# Welcome to Datahike Tuts > **Disclaimer**\ > This guide is not going to be very formal and is being written as I learn so might not all have the best flow. I may circle back at some point and fix the flow. No promises though. ### Why? I've wanted to use an immutable database powered by datalog for ages. Eventually I decided to do something about [it](https://twitter.com/alekcz/status/1285111415955697664). ![How it all began](https://1725846247-files.gitbook.io/~/files/v0/b/gitbook-legacy-files/o/assets%2F-MCl1SVElOPyxva9PltW%2F-MCl8vw-ax6m2YqARoho%2F-MCl9hbBgYCL3HOwjfyI%2Forigins.png?alt=media\&token=2bbf6452-19b8-4694-88bc-a4c8d41f190b) ### What we'll be using * Clojure through [leiningen](https://leiningen.org/) * [Datahike](https://github.com/replikativ/datahike) by wonderful folks at [replikativ](https://replikativ.io/) * The REPL You can get started by cloning this [repo](https://github.com/alekcz/datahike-starter) I put together. It's nothing special. It just has all the dependencies, nothing special. The most popular open source datalog engine for clojure is [tonksy/datascript](https://github.com/replikativ/datahike). It's been built from the ground up and is use quite extensively in [datahike](https://github.com/replikativ/datahike). ### Understanding datalog [@pithyless](https://twitter.com/pithyless) has a great video introducing datalog. {% embed url="" %} ### Now let's add the magic. Datahike is an immutable database powered by an efficient datalog query engine. It started out as as a port of [DataScript](https://github.com/tonsky/DataScript) to the [hitchhiker-tree](https://github.com/datacrypt-project/hitchhiker-tree). But what is a hitchhiker tree? {% embed url="" %} ### Cheers I think that's enough for today. I'll catch you on the morrow.