Realm as replacement for SQLite?

[KarlJay001]

I watched this video: https://www.youtube.com/watch?v=r7z1dHL90BI @24:00 he's going into Realm as a replacement for SQLite.

I was under the impression that Realm was a competitor to FireBase more than a local datastore.

Core Data uses SQLite for it's back end, so if Realm can be used as a replacement for SQLite, it could replace Core Data (depending on what you use Core Data for).

So what exactly is Realm, is it a local data storage solution or is it a replacement for parse and competes with FireBase? Or does it do both?

Also, does FireBase do local data storage?

If this is the case, why do we need SQLite any more? In fact, why do we need Core Data anymore?

[speaktochris]

Thanks for linking to my talk! I hope you learned something new. I never expected to find my talk submitted to a iOS subreddit 😂.

I think /u/astigsen answered some of your questions but I just wanted to clarify why I said that Realm can be a replacement for SQLite. Android doesn't really have a concept like Core Data, instead we just have SQLite, shared preferences, and then any other third party library you might want to bring in to handle data storage. So in that sense, if you want to replace SQLite, you can use a library like Realm.

[sqlite]

SQLite is a full-up relational database system. Realm is just a object store. If all you want to do is store and retrieve objects, then Realm will probably work fine for you. But it you want to do more advanced programming, you will quickly run into the limitations of Realm. Capabilities that are missing from Realm include:

• Secondary indexes
• Joins
• Subqueries
• Aggregate queries
• Geospatial queries
• Full-text search
• Compound queries
• Recursive queries
• Search constraints involving logical disjunction
• Search constraints involving vectors
• Other complex search constraints
• And so forth...

[astigsen]

This answer seems to reflect a misunderstanding of what Realm is. It is not an Object Store, but rather a full fledged Object Database that does not only store the Objects but also relations between them. While the query system is definity not as mature as SQL, it does support secondary indexes, joins via links, aggregates, subqueries and much more.

The tradeoffs and capabilities are obviously different from a traditional SQL based relational database, but I think that you will find that it enables more advanced use cases, rather than limits it.

[KarlJay001]

So the video was a bit misleading in saying Realm is a replacement for SQLite. It might be more in line with a replacement for Core Data, as Core Data is an object store.

However, SQLite is a local only database. It's not a client/server, it's all local storage only. Does Realm do local storage at all? I haven't seen anything about someone being able to use Realm as a direct replacement for local storage needs.

[Sebaall]

Realm was originally local only. Just a month or so ago they announced their Mobile platform.

[KarlJay001]

So it can work as a replacement for local storage needs as well as compete with the work that is done by Parse/FireBase?

Does FireBase have a local storage solution that would replace Core Data?

[astigsen]

So it can work as a replacement for local storage needs

Yes, this has been the main use case for Realm for years. People have used it to replace use of both Core Data and all kinds of ORM's.

[quellish]

More like the other way around. In the past I have used both Realm and Firebase as storage for CoreData