Ανακοινώσεις μαθήματος Advanced topics in databases (Προηγμένα Θέματα Βάσεων Δεδομένων, ΗΜΜΥ)

Presentations for Assignmnet will start at 14.30 on Wednesday 27/05

Tue, 26 May 2026 14:52:06 +0300

Dear all, due to a tragic incident I am forced to postpone tomorrow's assessment of assignment 4 for a few hours. Specifically, we will start at 14:30 at the same place as usual. I am sorry for this last minute announcement and any inconvinience it may be causing.

In case some of you have made other arrangements, I am willing to examine theit work on Thursday provided that I am informed accordingly and in time. As for the deadline for submitting your works, it remains the same.

Assignment 4

Mon, 25 May 2026 12:04:54 +0300

Dear all this is a reminder of the upcoming deadline for assignmnet 4 and the presentation of submitted works in class on Wednesday, May 27. Kindly respect the deadline and the assignment's requirements.

Reference textbooks - Αφορά μόνο δικαιούχους του ΗΜΜΥ

Tue, 12 May 2026 20:53:11 +0300

Δείτε την παρακάτω ενημέρωση απο την ιστοσελίδα του τμήματος:

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Η καταληκτική ημερομηνία για τη δήλωση των συγγραμμάτων του εαρινού εξαμήνου από τους φοιτητές είναι η Παρασκευή 15 Μαΐου 2026. Επίσης, σημειώνουμε ότι η καταληκτική ημερομηνία για τη διανομή των συγγραμμάτων στους φοιτητές είναι η Παρασκευή 29 Μαΐου 2026. Παρακαλούνται όσοι φοιτητές δεν το έχουν κάνει ακόμη, να δηλώσουν και στη συνέχεια να παραλάβουν έγκαιρα τα συγγράμματά τους από τα σημεία διανομής.

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Schedule for upcoming lectures and assignments

Tue, 12 May 2026 20:46:23 +0300

Dear all,

I have tried to finalize the schedule for the remaining weeks of the course, both in terms of content and assignments pending. I have also started to populate the folders with indicative material, mainy recommended reading, and I will continue to do so as time goes by. Please take a look and let me know if the deadlines are appropriate (especially for ERASMUS students). As you will see the idea is to have everything sorted out before the June examination period. I would also recommend that you consider assignments 4 and 5 as (potentially) one unit, irrespective of the deadlines set, so that decisions and commitments made for assignment 4 will stand valid for assignment 5.

Assignment 3 - Reminder

Tue, 05 May 2026 09:22:44 +0300

Dear all,

This is a reminder that Assognment 3 is due on Wednsday morning. You should also pick a slot from the sheet for in class presentation.

Slides on JSON/XML data types and inheritance

Wed, 29 Apr 2026 14:41:05 +0300

I have just uploaded the slides on JSON / XML data types and inheritance

Assignment 3 - Revisions

Wed, 29 Apr 2026 10:18:03 +0300

Dear all,

Regarding the upcoming assignment 3, I would like to inform you of a revision in two of the four cases released this semester, namely ClassNet and Auctions. The revision is due to the fact that in these two case studies there is no question/requirement addressing the use of JSON/XML data type. Consequently, students working on these two case studies should additionally consider the following:

In at least one of the subclasses of the specialization hierarchy, there should be a column attribute named profile of type JSON or JSONB to store data (of your choice) relevant to the subclass. In populating the column with data provisions should be made so that the profile column contains (at least one instance of) nested array. Then, example queries should be presented to demonstrate:

Checking Existence of certain key within the JSON structure
Simple filtering using the containment operator and complex filtering with JSONPath
Adding, updating, or removing items from arrays within the JSON structure

Comment on Assignment 2

Mon, 27 Apr 2026 13:22:51 +0300

Dear all,

This is to inform you that over the weekend I managed to collect all missing materials (from students with partial submissions) and complete the assessment of assignment 2. As indicated in my previous announcement, your efforts have been quite appropriate and I am planning to give you all full marks to make up for lost ground in assignment 1. One note/remark, I need to make is that, I now realized that assignment 2 did not have explicit questions on multi-dimensional arrays and nested data types. I am sorry about this which was due to the fact that I had to prepare so many different cases and this led to missing out certain details.

In terms of forthcoming work, you already have assignment 3 running which means that you have an idea of what is to be done. I am preparing / finalizing the slides on JSON/XML data types and inheritance which I expect to release by the coming Wednesday. Until then, I have uploaded some reference material for your consideration.

Finally, I will reiterate once more that I need you to follow the instructions of the assignments and submit the needed materials so that I can check the scripts and avoid delays.

All the best.

Reminder of Assignment 2 and schedule of in-class presentation

Mon, 20 Apr 2026 12:53:18 +0300

Dear all,

I hope you have had a relaxing Easter holiday and that you are all back (or due to be back) in circulation.

This is a gentle reminder of the deadline for Assignment 2 which is getiing close. You should therefore upload your material in time and declare a slot (see sheet) to present your work in class.

PS. As assignment 2 is more development-oriented your in-class presentation (and any supporting material) should aim to justify design decisions you have made in your code extracts. Please do not forget to upload a zipped file containing both presentation/document materials as well as the Postgres code (.sql file).

Reminder for deadline of Assignment 1 and in-class presentations

Tue, 24 Mar 2026 11:10:39 +0300

Dear all, this is a friendly reminder for assignment 1 deadline (shortly) and in-class presentations (starting as 14:00). You are kindly informed that there will be no extension or acceptance of email submissions (before or after the deadline). It is also important to pay attention to the recently circulated guidelines for preparing your submissions. Finally, you are all advised to attent today's in-class presentations (in 5PK, 1st floor above the ERASMUS office) and in any case make your selves available in advance of your declared time slot.

Guidelines for assignment preparation and submission

Thu, 19 Mar 2026 21:25:08 +0300

For all assignments in this course students should deliver / upload to eclass a zipped file containing:

an extended abstract (2 page maximum) which will summarize the student's work in each assignment
powerpoint presentation of the students work during the assignment which is presented in class
any code / scripts as needed

Guidelines for extended abstracts and presentations:

The abstract should have an appropriate title, the student's name, the main section (reflecting on the primary challenge in each assignment, how are these challenges approached in terms of related theory and methods and what the results are).

For in-class presentation, use an appropriate powerpoint template to explain / elaborate on the extended abstract by focusing on details that aim to convince the audience of the work carried out and how it addresses the issues / challenges set.

Case studies selection

Thu, 19 Mar 2026 20:59:59 +0300

Although the message concerns only the ERASMUS students, you should all be aware that teamwork is not foreseen in this course, especially for students not attending lectures. On the issue of selecting case study, I have already discussed it with the home students and they have made their choices. Unfortunately, I cannot satisfy further requests for additional case studies (expressed by some ERASMUS students) at this advanced point in the course. As a result and only for the registered ERASMUS students who contacted me by email, I will accept individual assignments on the same case study, on the understanding that each assignment will reflect the student's own work (rather than the work of another or joined work) and I will make sure to check on this during the in-class presentations. Needless to say that unfair efforts will cause disqualification of the parties involved.

ClassNet case study updated

Thu, 19 Mar 2026 10:13:56 +0300

This is to inform you that the additional case study (ClassNet) has been updated, both in the description of the problem and the scripts to be used. Please, refer to the current version for your course work.

New case study available

Thu, 19 Mar 2026 00:02:24 +0300

Dear all, as there have been four home and four ERASMUS students registered for presentations on Assignment 1, I have updated the case studies section so that there is now an additional fourth case available for your consideration. In terms of scripts and data, the last case (ClassNet) remains to be finalized and checked but the section on Assignment 1 is complete. Please make sure that you do not pick the same case as that of your colleagues (since group work is not acceptable) and update the Google spreadsheet accordingly. By tomorrow, I hope to have everything updated and sorted out.

Time schedule for Assignmnet 1

Wed, 18 Mar 2026 14:31:07 +0300

Kindly pick the time slot that is best for you from the link

Case studies and initial study material

Thu, 05 Mar 2026 10:28:52 +0300

Dear all, I have started populating the course in eclass with relevant material. Specifically, you will find three case studies from which you will pick one to work throughout the semester. The specific deadlines for the assignments will be announced in due course but you can find a tentative schedule in the subfolders of the course. Kindly notice that the material and the schedule for assignments are common for home and ERASMUS students which means that you should be prepared to present your assignments in class to a mixed audience. I hope the above creates a baseline for us all and I look forward to be working with you on this course.

Spring semester 2025-26 (Welcome note)

Tue, 24 Feb 2026 09:59:35 +0300

Dear all,

As I have noticed ERASMUS students being registered for the course I will make this first announcement in English to ensure that we all start from the same baseline.

I welcome you all to the course and I wish to make the following clarifying remarks in the light of tommorrow's kick-off lecture.

First of all, you should be aware that the course is available to students in three programs of studym namely, ECE students (who attend classes and are examined at the end of the course), Informatics Engineering students (being only examined at the end of the course) and ERASMUS students who may chose to work at a distance (ERASMUS students should come to see me for a quick discussion on pre-requisites).

I will make every effort to provide informative guidance to all of you by clearly stucturing, marking and clustering relevant material and course announcements. For those of you who wish to make a contact they can use my email (da@hmu.gr) or meet me at my office (istlab, next to Lab 5PK on the first floor above the ERASMUS office)

Φοιτητές στο Προγ. Σπουδ. Μηχ. Πληρ. (Συμμετοχή στις εξετάσεις)

Tue, 10 Jun 2025 10:01:06 +0300

Καλημέρα σε όλες και όλους.

Με εξαίρεση τον φοιτητή με ΤΠ5056 (που δεν υπέβαλε τον κώδικα γισ το mini-project του) όλοι οι υπόλοιποι ολοκληρώνετε επιτυχώς το εργαστηριακό σκέλος του μαθήματος και έχετε δικσίωμσ συμμτοχής στην τελική εξέταση (όπως προβλέπεται στο πρόγραμμα της εξεταστικής του Ιουνίου που έχει ανακοινωθεί).

Παρακαλώ λάβετε υπόψη σας τα ακόλουθα:

Οσοι έχετε αποκτήσει δικαίωμα εξέτασης και δεν προσέλθετε στην τελική εξέταση του Ιουνίου ή δεν την ολοκληρώσετε επιτυχώς μπορείτε να προσέλθετε τον Σεπτέμβρη χωρίς υποχρέωση (νέας) υποβολής mini-prpject. Αν και τότε δεν προσέλθετε ή δεν ολοκληρώσετε επιτυχώς την εξέταση τότε θα πρέπει να επαναλάβετε το μάθημα απο την αρχή (με νέο mini-project) την επόμενη φορά που το μάθημα θα δοθεί στο πρόγ. σπουδ. του ΗΜΜΥ
Οσοι δεν αποκτήσσατε δικαίωμα εξέτασης τον Ιούνιο θα πρέπει να υποβάλλετε εκ νέου βελτιωμένο το miniproject σας για έλεγχο και πιθανή συμμετοχή στην εξεταστική του Σεπτεμβρίου.
Η τελική βαθμολογία για το μάθημα θα υποβληθεί μετά το πέρας της τελικής εξέτασης.

Καλή συνέχεια και καλή επιτυχία σε όλες και όλους.

Για τους φοιτητές του Προγ. Σπουδ. Μηχ. Πληρ.

Wed, 04 Jun 2025 10:30:32 +0300

Καλημέρα σας.

Θα ήθελα να σας ενημερώσω οτι εκπρόθεσμη υποβολή mini-project δεν μπορεί να γίνει δεκτή. Αυτό που μπορεί να συμβεί είναι οι φοιτητές που είναι εγγεγραμμένοι να υποβάλουν εκ νέου τo mini-project τους και αν κριθεί ικανοποιητικά να συμμετέχουν στην εξεταστική του Σεπτέμβρη.

Αναφορικά με την τελική εξέταση, βρίσκομαι στη διαδικασία ελέγχου των εμπρόθεσμων υποβολών και μέχρι την ερχόμενη Παρασκευή θα υπάρξει σχετική ανακοίνωση.

Η τελική εξέταση είναι προγραμματισμένη για την 16/06.

Καλή συνέχεια.