History[04]

Realm originates from the project called TightDB which was initially developed by Alexander Stigsen and Bjarne Christiansen began in the end of 2010. The first version of Realm was released in June 2016 and a platform for real-time two-way synchronization in beta version was released in 2016 September.

Checkpoints

Not Supported

Compression

Not supported

Concurrency Control[05]

In Realm, each connected thread will see a snapshot of the data at a particular point in time. Moreover, it utilizes the copy-on-write mechanism and allows only one client to modify data at a certain point.

Data Model

Foreign Keys

Not Supported

Hardware Acceleration

No Acceleration

Indexes[06]

Realm is based on B- Tree Structure

Isolation Levels[05]

No objects shared between threads, which means it's literally single-thread.

Joins

It's not relational database

Logging[07]

Realm only maintains the log for the transaction. But it doesn't support the recovery mechanism.

Query Compilation

Query Interface

Realm Database has its own custom APIs.

Storage Architecture[08]

You could configure during run-time.

Storage Model[09]

Properties would be kept contiguously linked at the vertical level.

Storage Organization[09]

Stored Procedures

System Architecture

Realm Database is not a distributed database. It's mainly for the mobile device.

Views

Realm database supports reflective views and imperative views. Essentially they are very similar to materialized views and virtual views.