would like to suggest this link though.

Cloud Firestore vs the Realtime Database: Which one do I use?

You should think more carefully the future work load your environment will have. That will give you better ground to evaluate the pricing. In general, I would prefer to use Firestore because it is the new one and it is superior when it comes to scaling the service. It will scale automatically as your user base grows and will not need any sharding in high volumes.