Database Systems Prof. Dr. Jens Dittrich, Marcel Maltry, Immanuel Haffner

Dear students,

we imported the exam registrations from HISPOS and ViPa into the CMS and your personal status page should now show whether you registered. Please note that a subsequent registration is not possible.

We also assigned you to lecture halls for the exam. You can find the lecture hall you were assigned to on your personal status page. Pleas ignore row and seat.

Kind regards,

Marcel

Dear students,

in the following, we provide you with the most important information on the upcoming exam.

Time
Friday, February 17 at 10:00. Please be there at least 15 minutes ahead of time. The exam will take 2 hours. You are not allowed to leave the lecture hall early during the last 30 minutes of the exam.

Location
E2 2 GHH and E1 3 HSII. You will be assigned to either lecture hall via CMS before the exam after the registration period has ended. We will send a news once the assignment is done.

Permitted Materials
You are allowed to (and should) bring one A4 sheet of hand-written notes (front and back) and a non-programmable calculator. Please use a document-safe pen such as a ballpoint pen. No additional materials are permitted. We will provide you with enough paper so don't bring your own!

What to expect?
The exam consists of four exercises similar to the ones on the assignments. Each exercises should take you roughly 30 minutes.

Registration
Please refer to yesterday's news with regards to exam registration. You should now see on your personal status page whether you are admitted to the exam. Whether you are registered, will only be visible in CMS after the registration deadline once we imported the registrations from HISPOS and ViPa.

 

Trial Exam

The trial exam will take place during the regular lecture slot next week. We are trying to simulate a similar setting to the exam but with three exercises (90 minutes) instead of 4. The trial exam will be comprised of exam exercises from previous years. You are free to use any material but we suggest you already bring your cheat sheet and a non-programmable calculator. We will present the solutions to the trial exam during the lab slot on Friday. Both the exercises and solutions will be uploaded to the CMS after the lab.

If you have further questions, please send me an email or write in the forums.

Best regards and good luck,

Marcel

 

Dear students,

now that the deadline for Milestone 3 has passed, please register for the exam in HIS/POS (or ViPa) by Thrusday, 9 February 2023.

If you cannot register in HIS/POS due to your subject of studies (e.g. Erasmus), please reach out to me and I will register you manually. In all other cases, please contact the study coordination directly.

Note that you are only permitted to participate in the exam if you (1) scored at least 10 points in the first three milestones and (2) registered for the exam in time. There won't be any exceptions!

Kind regards,

Marcel

Update: You should now see on your personal status page whether you are admitted to the exam.

Dear all,

I just added the benchmarks for Milestone 3. You will have to compute optimal plans for five queries. These queries have a particular shape and size and are named accordingly, e.g. chain-12 is a query of 12 relations, joined together in a chain, i.e. T₀ ⋈ T₁ ⋈ ... ⋈ T₁₁.

You can use the Milestone 3 executable build/<TYPE>/bin/milestone3 to visually inspect the query graph and the plan you have computed.  For example, to inspect the chain-12 query, run

$ build/debug/bin/milestone3 resource/schema.sql resource/chain-12.{query.sql,cardinalities.json}

I suggest that you focus on functional correctness for Milestone 3 before tackling performance (and potentially more complex plan enumeration algorithms).

Good luck,

Immanuel

Dear students,

we have just released Milestone 3. The skeleton has been updated accordingly.

Please be aware that there are no benchmarks for Milestone 3, yet.  I will add them next week.  I might also extend the unit tests.  However, the skeleton, the assignment sheet, and the available unit tests should be enough to get started working on the milestone.

Good luck & regards,

Immanuel

Dear students,

we just added links to the Qualis course evaluation for the lecture and tutorials in the CMS under Information. Constructive criticism plays a crucial role in improving the course. So please take the time! The links are valid until February 2, 2023.

Thank you in advance and best regards,

Marcel

Dear students,

I just wanted to quickly remind you that all events both next week and the first week of January will be held online. In particular:

Next week (December 19 to 23):

• Monday: Tutorials will be held via Discord. More on that below.
• Wednesday: There will be a special Christmas lecture via YouTube with a text channel on Discord for you to ask questions. We won't give out an assignment sheet for this lectures, thus, there is no lab on Friday and no tutorial in the first week of January.

First week of January (January 2 to 6):

• Wednesday: There will be a regular lecture via YouTube with a text channel on Discord for you to ask questions. Since it is a regular lecture, there will be an assignment.
• Friday: Regular lab via Discord. More on that below.

If you have not yet registered on our Discord, please do so. You find all information here. Channels to be used for the tutorials, the lab, and the lecture are named appropriately within the Database Systems category.

Best regards,

Marcel

 

Dear all,

we were approached by one of your colleagues, who pointed out that there won't be a lab after holidays and before the deadline of Milestone 2.  To provide a lab where you can ask questions related to Milestone 2, we decided to postpone the deadline of Milestone 2 to January 10th. You can join our virtual lab via Discord on Friday, January 6th, to ask questions to Milestone 2. The Timetable and the programming assignmen sheet were updated accordingly.

Milestone 3 will hence be released on January 10th.  The extent of Milestone 3 will be adjusted to three weeks (from four weeks before).

We wish you all a Merry Christmas!

See you next year ;)

Immanuel

Dear students,

the evaluation of Milestone 1 is finished. You can see your score on the Database Systems Project Evaluation 🔗 website. I will assign the points for Milestone 1 in CMS during the next week.

Further, we have released Milestone 2. The description is available in the CMS → Information → Materials.  The skeleton repository has been updated accordingly.

Good luck with Milestone 2.

Immanuel

Dear all,

of course it had to happen: GitLab and the forum went offline just on the day of the deadline for Milestone 1. Both services are unreachable since Dec 6, around 22pm.

We are very sorry for this inconvenience. We are aware that this interferes with your submission of Milestone 1. Therefore, we will postpone the deadline of Milestone 1 by one more day. (This is tentative: should GitLab be unavailable for a longer period, then we will further postpone the deadline.) Don't panic if you were unable to push your latest changes yesterday. You will be able to do so when GitLab is back online and before we do the final evaluation of Milestone 1.

As a consequence of GitLab being unavailable, the benchmarks did not run tonight. I will rerun evaluation when GitLab is back online. You will receive mail from the evaluation, as usual.

Please do not send us mail regarding this issue, we are aware of it and working on it.

Kind regards,

Immanuel

Dear students,

some of you still use a mail address different from your student mail address in the CMS.  To make this very clear: you must set your student mail address in CMS and you must be assigned to your group's GitLab repository. Otherwise, you will not receive any points for the milestones!

Update your mail addresses, join your team in CMS, and then send me a mail with [dbsys22] in the topic.

Regards,

Immanuel

$ git fetch skeleton
$ git merge skeleton/main
$ git push

Dear students,

we updated the skeleton project to fix issues related to linking errors and building on macOS.  To update your project, please follow these steps:

$ git fetch skeleton
$ git merge skeleton/main
$ git push

If you encounter merge conflicts during the merge, this means that you modified a CMakeLists.txt file. Abort the merge with git merge --abort, undo your changes to the CMakeLists.txt file(s), and rerun the merge.

Note, that only one member of your group needs to perform this action.  After doing so, the other team members can simply do git pull to update their local repository.  Should you encounter any issues, please seek help in the forums.

 

Regards,

Immanuel

Dear students,

due to some technical issues related to Gitlab and the project in general, we decided to extend the deadline for milestone 1 by one week.

The new deadline for milestone 1 is December 6, 2022 at 23:59 UTC+1.

Note that this does not shorten the time for the remaining milestones.

Best regards,

Marcel

Dear all,

the recording of yesterday's lecture is available here: https://youtu.be/VlgrNmRg-uo
In contrast to what I announced initially, I will record the lectures (not the labs) and make them available soon after each lecture. However, I cannot guarantee that these recordings will work 100% of the time (it is very easy to run into audio issues with these recordings).

Best regards,

Jens Dittrich

Dear all,

we just finalized the tutorial assignment. You find the tutorial you were assigned to on your personal status page.

Tutorials are starting tomorrow. We will discuss the solution to Assignment 00 which will also be uploaded to the CMS later that day.

Best regards,

Marcel

Dear all,

if you are looking for a team to do the programming assignments with, we suggest you take a look at the forum. If you decide to open a thread, please use the appropriate categories. Once you found a team, indicate this in the thread so we can close it.

You must also register your team on your personal status page in CMS. For those not familiar with CMS, we will explain the process in the upcoming lab.

Best regards,

Marcel