Database Systems Prof. Dr. Jens Dittrich, Ankur Sharma, Immanuel Leonard Haffner Core Lecture, 9 CP, Winter Semester 2018

News

02.04.2019

Re-exam grades are now available on CMS

Hello students,

The grades for the re-exam are now avaible on the CMS. If you did not appear in the re-exam and you did not register for it, it might still show as a fail in CMS. You can ignore the pass status of re-exam in that case. The grade shown in CMS is... Read more

Hello students,

The grades for the re-exam are now avaible on the CMS. If you did not appear in the re-exam and you did not register for it, it might still show as a fail in CMS. You can ignore the pass status of re-exam in that case. The grade shown in CMS is the best of the two exams.

We have decided to normalize the re-exam points to 76/100. So the passing point for the re-exam is 38/100. The gradescale is same as the end-of-term exam.

We will organize the exam inspection on Friday between 12:00 and 14:00.

Best regards,
Ankur Sharma
20.03.2019

Re-exam on 21.03.2019

Hello students,

Please note that the re-exam will be held tomorrow i.e on Thursday, 21.03.2019 at Geb. E2 2, Günter-Hotz-Hörsaal. We will start sharp at 10:00 AM. The duration of the exam will be 120 minutes. You are allowed to bring two double-sided A4 sheets... Read more

Hello students,

Please note that the re-exam will be held tomorrow i.e on Thursday, 21.03.2019 at Geb. E2 2, Günter-Hotz-Hörsaal. We will start sharp at 10:00 AM. The duration of the exam will be 120 minutes. You are allowed to bring two double-sided A4 sheets of handwritten notes as well as a calculator to the final exam. Anything else including jackets, cell phones and smartwatches are not allowed. We expect you to arrive at Geb. E2 2, Günter-Hotz-Hörsaal at least 10 minutes before the start of the final exam.
 
Best,
Ankur Sharma
27.02.2019

Grades now available on the CMS

Hello students,

We have published the grades on the CMS.

We have normalized the midterm points, and the final exam points to 80. So if you have 40 points in the midterm, and the final exam, you will now see your points to be 50. 40/100 = 40% has been changed... Read more

Hello students,

We have published the grades on the CMS.

We have normalized the midterm points, and the final exam points to 80. So if you have 40 points in the midterm, and the final exam, you will now see your points to be 50. 40/100 = 40% has been changed to 40/80 = 50%. Passing points for the exam will still be 40/100. We have reduced the passing points for the programming assignments to 18/40.

Your total points (Database Systems) = ((Prog / 0.4) x 0.3) + (Midterm x 0.2) + (Exam x 0.5), where Prog is your points in the programming assignment, Midterm is your normalized points for the midterm, and Exam is the normalized points in the final exam.

Grading Scheme:

Grade Min (Inclusive) Max (Exclusive)
1,0 84,00 -
1,3 80,00 84,00
1,7 75,00 80,00
2,0 71,00 75,00
2,3 67,00 71,00
2,7 62,00 67,00
3,0 58,00 62,00
3,3 54,00 58,00
3,7 49,00 54,00
4,0 45,00 49,00
5,0 0 45,00

 

 

 

 

 

 

 

 

 

 

Best,
Ankur Sharma
25.02.2019

Exam inspection on Thursday between 14:00 and 16:00

Hello students,

We will organize the exam inspection for the final exam on Thursday, 28.02.2019 between 14:00 and 16:00 at R3.06, E11.

Best,
Ankur Sharma
21.02.2019

Points for the final exam are available on the CMS

Hello students,

The points for the final exam are available on the CMS. We have decided to reduce the passing points to 40 points out of 100. We will send a separate email with the details on the exam inspection.

Best,
Ankur Sharma
12.02.2019

Update on cheat sheets for the exam

Dear students,

we discussed the matter internally. Due to the short notice, we decided to lift the constraint regarding the solutions to exercise sheets for the exam cheat sheet.

That means you are allowed to write your summary including solutions to exercise... Read more

Dear students,

we discussed the matter internally. Due to the short notice, we decided to lift the constraint regarding the solutions to exercise sheets for the exam cheat sheet.

That means you are allowed to write your summary including solutions to exercise sheets on your two double-sided A4 sheets of handwritten notes.

We apologize for the inconveniences and wish all of you good luck in the exam.

Best,

Marcel

12.02.2019

Regarding the concerns about cheatsheet content.

Hello students,

As written in the Administrative Notes Section 2.e (visible since 18.10.2018):

"You can take two two-sided physical A4-pages of your personal handwritten summary of the lecture content to the midterm and all exams (no print-outs, no exam... Read more

Hello students,

As written in the Administrative Notes Section 2.e (visible since 18.10.2018):

"You can take two two-sided physical A4-pages of your personal handwritten summary of the lecture content to the midterm and all exams (no print-outs, no exam question sheets, no carbon copies)"

We do not think solutions to the exercise sheet counts as a summary of the lecture content. So, we unfortunately cannot allow solution to assignments in the cheatsheet.

Best,
Ankur
12.02.2019

Final exam on 13.02.2019

Hello students,

Please note that the final exam will be held on Wednesday, 13.02.2019 at Geb. E2 2, Günter-Hotz-Hörsaal. We will start sharp at 10:00 AM. The duration of the exam will be 120 minutes. You are allowed to bring two double-sided A4 sheets of... Read more

Hello students,

Please note that the final exam will be held on Wednesday, 13.02.2019 at Geb. E2 2, Günter-Hotz-Hörsaal. We will start sharp at 10:00 AM. The duration of the exam will be 120 minutes. You are allowed to bring two double-sided A4 sheets of handwritten notes as well as a calculator to the final exam. Anything else including jackets, cell phones and smartwatches are not allowed. We expect you to arrive at Geb. E2 2, Günter-Hotz-Hörsaal at least 10 minutes before the start of the final exam. You are not allowed to write solutions to exercise sheets in your cheatsheet.
Best,
Ankur Sharma
05.02.2019

Solutions to assignment sheet 12

Hello students,

You can find the solutions to assignment sheet 12 in the materials section of CMS (just under the Assignment Sheet 12).

Best,
Ankur
29.01.2019

Lecture (NoSQL) Today

Dear students,

just like the programming LABs, the lecture today about NoSQL will be in the Math Building (E2.5 HS0.01) at 14:15.

28.01.2019

Evaluation of Milestone 3

Dear students,

below you find the grades for Milestone 3. The grading scheme is similar to that of previous milestones.

team, milestone3
ADBMSC, 10.0
BobbyTables, 10.0
ERNSTL, 10.0
first, 10.0
indexers, 10.0
LoRaWAN,  7.5
MangoDB, 8.0
MarioKart,... Read more

Dear students,

below you find the grades for Milestone 3. The grading scheme is similar to that of previous milestones.

team, milestone3
ADBMSC, 10.0
BobbyTables, 10.0
ERNSTL, 10.0
first, 10.0
indexers, 10.0
LoRaWAN,  7.5
MangoDB, 8.0
MarioKart, 10.0
no_disk_no_fun, 8.0
WannaIXIUs, 10.0
15.01.2019

Exam Registration for students of Master Entrepreneurial Cybersecurity

Dear students,
 
Unfortunately a registration in HISPOS is still not possible for Master Entrepreneurial Cybersecurity students. Please inform the lecturers/assistants that you would like to take the exam and a registration in HISPOS is not possible. You... Read more
Dear students,
 
Unfortunately a registration in HISPOS is still not possible for Master Entrepreneurial Cybersecurity students. Please inform the lecturers/assistants that you would like to take the exam and a registration in HISPOS is not possible. You will receive a certificate, which you submit to the examination office.
 
Best regards,
Evelyn Kraska
07.01.2019

Talk by Uwe Röhm, U Sydney: Serialisable Snapshot Isolation on Multicore Servers, Jan 8, 14:15

Title:
Serialisable Snapshot Isolation on Multicore Servers

Abstract:
Database systems strive to provide efficient read/write access to large, shared data sets. At the core of these systems sits the concurrency control component whose role is to isolate... Read more
Title:
Serialisable Snapshot Isolation on Multicore Servers

Abstract:
Database systems strive to provide efficient read/write access to large, shared data sets. At the core of these systems sits the concurrency control component whose role is to isolate concurrent transaction executions. Modern database workloads are dominated by queries though, which makes snapshot databases based on a multi-version storage layer an attractive system design. It is well known that snapshot-based algorithms scale better for read-only transactions than locking-based systems. However, a major pitfall is that the standard snapshot isolation (SI) algorithm allows non-serialisable executions...

This talk revisits the development of snapshot based concurrency control algorithms and discusses an efficient approach to provide serialisable snapshot isolation inside a database system - with almost the same performance than standard SI. We further take a look at scalability of SI-based database engines on multicore servers. We will show that current implementations of SI do not scale well as number of CPU cores increases, and then discuss approaches to avoid this scalability bottleneck with modern database systems on modern multicore servers.

About the Speaker:
Uwe Roehm is Associate Professor in database systems at the University of Sydney. He is a computer science graduate from the University of Passau, Germany, and completed his PhD at ETH Zurich in the area of scheduling combined OLTP/OLAP workloads in a cluster of databases. Much of his research has dealt with transaction management and replication, especially how to ensure sufficient freshness in values read. His current research interests are cloud data management, database engines on modern hardware, and in-database support of complex data-intensive computations, eg. for Data Science. He has been a visiting researcher at Microsoft, and held visiting positions at the Karlsruhe Institute of Technology (KIT), and at TU Munich. He currently is guest professor at the data management group of TU Darmstadt, Germany.

When:
Tuesday, Jan 8, 14:15

Where:
E1 4, 024
03.01.2019

Evaluation Milestone 2

Dear students,

below you find a table of points you achieved in Milestone 2. The grading scheme is similar to that of Milestone 1.

team, milestone2
38, 10.0
ADBMSC, 10.0
BobbyTables, 10.0
BubbleTeam, 5.0
CHI, 10.0
ERNSTL, 10.0
first, 10.0
indexers, 8.5
... Read more

Dear students,

below you find a table of points you achieved in Milestone 2. The grading scheme is similar to that of Milestone 1.

team, milestone2
38, 10.0
ADBMSC, 10.0
BobbyTables, 10.0
BubbleTeam, 5.0
CHI, 10.0
ERNSTL, 10.0
first, 10.0
indexers, 8.5
LoRaWAN, 10.0
MangoDB, 10.0
MarioKart, 10.0
MIT, 10.0
no_disk_no_fun, 10.0
TiTiSe, 10.0
WannaIXIUs, 10.0

Teams that are not listed did not achieve any points (= 0 points).

 

Regards & happy new year,

Immanuel

24.12.2018

Milestone 3

Dear students,

we just released Milestone 3. The deadline is Jan 27th, 23:59 UTC+1.

Regarding Milestone 2, I will compile and publish the list of points in the first week of January. The grading scheme will be similar to that of Milestone 1.

Best regards... Read more

Dear students,

we just released Milestone 3. The deadline is Jan 27th, 23:59 UTC+1.

Regarding Milestone 2, I will compile and publish the list of points in the first week of January. The grading scheme will be similar to that of Milestone 1.

Best regards and merry christmas :)

Immanuel

06.12.2018

Tutorials for next two weeks

Hello students,

As already informed in the respective tutorials, please note that the Tuesday 12:00, and Wednesday 12:00 tutorials are cancelled for next two weeks. In replacement to this, we will organize an alternative tutorial on Wednesday 14:00. Also note... Read more

Hello students,

As already informed in the respective tutorials, please note that the Tuesday 12:00, and Wednesday 12:00 tutorials are cancelled for next two weeks. In replacement to this, we will organize an alternative tutorial on Wednesday 14:00. Also note that Monday 10:00 slot will run as scheduled.

We will also schedule an additional tutorials for students who are unable to attend any tutorials in January.

Best,
Ankur Sharma

 

 

 

03.12.2018

Midterm inspection

Hello students,

The midterm inspection will be organized on Wednesday, December 05 between 14:00 and 16:00 at R3.06 E1.1. If you are not available for any reason on the given date and time, please write me an email as soon as possible to schedule a different... Read more

Hello students,

The midterm inspection will be organized on Wednesday, December 05 between 14:00 and 16:00 at R3.06 E1.1. If you are not available for any reason on the given date and time, please write me an email as soon as possible to schedule a different slot.

Best,
Ankur Sharma
(ankur.sharma@bigdata.uni-saarland.de)
03.12.2018

Midterm grades are availble on the CMS

Hello students,

The grades for midterm are now available on the CMS. We plan to have a midterm inspection this Wednesday. We will send the exact schedule by today evening.

I will organize a single tutorial to discuss the midterm exercises tomorrow at 12:00 in... Read more

Hello students,

The grades for midterm are now available on the CMS. We plan to have a midterm inspection this Wednesday. We will send the exact schedule by today evening.

I will organize a single tutorial to discuss the midterm exercises tomorrow at 12:00 in R3.06, E1.1. I will try to resolve all your concerns regarding the midterm which might come handy for the final exam.

There is no passing points for the midterm.

Best,
Ankur Sharma
29.11.2018

Next Programming LAB

Dear students,

we will offer a Programming LAB to introduce Milestone 2. As usual, the LAB is in E2.5 HS0.01 at 14:15. You can also find it in the timetable.

Regards,

Immanuel

26.11.2018

Programming Project: Milestone 2

Dear students,

we have released Milestone 2 of the programming project. The deadline of Milestone 2 is Dec 23, 23:59.

Best of luck,

Immanuel

26.11.2018

Evaluation of Milestone 1

Dear students,

the deadline for Milestone 1 has come and we evaluated your current state of the project. Below you find a table with the points you achieved in milestone 1. You can achieve up to 10 points per milestone and an additional 10 points in the... Read more

Dear students,

the deadline for Milestone 1 has come and we evaluated your current state of the project. Below you find a table with the points you achieved in milestone 1. You can achieve up to 10 points per milestone and an additional 10 points in the performance evaluation; this makes a total of 40 points. For milestone 1, we split points 50/50 between unit tests and integration tests.

38, 10.0
ADBMSC, 10.0
BobbyTables, 10.0
ERNSTL, 10.0
first, 10.0
indexers, 7.5
LoRaWAN, 5.0
MangoDB, 10.0
MarioKart, 10.0
MIT, 10.0
no_disk_no_fun, 10.0
ref, 10.0
TiTiSe, 5.0
WannaIXIUs, 10.0

Teams that are not listed did not achieve any points (= 0 points). In the forums I will explain how you can check which commit we evaluated for grading.

 

Regards,

Immanuel

26.11.2018

MidTerm on Thursday 29.11.2018 at 10:00 AM

Hello students,

Please note that the midterm will be held on Thursday 29.11.2018 at A1.7 R5.1. We will start sharp at 10:15 AM. The duration will be 90 minutes. No registration is required for the midterm. You are allowed to bring two double-sided A4 sheets of... Read more

Hello students,

Please note that the midterm will be held on Thursday 29.11.2018 at A1.7 R5.1. We will start sharp at 10:15 AM. The duration will be 90 minutes. No registration is required for the midterm. You are allowed to bring two double-sided A4 sheets of handwritten notes as well as a calculator to the midterm. Anything else including jackets, cell phones and smartwatches are not allowed. We expect you to arrive at A1.7 R5.1 at least 10 minutes before the start of the midterm.
Best,
Ankur Sharma
16.11.2018

Exam registration

fyi

 
Anfang der weitergeleiteten Nachricht:
Von: Evelyn Kraska <kraska@cs.uni-saarland.de>
Betreff: [Doz-ws2018] Prüfungsanmeldung HISPOS Informatik/Exam registration in HISPOS for Computer Science
Datum: 13. November 2018 um 07:39:23 MEZ

fyi

 
Anfang der weitergeleiteten Nachricht:
Von: Evelyn Kraska <kraska@cs.uni-saarland.de>
Betreff: [Doz-ws2018] Prüfungsanmeldung HISPOS Informatik/Exam registration in HISPOS for Computer Science
Datum: 13. November 2018 um 07:39:23 MEZ
 

Liebe DozentINNen des Wintersemesters 2018/19,

alle Studierenden (siehe Anhang) sind aufgefordert, sich im HISPOS System zu den Prüfungen im Wintersemester 2018/19 anzumelden. Die Prüfungsan- bzw. -abmeldung ist bis eine Woche vor der Haupt- bzw. der Nachklausur möglich. Eine nachträgliche Prüfungsanmeldung seitens der Studienkoordination ist aufgrund der kurzen Zeitspanne bis zur Klausur nur noch mit Zustimmung des Dozenten möglich.

Für Seminare/Proseminare ist eine An- bzw. Abmeldung bis drei Wochen nach der Themenvergabe bzw. Kick-Off-meeting möglich.

Bitte weisen Sie in Ihren Lehrveranstaltungen gesondert auf die verpflichtende Prüfungsanmeldung hin.

Folgende Studierende können sich nicht in HISPOS anmelden:

Wirtschaftsinformatiker
Erasmusstudenten
Juniorstudenten
Gasthörer
zum Teil Studierende anderer Studiengänge


Sollte es  Probleme bei der Anmeldung geben, können sich die Studierenden (Informatik, Medieninformatik, CuK, Eingebettete Systeme Visual Computing, Cybersicherheit, Promotion vorb.) gerne an: studium@cs.uni-saarland.de wenden. Andere Studenten an das für sie zuständige Prüfungssekretariat.

Vielen Dank und viele Grüße
Evelyn Kraska


Dear Lecturers of the winter semester 2018/19,

all students are  asked to register for the exams for the winter semester 2018/19 (please see attachment). Exam registration or a withdrawal is possible until one week before the main exam or the re-exam. A subsequent exam registration by the study coordination is only possible with the agreement of the lecturer because of the short period before the exam.

Seminars:
Students are only allowed to withdraw a seminar within three weeks after topic assignment or the briefing of the seminar. 


Please remind your students of the exam registration.

These students are not able to register in HISPOS:
 

Wirtschaftsinformatiker (Business Informatics)
Erasmusstudents
guest students
to some extent students from other course of studies


In case of problems wih the exam registration the students (Informatik, Medieninformatik, CuK, Visual Computing, Cybersicherheit, Promotion vorb.)  should contact:
studium@cs.uni-saarland.de

Other students have to contact their examination office.
Thank you.

Best regards,
Evelyn Kraska

-- 
-------------------------------------------
Evelyn Kraska 
Sekretariat Studienkoordination Informatik
Universität des Saarlandes
Postfach 15 11 50
Saarland Informatics Campus, Geb. E 1.3, Raum 208
D-66041 Saarbrücken

Tel.: +49(0)681 302-6581
Fax: +49(0)681 302-58094
Email: kraska@cs.uni-saarland.de
Web: https://informatics-campus.saarland/
-------------------------------------------
_______________________________________________
Doz-ws2018 mailing list
Doz-ws2018@milaman.cs.uni-saarland.de
https://milaman.cs.uni-saarland.de/mailman/listinfo/doz-ws2018
13.11.2018

Office hours/Programming tutorial today

Hello students,

Please take a note that the programming tutorial/office hours are scheduled today at 14:15 in E1.1 R3.06. We will try to resolve your issues related to programming assignment and regular assignments.

Best,
Ankur Sharma
31.10.2018

Programming Project: Milestone 1

Dear students,

we just released Milestone 1 of the project. Those of you who already registered their team have been assigned to their repository on Gogs. If you did not register your team yet, do so as soon as possible.

Please read the programming assignment... Read more

Dear students,

we just released Milestone 1 of the project. Those of you who already registered their team have been assigned to their repository on Gogs. If you did not register your team yet, do so as soon as possible.

Please read the programming assignment sheet of Milestone 1 carefully. If you have issues setting up the project, double check that you followed the "Getting Started" section properly. If all fails, visit the forums ;)

You can see your personal progress and that of your fellow students on the evaluation web page. It is updated every day around midnight.

Best of luck,

Immanuel

29.10.2018

Tutorials

Hello students,

Please note that we have our first tutorial today at 10:15. You can find the tutorial slot assigned to you in the CMS.
 
Best regards,
Ankur Sharma
24.10.2018

Tutorials

Hello students,

Please note that the tutorials will start next week. We will finalize 2 tutorials based on your votes, and will inform you about the exact schedule on Friday. Make sure to update your preference for tutorial slot on CMS by tomorrow.

Best,
Ankur Sharma
23.10.2018

Programming LAB

Hello students,

Please note that E2-5, HS001 will host all the programming labs (including today).

Apart from the occasional programming lab, we will offer Office Hours every week on Tuesday, from 14:15 in E1-1 3.06. You can attend this session to clarify any... Read more

Hello students,

Please note that E2-5, HS001 will host all the programming labs (including today).

Apart from the occasional programming lab, we will offer Office Hours every week on Tuesday, from 14:15 in E1-1 3.06. You can attend this session to clarify any doubts related to the course as well as the programming exercises.

Best,
Ankur Sharma
18.10.2018

Tutorial Slots

Hello Students,

We are offering you three choices for tutorials:

Monday: 10:15
Tuesday: 12:15
Wednesday: 12:15
 
Please update your tutorial preferences in the CMS.
 
We plan to offer two tutorial slots in total. Out of the three provided... Read more

Hello Students,

We are offering you three choices for tutorials:

Monday: 10:15
Tuesday: 12:15
Wednesday: 12:15
 
Please update your tutorial preferences in the CMS.
 
We plan to offer two tutorial slots in total. Out of the three provided slots, we will remove the slot with the most number of "Not Okay" votes. After this, we will assign you to one of the two remaining slots according to your preference.
 
Since we have changed the time of our Monday slot due to unavailability of room, please re-check your preference, and update it accordingly.
 
Best,
Ankur Sharma
Show all
 
 

Overview

We are flooded with data be it data on the Web (html pages, twitter, facebook, map services, ...), structured data in databases (your money on bank accounts, addresses, cell phone data, school and uni grades, flight information, taxes, medical records, ...), or data in scientific applications (gene data in bioinformatics, telescope data in astronomy, collider data in physics, measurements of seismic activity in geology, ...).
 
DBMS Core Lecture
The way we access, manage, and process that data has tremendous impact on:
 
  1. performance. Though we sometimes think that a performance problem is due to particular algorithm requiring too much CPU time, it is often the data access patterns and retrieval times that slow down a program. The reason for bad performance may be that data cannot be accessed and shipped fast enough to the CPU. For instance you may be using unsuitable access methods to retrieve a single piece of information from a large data repository. Or you might be using an inefficient data layout ignoring the memory hierarchy and hardware capabilities of modern processors. In addition, even if the data was efficiently retrieved, performance may suffer due to picking the wrong analytical algorithms or not scaling your system correctly.
     
  2. reliability. What happens if your hard disk fails or your data center is flooded with water? How do you make sure that a consistent version of your data is accessible at all times? Can you afford to lose all data? How do you exploit multi-threading for accessing data without corrupting you data repository?

If you are interested in these questions, this might be the right lecture for you. 

In this core lecture you will learn how to answer these questions. You will learn fundamental data managing algorithms and techniques which are used to build (not only) database systems but also search engines (Google), file systems, data warehouses, publish/subscribe systems (like Twitter), streaming systems, map services (google maps), or Amazon's Cloud (EC2), etc. 

These techniques and algorithms will allow you to design, plan, and build (almost) any kind of data managing system.

Administrative / Organisation

When: Thursday 10:15-12:00 (E1 3, HS 002) and Tuesday 14:15-16:00 (E2 5, HS 001) [First introductory lecture on 18.10.2018]
Administrative Details: Available under Information/Materials

Topics

  • data managing architectures (DBMS, file systems)
  • storage media and hierarchies (disk, flash, main memory, caches, NUMA)
  • storage management (DB-file systems, raw devices, write-strategies, differential files, buffer management, RAID, COW, MOW, virtual memory)
  • data layouts (horizontal and vertical partitioning, row stores, columns stores, hybrid mappings, PAX; fractal design, compression, defragmentation)
  • indexing (one- and multidimensional, tree-structured, hash-, partition-based, B-trees, bulk-loading and external sorting, differential indexing, read- and write-optimized indexing, main-memory indexes, covering, composite, sparse and dense, direct and indirect, clustered and unclustered, main memory versus disk and/or flash-based, bitmaps)
  • query processing algorithms (join algorithms for relational, and spatial data, grouping and early aggregation, co-grouping, filtering, external sorting and partitioning)
  • query optimization (query rewrite, cost models, cost-based optimization, join order, plan enumeration)
  • query processing models (operator, interpreted, vectorized, compiled, anti-projection, tuple reconstruction)
  • concurrency control (MVCC)
  • data recovery (single versus multiple instance, logging, main-memory vs disk, ARIES)
  • parallelization of data and queries (horizontal and vertical partitioning, shared-nothing, replication, NoSQL, Apache Spark, Apache Flink)


Privacy Policy | Legal Notice
If you encounter technical problems, please contact the administrators