Database Systems

Dear students,

as many of you have noticed, the CMS had problems during the technical test we just conducted.
As we are not hosting the CMS ourselves, we had to rely on the adimistrators to fix that problem.
They are already investigating the problem and the CMS should be up and running again in the near future.

To allow everyone to also test the submission process in the CMS, we have extended the submission until 8 pm in the evening, so everyone should have enough time to test it.
The download server will also remain online for at least that long, so if you couldn't download your exam so far, you can make up for it in the evening.
If you still encounter problems, contact us so we can resolve them before the exam.

As we might encounter similar problems during the actual exam, we will discuss internally how to handle submission in case the CMS goes down again.
We will announce this plan B and a recap of the most important information for the exam later.

Best regards
Christian

Dear students,

we have finally determined the exact regulations for the upcoming exam:

• The exam itself will be planned for 120 minutes (as initially also planned for the exam in presence). You will get an extra 30 minutes to download the exam in the beginning and to digitize your solution in the end, i.e. a total of 2 hours and 30 minutes
• As soon as the exam starts, you will be able to download your personalized exam on this webpage by entering your matriculation number and solving a captcha: https://playground.bigdata.uni-saarland.de/ (this website will also be linked in the CMS under "Information")
• As all your requests will arrive at our webserver within a short time, it might take a few seconds for the webserver to distribute all exams, so please be patient if you do not immediately receive your PDF
• The final submission will happen in the CMS. We will generate a submission where you can upload your solution as PDF file. You will find the submission linked on your personal status page. The maximum file size might be restricted by the server, we are currently discussing that with the administrators and will publish a possible limit later this week. UPDATE: The maximum file size allowed in the CMS will be 256 MB, which should be more than enough. But keep in mind that the time required for the upload highly depends on the upload speed of your local internet connection and the file size.
• The solution must be handed in before the deadline, so make sure you plan enough time to digitize your solution and to upload it to the CMS. We will not accept late submissions! In case of e.g. technical problems with the CMS, immediately contact us and make screenshots of possible error messages to prove that you actually tried to upload your solution in time.
• It is up to you to decide how you solve the exercises: E.g. printing them out, writing the solutions by hand and scanning them afterwards vs directly writing on a tablet using an appropriate pencil. Just make sure your solutions are legible in the end and you clearly state where to find the solutions for each exercise!
• We will be available on Discord to answer questions during the exam. In case you need a clarification on one of the exercises, you can join the "Exam Lobby" voice channel. One of the tutors will then take you to a private channel where you can ask your question. If you don’t have a working microphone, you can instead send a private text message to Christian Schön (don't post questions in one of the public channels). If one of the students finds a bug in one of the exercises, we will post a clarification in the “exam” text channel on Discord. So keep an eye on messages in this channel during the exam to be up to date.
• Maybe prepare a fallback plan in case your internet connection breaks. One possibility is a mobile hotspot through your smartphone which is usually easy to setup on Android and iOS devices.
• We will not have any form of surveillance e.g. via webcam (as we would have in a regular exam at university). We will therefore check the exams for plagiarism (which will result in a failed exam), so don’t even try to trick us!

To check that everything works as expected, we have organized a small technical test which will be held on Thursday, February 18th on 1 pm CET. You will have half an hour (exactly the extra time in the actual exam) to download your personalized test exam, to write down your name on the front page, to answer a very simple and short exercise (not related to or representative for the actual exam) and to finally upload your solution to a test submission in the CMS.
We highly recommend to take part in this test and to check that you are well prepared.
We also highly recommend to really go through the whole process of downloading, working on the exam and uploading the solution to get a feeling how long e.g. scanning the exam, converting it to a PDF and uploading it to the CMS really takes. Keep in mind that the actual exam will be longer, you will therefore also need more time to scan the actual exam than you will need for the test exam. You might also need some extra time to minimize the file size of your PDF for the actual exam (e.g. by lowering the resolution of your scanner or camera). So better take some time to experiment with these scenarios before the exam.

If you have questions regarding these regulations or experience problems during the test, please contact us as soon as possible such that we can solve all these problems before the actual exam starts.

Best regards
Christian

Dear students,

we are still monitoring the current pandemic situation.
Despite the current lockdown, the 7 days incidence has not decreased as much as we all hoped.
The incidence for Saarland is still twice as high as the targeted value of 50 infections per 100,000 inhabitants.

We were therefore discussing alternatives to exams held in presence and decided that we will move to an open book exam.
This means that we will still use our regular time slot on February 24th, but we will not meet in person in Saarbrücken.

The exams will be handed out online and you will submit them online as well after the expected duration of 2 hours (we will most likely grant you a little more time to digitize your solutions).
The overall topics as well as exercise types will not change due to this movement to open book exams.
In addition, we will not require you to have a camera turned on during the whole exam (no live surveillance).
But you will still need a stable internet connection (and maybe a fallback plan, e.g. a mobile hotspot) to download and submit the exam and to ask questions in case of unclear exercises.
Keep in mind that you still need to register for the exam in the CMS (deadline is on Sunday)!

Make sure you have some white paper available at the time of the exam such that you can directly start writing as soon as you have downloaded the exam.
To submit your solutions, we might require you to hand them in as PDF files, so make sure you have a scanner or camera available to digitize your handwritten solutions and combine them to a single PDF file.
You could also write your exam directly on your notebook/PC if you prefer that, but be aware that you might have to write down formulas and mathematical expressions which usually take more time to write on a notebook than by hand.

Be aware that plagiarism is still strictly forbidden and will result in a failed exam if we encounter fraud of any type!

We know that this decision might be a surprise for many of you.
Moving to an open book, online exam will reduce the risks of Corona infections for all of us, so we hope that you agree with our decision.
More information about the exact regulations (how to access the exam, where to submit it...) will follow as soon as we finalized them.

Best regards
Christian

Dear students,

the exam phase is now approaching and we want to give you an update on the regulations:

The final exam will be on February 24th, the re-exam one month later on March 24th.
Both exams will take place in the Günther Hotz lecture hall as well as two math lecture halls, start at 2:30 pm and last two hours.

We will distribute you to a fixed lecture hall after finishing the registration in the CMS (which allows us to keep track of possible contacts).
So make sure to register there until February 14th if you want to take the final exam. otherwise you will not be assigned a seat (the registration for the re-exam will follow later in March).
After assigning you to a lecture hall, we will also send you some additional information regarding the entrances you should use for each lecture hall and other information related to the current pandemic situation.
As entering and leaving the lecture halls in the current pandemic situation might take longer than usual, we ask you to be in front of your lecture hall at least 15 minutes in advance.
Please keep a safety distance of 1.5 m whenever possible, especially when waiting in front of the lecture halls or when leaving them after the exam.

The university has sent a mail to all students in the beginning of the week stating that they will provide masks for all exams held in presence.
As you must however also wear a mask when waiting in front of the lecture hall or when using the public transport to get to the campus, you will still need to bring your own mask to the exam, no matter what the university might prepare in the lecture halls.
Keep in mind that only medical masks or FFP2/KN95/N95 masks are allowed, but no face shields or self-made / community masks.

You are allowed to bring two double-sided A4 sheets with handwritten notes to the exam, i.e. four pages in total.
In addition, you are allowed to bring a calculator (which is not programmable).
Cell phones, smart watches and other electronic devices (besides the calculator) are not allowed.

The exam might cover all topics of the lecture except for the MVCC part (i.e. the second part of the MVCC lecture). The first part of this lecture up to the break (e.g. covering Virtual Memory) is however relevant!
The exercises of the exam will be similar to the exercises on the assignment sheets, so going through them once again is a good exam preparation.
There might be a Q&A exercise in form of multiple choice questions or in form of small statements for which you should briefly explain whether they are correct or not.

As we reached the final week of the lecture period, we will have no more tutorials or labs.
If you have questions regarding the lecture contents or the assignment sheets, you can ask them in the forum.

We wish you good luck for your exam preparation.
Best regards
Christian

Dear students,

we have finished the performance evaluation of the project and determined a grading scheme which Immanuel explained in the forum.
You will already find the points your team has scored in this final part of the project in the forum post.

It will however take some time to enter all the results in the CMS manually, so please be patient if you do not yet see your points there.

Please remember to register for the exam in the CMS, in addition to registrations you have done previously in other systems.

Best regards
Christian

Dear students,

the university has updated the regulations for the upcoming exam phase.
According to these rules, all students have to wear a mask at all times, not only when moving inside the lecture hall, but also when waiting outside before entering the hall or during the exam itself.
Due to their limited protection, face shields and community masks are no longer permitted.
You have to wear a medical mouth-nose protection (surgical mask) or a FFP2 / KN95 / N95 mask (similar to the governmental rules currently in effect).
The university will not provide you these masks, so make sure to buy some masks yourself and to bring them to the exams.

To organize the exams, we have just opened a registration here in CMS (it should be visible on your personal page).
We ask all students that want to take the exam to register there, in addition to registrations in LSF / Vipa / other systems depending on your course of study.
This will allow us to plan the exam and assign you to different lecture halls later on.
The registration is coupled with the project results, i.e. you can only register if you also passed the project by achieving at least 10 out of 20 points.
As some of you might need a few additional points from the performance evaluation, we will try our best to enter the results in the CMS as soon as possible.
The registration deadline is February 14th, so make sure to register in time.

We will send you additional information regarding the exams such as the lecture hall you are assigned to, the entrance you should use and other safety rules that apply in the days before the exam.

Best regards

Dear students,

as you might have already noticed in the calendar, this week is the last week of our course (except for the exams).
The lecture is therefore planned as a quick recap of the course.
We will not introduce new content and not provide a new assignment sheet on Wednesday.

This will also affect the lab on Friday which is transformed into an office hour.
You can use this time to recap and discuss the lecture contents or the assignment sheets in small groups.
As usual, our teaching staff will be available to answer questions.
We will use the standard time slot starting at 12:15 pm, feel free to join us on Discord.

Best regards
Christian

Dear students,

the 10th and last assignment sheet is now available under Materials.
As the lecture next week is planned as a recap session which will not introduce new content, we will not have an additional assignment sheet next week.
We will still have our usual lab on Friday as well as next weeks tutorials to cover the contents of the current assignment sheet.

Keep in mind that the exam registration in LSF ends today.
The Qualis course evaluation is still open until Friday, so please use this opportunity to provide us helpful feedback.

Best regards
Christian

Dear students,

The plan the faculty agreed on in the beginning of the winter term was to hold all lectures online, but the exams in person on our campus in Saarbrücken.
However, the student council has informed us that some students coming from abroad might be unable to attend the exams in person, e.g. due to travel restrictions or missing visa caused by the current pandemic situation.

If some of you aren't able to attend the exams in person due to such restrictions, we ask you to get in touch with us until Thursday by sending me a mail stating: a) where you come from and b) why you cannot attend the exams in person (mail address: christian.schoen(at)uni-saarland.de)
In addition, we ask you to monitor the regulations in your home country as well as possible travel restrictions for Germany and to inform us if your situation changes in the upcoming weeks until the exams in February or March.
This helps us planning the exams and finding suitable solutions for those of you coming from abroad.

As far as we know, there are currently no restrictions considering travels inside Germany.
Even the 15km restriction for Corona hotspots has an exception for travels related to work and school (which should cover the case of an exam at our university).
This problem should therefore only affect students coming from abroad (at least according to the current regulations we are aware of).

Best regards
Christian

Dear students,

Assignment 9 is now available under Materials.

As we already received some questions regarding the exam, here a few clarifications:

The exam will take place on February 24th, the reexam exactly one month later on March 24th.
Keep in mind that you need to register for the exam in LSF (or the corresponding system for your course of study if you're not in the computer science program).
The registration deadline in LSF for the exam in February ends next week on January 27th, so make sure you are registered if you want to take the exam.
We are currently planning to allow you to bring two double-sided sheets of paper to the exam, all of them handwritten (i.e. 4 pages of notes in total).
The exercises you will encounter in the exam are comparable to those on the assignment sheets.
The exercises might also include some Q&A style questions as done in the Labs on Friday.
As stated on the main CMS page, you will need 50% of the total points in the project to be admitted.
Even when scoring more than 50% of the points in the project, you will still need to pass the exam independently of the project.
This means in particular that scoring all points in the project does not free you from taking the exam.
All other information regarding the lecture halls for the exam etc. will be given later.

If you haven't done so, please participate in the Qualis course evaluation as it helps us to improve the course in the future:

Evaluation form for the lecture:
https://qualis.uni-saarland.de/eva/?l=126728&p=tvj67i
Evaluation form for the tutorials:
https://qualis.uni-saarland.de/eva/?l=1267281&p=ubvvxv

Best regards
Christian

Dear students,

we just published the next assignment sheet. You can find it under Materials, as usual.

In addition, you are now given the opportunity to provide us feedback on the course using the university's Qualis evaluation. Due to the current Corona situation, the evaluation will be conducted online. You are asked to fill out two forms: One for the lecture in general and an additional one for the tutorials. We highly encourage you to use this opportunity to provide feedback as it helps us to improve the course in the future. The evaluation forms will be available until January 29th under the following links:

Evaluation form for the lecture:
https://qualis.uni-saarland.de/eva/?l=126728&p=tvj67i
Evaluation form for the tutorials:
https://qualis.uni-saarland.de/eva/?l=1267281&p=ubvvxv

Best regards
Christian

Dear students,
we have just released the 7th assignment sheet as well as Milestone 3 for the project.
The assignment sheet will be topic of the Lab on Friday as well as the tutorials next week.

Milestone 3 will be due on January 27th, 23:59 UTC+1, i.e. in 3 weeks from now. We wish you good luck!
We have also entered the points you achieved in the project so far in the CMS (including Milestone 2), so you should see them on your personal status page.

As mentioned on the main CMS page, you will need 50% of the total points to be admitted to the exam, i.e. 10 out of the 20 points you can score in the project.

Best regards
Christian

Dear students,

we just released Milestone 2. As usual, you find the PDF document in the CMS Materials section. The 2nd milestone is due January 5, 2021, 23:59 UTC+1.

To be able to work on Milestone 2, you must update your project with the new contents of the skeleton. To do so, run

$ git fetch skeleton
$ git merge skeleton/master

All the best,

Immanuel

Dear students,

Assignment 5 is now available in the CMS, covering different join and sorting algorithms.
The solutions will be discussed (as usual) in next week's tutorials.

If you haven't noticed: The exam registration is now open in HISPOS/LSF.
You will find two dates there: the final exam on February 24th and the reexam on March 24th.
You should be able to register for one of the two dates, but not for both at the same time.
This is due to the restriction that you will need to receive your grades of the first exam before you can register for the second exam.
We therefore recommend to first register for the final exam if you want to take it.
After receiving your grade for this exam, there is still some time left to register for the reexam.

The registration (and unregistration) for the final exam is open until January 27th.
The registration (and unregistration) for the reexam is open until March 17th.

Some students (e.g. Business Informatics, Erasmus) might not be eligible to register through the HISPOS/LSF.
Please get in touch with your examination office if you need more information on how to register for exams in your study program or if you experience problems during registration.

Please keep in mind that Milestone 1 of the project is due on Sunday evening, so about 4 days left to work on it.

Best regards
Christian

Dear students,

as we had some bugs in mutable that affected your work on the project, we decided to grant you an extension of the deadline for Milestone 1. The first part of the project is now due Sunday, December 13th 23:59 UTC+1. The release of the second Milestone is also moved to the following Monday. This gives you an additional 5 days to work on the first project part. Our calendar has been updated accordingly.

We really encourage you to make active use of our forum: either to raise questions or to discuss problems with your fellow students. Discussions in the Lab might be fine if you have very specific questions related to your team's implementation, but most of the more general questions might be of interest for all of your fellow students. Asking them in the forum allows everyone to profit from the discussions in the respective thread. And it saves time as the same question does not need to be answered multiple times. So if you have questions, the chance is there that you will already find your answer in the forum.

We wish you good luck for the first project part and hope you can benefit from the additional time!

Christian

Dear Students,

Assignment 4 is now available under Materials.

As some of you might have already noticed, we have also prepared a project evaluation website for you which is linked in the menu under Information. This page provides for each team information about the percentage of tests passed per Milestone as well as the total number of tests passed over time. This might help you identify points in time were your project implementation made progress (or maybe also a step back).

Please keep in mind that the first Milestone is due next Tuesday 23:59 UTC+1, so less than one week remaining. Make sure that you upload your final implementation to the master branch ahead of time (we will not consider implementations available on other branches in your repository).

Best regards

Christian

Dear students,

some teams seem to misunderstand the description for the team registration phase. The Milestones 0 & 1 clearly mention that we cannot assign you to your team's repository if you haven't logged in to GitLab at least once before, as your accounts are invisible up to that point. This requirement does not only affect the team member sending the mail, but also all other team members.

As we expect all participants of this course to actively work on the project, we also expect every student to have a GitLab account which we can properly link to the team's repository. Therefore please check that each team member has logged in at least once before sending your team registration by mail. All teams that have already sent a mail, should check for all team members that everyone has been assigned correctly to the team's repository. In case you can not see your repository after logging in to GitLab, get in contact with Immanuel by sending an email including "[dbsys20]" in the subject. Please mention your team name as well as your full name, matriculation number and student email address in the mail content as described in Milestone 1.

We might not grade the project for students which do not have a GitLab account properly linked to the team's repository. As the project is not deemed to be done by a single student for the whole team, we consider this as a minimum requirement for project participation which every student must fulfill. If you have any problems signing in to GitLab, let us know through the forum or by mail, we will try to solve these problems.

Hope to see you in the Lab at 12:15 pm on Discord or in the tutorials next week on Zoom (links will follow in the calendar).

Best regards

Christian

Dear Students,

we have just released the Assignment 2 as well as Milestone 1 for the project.

Unfortunately, not all students registered in the CMS have also registered with a team for the project. Keep in mind that you can not pass the course without the project. Therefore please check if you can  1) log in to Gitlab sucessfully and 2) see your team's repository. If either of these two steps failed, you have not yet correctly registered for the project. In that case, please follow exactly the registration steps given in Milestone 1. We will then try to (re-)assign you to your repository after receiving your mail.

Besides the registration steps, Milestone 1 also contains all necessary information to get you going for the first part of the project in which you will implement a row as well as a column store. Please read the instructions carefully! The deadline for this first milestone is on December 8th, 23:59 UTC+1.

The Vagrant file is now also available in the Materials section of the CMS if you need an easy to set up virtual machine for the project. An instruction on how to use Vagrant is also linked under Information.

The Assignment 2 covers the content of this week's lecture. We highly recommend to work on these assignments as an exam preparation (e.g. in the upcoming Lab on Friday). The solutions will be presented in next week's tutorials.

As always, feel free to use the forum whenever you have questions regarding assignment sheets or project milestones. Our Discord server is available 24/7 if you need a platform to discuss assignments or milestones within your team. Just create a team voice channel and join it with all your team members. Consider locking the voice channel after all members joined it to avoid non-team-members to also join your channel. Keep in mind that sharing solutions across teams is not allowed and will be considered a fraud.

We wish you good luck for the first project part and hope to see many of you in the next Lab on Friday.

Best regards

Christian

Dear students,

the tutorials have been moved to the video conference tool Zoom. Although invitations can be accepted by just clicking on a link, you will need the Zoom client to be able to join a meeting. Please follow the official documentation to install and setup Zoom. After installing the client, you can test Zoom and familiarize yourself with the tool in advance by joining a test meeting on their website.

To join the tutorial itself, it will then later be sufficient to just click on the corresponding links which are given in our calendar. As the link might change per tutorial, we ask you to check the CMS for updated links before each tutorial. The link for today's tutorial with Immanuel (2:15 pm) is already published, the link for tomorrow will follow later.

Best regards

Christian

Dear Students,

as most of you noticed today, screen sharing in Discord is limited to 50 persons. Unfortunately, we are currently unable to increase that limit. As our tutorials on Monday and Tuesday might also be affected by this limit (depending on the number of participants), we are currently discussing to switch to the video conference tool Zoom. As we have to reorganize the tutorials, I can not provide you the exact credentials for Monday and Tuesday at the moment. Please check our CMS (especially the corresponding events in our calendar) again on Monday before the tutorials start. We will provide you the necessary information by then.

We have also discussed the content for the upcoming tutorials and came to the conclusion that it might be better to already discuss the solutions for assignment 1 next week, i.e. on November 16th and 17th. This allows us to focus  exclusively on the topics of the first week before new content will be introduced in Wednesday's lecture.

Regarding the choice of time slot: We do not plan to assign you to a fixed tutorial at the moment, so you are free to choose the time slot that fits you best.

Best regards

Christian

Dear students,

we have just released the first assignment sheet and Milestone 0 of the project, you can find both in the menu under Information -- Materials.

As we have already announced in the beginning of the course, you will not need to hand in any of the weekly assignment sheets as we will not grade them. However, these assignment sheets contain exercises that are similar to those that you will encounter in the exam. We therefore highly recommend to spend some time on solving the exercises. The LABs will be held on Discord starting this Friday 12:15 pm, you will find a corresponding text as well as voice channel there. In each week's LAB, we will start with a short, interactive recap of the lecture before you can team up in small groups to work on the assignment sheet of the week (ideally the groups you already formed for the project, but not necessarily). Our team of tutors will be present in the LAB such that you can ask questions regarding the exercises. The solutions will be presented in the tutorials on Monday and Tuesday. As we want to give you at least a full week to work on the exercises, the solutions for assignment 1 will be discussed on November 23rd and 24th.

Milestone 0 of the project asks you to form teams of three students and to register for the project. The PDF contains all details necessary to prepare for the first (real) project milestone which is scheduled to be published next week's Wednesday. In each of the upcoming milestones, we will ask you to implement a specific component of a database system in a time period of roughly 3 weeks (excluding holidays). As we need to prepare a few things in the background (e.g. your git repositories), we ask you to register your team no later than November 17th. Details on the steps necessary to register are given in the PDF. All further information regarding the database components to implement, the steps required to do so etc. will be described in the corresponding project milestones which are released at a later point in time. The handouts (i.e. publication dates) and deadlines are included in our calendar, if you already want to schedule team meetings.

If you still need team members for the project or have questions regarding the lectures, assignment sheets or project milestones, feel free to use our forum.

Best regards

Christian

Dear students,

we will start our course Database Systems with our first lecture tomorrow at 12:15 pm on YouTube. All lectures will be streamed live on Prof. Dittrich's channel. We will publish direct links to each week's lecture in our calendar which you can find in the menu under Information.

If you have questions during the lecture, you can ask them anonymously using an online tool called frag.jetzt for which a link is also provided in the Information section of the menu. The tool's user interface is provided in German and English, you can toggle the language at the bottom of the page. However, we ask to you formulate your questions in English such that all students understand them. Your questions will be moderated, it might therefore take a second for a question to become visible for all.

Besides frag.jetzt, you usually have the opportunity to ask questions in short office hours by Prof. Dittrich during the lecture break or shortly after the lecture. These office hours will be held on Discord. Please follow the Discord Guide linked in the menu under Information to join our server.

In addition, we offer you a forum to ask questions that arise after the lecture or to discuss topics with your fellow students and our team.

All further information regarding the course and its topics will be given in tomorrow's lecture.

Best regards

Christian