course-info

GitHub Repo for http://dsg.csail.mit.edu/6.830/

We will be using git, a source code control tool, to distribute labs in 6.814/6.830. This will allow you to

incrementally download the code for the labs, and for us to push any hot fixes that might be necessary.

You will also be able to use git to commit and backup your progress on the labs as you go. Course git repositories will

be hosted as a repository in GitHub. GitHub is a website that hosts runs git servers for thousands of open source

projects. In our case, your code will be in a private repository that is visible only to you and course staff.`

This document describes what you need to do to get started with git, and also download and upload 6.830/6.814 labs via

GitHub.

- [Learning Git](#learning-git)

- [Setting up GitHub](#setting-up-github)

- [Installing Git](#installing-git)

- [Setting up Git](#setting-up-git)

- [Getting Newly Released Labs](#getting-newly-released-lab)

- [Word of Caution](#word-of-caution)

- [Help!](#help)

There are numerous guides on using Git that are available. They range from being interactive to just text-based. Find

one that works and experiment; making mistakes and fixing them is a great way to learn. Here is a link to resources that

GitHub suggests:

[https://help.github.com/articles/what-are-other-good-resources-for-learning-git-and-github][resources].

If you have no experience with git, you may find the following web-based tutorial

helpful: [Try Git](https://try.github.io/levels/1/challenges/1).

Now that you have a basic understanding of Git, it's time to get started with GitHub.

0. Install git. (See below for suggestions).

1. If you don't already have an account, sign up for one here: [https://github.com/join][join].

The instructions are tested on bash/linux environments. Installing git should be a simple `apt-get / yum / etc install`.

Instructions for installing git on Linux, OSX, or Windows can be found at

[GitBook:

Installing](http://git-scm.com/book/en/Getting-Started-Installing-Git).

If you are using Eclipse/IntelliJ, many versions come with git configured. The instructions will be slightly different than the

command line instructions listed but will work for any OS. Detailed instructions can be found

at [EGit User Guide](http://wiki.eclipse.org/EGit/User_Guide)

, [EGit Tutorial](http://eclipsesource.com/blogs/tutorials/egit-tutorial), or

[IntelliJ Help](https://www.jetbrains.com/help/idea/version-control-integration.html).

You should have Git installed from the previous section.

1. The first thing we have to do is to clone the current lab repository by issuing the following commands on the command

line:

```bash

$ git clone https://github.com/MIT-DB-Class/simple-db-hw-2021.git

```

Now, every time a new lab or patch is released, you can

```bash

$ git pull

```

to get the latest.

That's it. You can start working on the labs! That said, we strongly encourage you to use git for more than just

downloading the labs. In the rest of the guide we will walk you through on how to use git for version-control

during your own development.

2. Notice that you are cloning from our repo, which means that it will be inappropriate for you to push your code to it.

If you want to use git for version control, you will need to create your own repo to write your changes to. Do so

by clicking 'New' on the left in github, and make sure to choose **Private** when creating, so others cannot see your

code! Now we are going to change the repo we just checked out to point to your personal repository.

3. By default the remote called `origin` is set to the location that you cloned the repository from. You should see the following:

```bash

$ git remote -v

origin https://github.com/MIT-DB-Class/simple-db-hw-2021.git (fetch)

origin https://github.com/MIT-DB-Class/simple-db-hw-2021.git (push)

```

We don't want that remote to be the origin. Instead, we want to change it to point to your repository. To do that, issue the following command:

```bash

$ git remote rename origin upstream

```

And now you should see the following:

```bash

$ git remote -v

upstream https://github.com/MIT-DB-Class/simple-db-hw-2021.git (fetch)

upstream https://github.com/MIT-DB-Class/simple-db-hw-2021.git (push)

```

4. Lastly we need to give your repository a new `origin` since it is lacking one. Issue the following command, substituting your athena username:

```bash

$ git remote add origin https://github.com/[your-repo]

```

If you have an error that looks like the following:

```

```

Or this error:

```

```

This appears to happen to some depending on the version of Git they are using. To fix it, just issue the following command:

```bash

$ git remote set-url origin https://github.com/[your-repo]

```

This solution was found from [StackOverflow](http://stackoverflow.com/a/2432799) thanks to [Cassidy Williams](https://github.com/cassidoo).

For reference, your final `git remote -v` should look like following when it's setup correctly:

```bash

$ git remote -v

upstream https://github.com/MIT-DB-Class/simple-db-hw-2021.git (fetch)

upstream https://github.com/MIT-DB-Class/simple-db-hw-2021.git(push)

origin https://github.com/[your-repo] (fetch)

origin https://github.com/[your-repo] (push)

```

5. Let's test it out by doing a push of your master branch to GitHub by issuing the following:

```bash

$ git push -u origin master

```

You should see something like the following:

```

```

6. That last command was a bit special and only needs to be run the first time to setup the remote tracking branches.

Now we should be able to just run `git push` without the arguments. Try it and you should get the following:

```bash

$ git push

Everything up-to-date

```

If you don't know Git that well, this probably seemed very arcane. Just keep using Git and you'll understand more and

more. You aren't required to use commands like commit and push as you develop your labs, but will find them useful for

debugging. We'll provide explicit instructions on how to use these commands to actually upload your final lab solution.

(You don't need to follow these instructions until Lab 1.)

Pulling in labs that are released or previous lab solutions should be easy as long as you set up your repository based

on the instructions in the last section.

1. All new lab and previous lab solutions will be posted to the [labs](https://github.com/MIT-DB-Class/simple-db-hw)

repository in the class organization.

Check it periodically as well as Piazza's announcements for updates on when the new labs are released.

2. Once a lab is released, pull in the changes from your simpledb directory:

```bash

$ git pull upstream master

```

**OR** if you wish to be more explicit, you can `fetch` first and then `merge`:

```bash

$ git fetch upstream

$ git merge upstream/master

```

Now commit to your master branch:

```bash

$ git push origin master

```

3. If you've followed the instructions in each lab, you should have no merge conflicts and everything should be peachy.

Git is a distributed version control system. This means everything operates offline until you run `git pull`

or `git push`. This is a great feature.

The bad thing is that you may forget to `git push` your changes. This is why we **strongly** suggest that you check

GitHub to be sure that what you want us to see matches up with what you expect.

If at any point you need help with setting all this up, feel free to reach out to one of the TAs or the instructor.

Their contact information can be found on the [course homepage](http://db.csail.mit.edu/6.830/).

[join]: https://github.com/join

[resources]: https://help.github.com/articles/what-are-other-good-resources-for-learning-git-and-github

[ssh-key]: https://help.github.com/articles/generating-ssh-keys