Digitalization is still on the rise, and so is the number of digital devices (from 15 billion mobile devices operating + 13 billion connected IoT devices in 2021 already). Due to this, data volumes grow accordingly (estimated 79 zettabytes of data created in 2021), and centralised computing can no longer support the current needs. This has led to new challenges in computing and subsequently is leading to a shift from the cloud to the edge.

Consequently, the Edge Computing market is expected to grow by 14.8% in 2022 and the years to come (IDC 2022). Hence, there is an increased need for data persistence on the edge. Data flows to / from and between edge devices can be done with Edge Databases and Data Sync. For this reason, we have a look at the edge database market in the following review.

Databases

While being quite established and somewhat saturated, the database market is still growing consistently and significantly. The reason is that databases are at the core of almost any digital solution, and therefore never out of fashion. With the rapid evolvements in the tech industry, however, databases need to evolve too. This, in turn, yields new database types and categories. We have seen the rise of NoSQL databases in the last 20 years, and more recently some novel database technologies, like graph databases and time-series databases. Both the shift from a centralised towards a decentralised paradigm and the growing number of restricted devices call for a new type of database. Thus, we expect Edge databases to become more prominent in the coming years.

What are the advantages and disadvantages of working with SQLite?

SQLite is a relational database that is clearly the most established database suitable to run on edge devices. Moreover, it is probably the only “established” mobile database. It was designed in 2000 by Richard Hipp and has been embedded with iOS and Android since the beginning. Now let’s have a quick look at its main advantages and disadvantages:

What are the SQLite alternatives?

There are a bunch of options for making your life easier, if you want to use SQLite. You can use an object abstraction on top of it (ORM), for instance greenDAO, to avoid writing lots of SQL. However, you will typically still need to learn SQL and SQLite at some point. So what you really want is a full blown database alternative, like any of these: Couchbase Lite, Interbase, LevelDB, ObjectBox, Oracle Berkeley DB, Mongo Realm, SnappyDB, SQL Anywhere, or UnQLite.

While SQLite really is designed for small devices, people do run it on the server / cloud too. However, for server / cloud databases, there are a lot of alternatives you can use as a replacement like e.g. MySQL, MongoDB, or Cloud Firestore.

Bear in mind that, if you are looking to host your database centrally with apps running on small distributed devices (e.g. mobile apps, IoT apps, any apps on embedded devices etc.), there are some difficulties. Firstly, this will result in higher latency, i.e. slow response-rates. Secondly, the offline capabilities will be highly limited or absent. As a result, you might have to deal with increased networking costs, which is not only reflected in dollars, but also CO2 emissions. On top, it means all the data from all the different app users is stored in one central place. This means that any kind of data breach will affect all your and your users’ data. Most importantly, you will likely be giving your cloud / database provider rights to that data. (Consider reading the general terms diligently). If you care about privacy and data ownership, you might therefore want to consider an Edge Database. This way you can limit what data you sync to a central instance (like the cloud). 

SQLite alternatives Comparison Matrix

To give you an overview, we have compiled a comparison table including SQLite and SQLite alternatives. In this matrix we look at databases that we believe are apt to run on edge devices. Our rule of thumb is the databases’ ability to run on Raspberry Pi type size of devices.

Star this matrix on GitHub. If you are interested in an indication of the diffusion rate of databases and mobile databases, check out the following database popularity ranking: http://db-engines.com/en/ran.

Is there anything we’ve missed? What do you agree and disagree with? Please share your thoughts with us via Twitter or email us on contact[at]objectbox.io. 

Make sure to check out the ObjectBox Database & try out ObjectBox Sync. You can get started in minutes. More than 1,000,000 developers already use this Edge Database designed specifically for high performance on embedded devices.