COMP3311 Notices

Happy Holidays

Posted by John Shepherd Tuesday 19 December 2023, 08:43:58 AM, last modified Tuesday 19 December 2023, 04:34:48 PM.

Due to a bug in the script to calculate final exam marks, all the submitted exam marks were lower than they should have been by a mark or two. I have fixed the script, recalculated the exam marks, uploaded them into Astra, and this will flow through to final marks in MyUNSW soon.

For most people, this means a couple of extra marks. For some people, it means no extra marks. Nobody will have less marks.

If you were a borderline fail, you may find yourself now a borderline pass. Happy Xmas.

Given the mess I've made of COMP3311 this term, I've decided that CSE would be better off if I stopped teaching courses. Thank you and good night. F**k it. They won't let me leave. Suggestion: avoid any future courses I'm teaching.

Scaling the Final

Posted by John Shepherd Tuesday 05 December 2023, 03:12:53 PM.

Regardless of any petition, I always look at the marks distribution for the final exam. If it looks like it might have been too difficult, I'll scale up. If it looks about right, I won't scale.

Final Exam

Posted by John Shepherd Sunday 03 December 2023, 05:09:30 PM.

The final exam is tomorrow!

Before the exam:

• Get a good night's sleep
• Make sure you know your assigned time and location
• Remember to bring your photo ID (student ID preferred)
  • Driver's licence/passport is a tolerable substitute
• Aim to arrive early

During the exam:

• Use your reading time well
  • Decide what questions you want to tackle first
• Submit as you complete each question
• Keep an eye on how long you're spending on each question
  • Move to another question if spending too long

For the SQL/PLpgSQL/Python questions, you may find it useful to re-use views and functions from earlier questions in answering later questions. Keep in mind that we expect the code for each question to be self-contained. If you want to re-use, copy and paste.

When marking, we create a new database from scratch, load the code for the question, and then run the tests. In the exam, the check script loads the code for the question into the existing database. Not quite the same.

Good Luck.

Exam Database

Posted by John Shepherd Friday 01 December 2023, 04:00:52 PM.

The database for the exam is now available.

Download and explore before Monday to save time in the exam.

Supp Exams

Posted by John Shepherd Saturday 25 November 2023, 12:08:40 PM, last modified Monday 27 November 2023, 01:08:26 PM.

Messages from UNSW about Supp Exams will tell you that Supps are held in the week of Jan 8-12.

CSE lab-based Supp Exams will not be held then. They will be held on Monday 5 Feb 2024 (which is the start of O-week). This includes the COMP3311 Supp Exam. If you have a COMP3311 Supp, you are required to be available to sit the Supp in-person in the CSE Labs in Sydney on that day (Feb 5).

Sample Exams

Posted by John Shepherd Saturday 18 November 2023, 11:55:02 AM.

I will clean up the sample exams today after discovering that several of them had incorrect links.

Please note that the 20T3, 21T3 and 22T3 exams were open-book (open-web), online (done at home) and not invigilated. Given the level of cheating in those exams, CSE will not go back to running exams in that style again in courses where we want some assurance of practical skills (e.g. writing an SQL query).

The 23T1 and 23T3 exams are closed-book, held in the CSE labs, and invigilated. In both cases, we provide access to the Course Notes, and documentation for PostgreSQL, Python3 and Psycogp2.

The 23T1 exam is the closest in style to the 23T3 exam, but all of the exams have similar content.

I will add the 23T1 exam to the Exams page today, while I'm cleaning up other exams.

No more lectures

Posted by John Shepherd Tuesday 14 November 2023, 07:12:07 PM.

There is no lecture on Wednesday 15 November.

I talked about the exam in the Monday lecture if that interests you.

Otherwise, spend the extra two hours working on Assignment 2.

ass2 autotest v3

Posted by John Shepherd Monday 13 November 2023, 11:27:03 PM.

New autotests are now available. Hopefully more correct than yesterday.

I no longer have confidence that they'll be fully correct. Lemme know.

CSE 23T3 In-Person Lab Exam Preference Form Is Now Available For COMP3311

Posted by Dylan Brotherston 🕴️ Monday 13 November 2023, 12:43:30 PM.

A few minutes ago you should have received an email from exam@cse.unsw.edu.au .
This email contains instructions, and a link, for selecting your preferred exam session.
You should check your email and read the full text of the email, but here is the most important part:

The form will be open until 10PM Friday 17th November,
after which no more preferences will be accepted.
(but one or more sessions will likely fill completely long before that time).

Additional information is given on the form, please read all information carefully.

The exact time and location of your exam will be available mid Week 11,
you will receive another email with instructions once it is available.

The preference form is available here:
https://cgi.cse.unsw.edu.au/~exam/23T3/seating/register.cgi

For any questions, please email us at:
<exam@cse.unsw.edu.au>

Ass 2 Deadline

Posted by John Shepherd Monday 13 November 2023, 11:11:23 AM.

Given that vxdb2 was effectively unavailable for around 12 hours yestrday, I've extended the assignment deadline to midday Thursday 16 November.

I will not extended it again based on you overloading vxdb2. Do it now while the load is low.

Also, part of yesterday's problem was /tmp becoming full. PostgreSQL uses /tmp to store large intermediate results. If you write a bad join, which turns into a cross-product, you can produce a very large intermediate table that fills /tmp. If your script seems to be taking a long time (more than 10secs), kill it and hopefully this will clean up /tmp.

autotesting updated

Posted by John Shepherd Monday 13 November 2023, 07:55:51 AM, last modified Monday 13 November 2023, 06:47:12 PM.

I've had another go at the autotesting for ass2. Let me know what's wrong.

Update : I've found bugs in some of the Q5 outputs; will fix after dinner.

I believe that Q5a Q5b Q5g Q5h Q5i have correct output. The rest definitely don't.

Week 10 and vxdb2

Posted by John Shepherd Sunday 12 November 2023, 09:36:04 PM.

The Week 10 Preview video is now available. Worth a look, I think.

Since you've managed to kill vxdb2, I've asked the Systems Support people to reboot it.

Don't know when that will happen.

But vxdb2 became effectively useless at around 5pm Sunday.

When it comes back, I'll add however many hours it takes to get rebooted onto the deadline.

vxdb2 Overloaded

Posted by John Shepherd Sunday 12 November 2023, 05:11:50 PM.

There are currently 155 users and 762 PostgreSQL servers running on vxdb2.

The load is very high and is causing problems with autotest (among other things).

Please shut down your PostgreSQL server when you've finished using it.

Buggy acadobjs strings

Posted by John Shepherd Sunday 12 November 2023, 04:42:01 PM.

A couple of requirements have a buggy acadobjs string. They can be fixed by running this SQL command in your own ass2 database:

update requirements
set acadobjs = replace(acadobjs,'COMP9##,GSOE92###','COMP9###,GSOE92##')
where acadobjs ~'COMP9##,GSOE92###';

I've also fixed this in ~cs3311/web/23T3/assignments/ass2/files/ass2.dump.

Depending on how implemented course code pattern checking, this may or may not have affected you.

Q5 autotest

Posted by John Shepherd Sunday 12 November 2023, 03:36:22 PM.

First attempt at Q5 autotest is now available. Let me know what's wrong.

I've left white-space checking turned off.

autotest

Posted by John Shepherd Friday 10 November 2023, 01:55:55 PM, last modified Friday 10 November 2023, 03:53:35 PM.

My first attempt at auto-testing is now available

3311 autotest ass2

Let me know what's not working.

Update : fixed the bugs in the first attempt

P.S. The original error in the Q2 output (missing allcourseinfo ) was a good example of what happens if you have views in your database that are not in helpers.sql . If they're not in helpers.sql they won't be loaded into the database that we create for testing. Don't make this mistake.

Patch to ass2 Database

Posted by John Shepherd Thursday 09 November 2023, 03:07:22 PM.

If you want your output for e.g.q3-5 to be consistent with the Examples page, then run this statement in a psql ass2 session:

update requirements set min_req=66 where id in (319,321,323,325,327,322,318);

It changes all of the Computer Science streams from program 3778 to have the correct Total UOC value (66 rather than 96).

COMP3311 Exam

Posted by John Shepherd Monday 06 November 2023, 04:45:45 PM.

Just got info on the precise times for the exam sessions:

Monday 4th December

Morning: 10:15 - 13:30

Afternoon: 13:55 - 17:10

You only need to attend one of these sessions. There will shortly be a form to register preferences.

Help Sessions

Posted by John Shepherd Monday 06 November 2023, 01:22:01 PM, last modified Monday 06 November 2023, 01:24:20 PM.

Reminder: there are Help Sessions for COMP3311 at the following times:

• Mon 12-2, Tue 2-4, Thu 10-12, Fri 10-12

Ground floor, K17

Week 09

Posted by John Shepherd Sunday 05 November 2023, 09:10:20 PM.

The week 09 preview video is now available.

In the Monday lecture, I'll run through some examples of Ass2/Q5.

Assignment 2 Fixes

Posted by John Shepherd Thursday 02 November 2023, 06:06:17 PM, last modified Saturday 04 November 2023, 04:20:57 PM.

Make sure that you keep checking the Fixes+Updates page for the Assignment.

If people find bugs/inconsistencies in the spec or examples, I'll fix them and document them in the Fixes+Updates page.

Deadline for Quiz 5

Posted by John Shepherd Thursday 02 November 2023, 08:19:29 AM.

I just noticed that I'd set the deadline for Quiz 5 to Saturday 11:59, but all week I've been announcing Friday 11:59. I'll leave it on Saturday; changing to Friday now would no doubt elicit howls of protest. The release of solutions will still be Monday 9am.

Demonstrating SQL Injection

Posted by John Shepherd Wednesday 01 November 2023, 10:04:35 PM.

One of your colleagues (Nicholas Langford) has written a web app for his COMP6841 project.

https://nlangford-vulnerable-<wbr>webapp-7f65a6cee144.herokuapp.<wbr>com/

As he says "My project is an intentionally vulnerable webapp for teaching cybersecurity. Its aim is to make cybersecurity less overwhelming for beginners by guiding them through basic web attacks, starting with SQL injection."

The app is not doing anything suspect. If you try it out, send Nicholas some feedback.

Assignment 2

Posted by John Shepherd Tuesday 31 October 2023, 07:35:53 PM, last modified Tuesday 31 October 2023, 10:16:07 PM.

Finally(!), I've finished the database and most of the specification .

How to get the database is described in the spec.

All that remains is to produce some sample output. Tonight.

As usual, let me know ASAP if anything is ambiguous, unclear or inconsistent.

Update : found first bug ... wrong dbname in supplied q?.py files ... keep track of these in the Fixes+Updates page.

Assignment 2 Database and Schema

Posted by John Shepherd Wednesday 25 October 2023, 07:41:59 AM.

As always, I underestimated how long it would take to build the database.

The database should be ready by Thursday and the specification by Friday.

Assignment 1 provisional performance marks

Posted by Dylan Brotherston 🕴️ Saturday 21 October 2023, 12:24:56 PM.

Hi everyone,

Assignment 1 provisional performance marks are now available.

You can either run the command `3311 classrun -collect ass1` on a CSE server,
or view your results in webCMS in the Collect Submission Tab.

These marks have not yet been reviewed by tutors, so marks could change.
And the 2 style marks have not been assessed yet.

If you have an extension for Assignment 1 your marks will not be available yet.

Week 05 Lecture Videos

Posted by John Shepherd Thursday 19 October 2023, 12:59:30 PM, last modified Thursday 19 October 2023, 01:00:28 PM.

I've replaced the dud Wednesday video by one where I grafted the Echo360 audio track into my Video. It was difficult to get the lip sync exactly right, so in places it looks like a poorly dubbed movie. Close enough.

While I was fixing the Wednesday video, I accidentally deleted the Monday video from YouTube. I've put it back, but it has a different URL, if you happen to collect URLs. Accessing it through the Webcms3 Lectures page works fine after I fixed the link there.

Q6

Posted by John Shepherd Friday 13 October 2023, 07:15:01 AM.

The auto-test answers for Q6 are correct. Write your code to pass them.

The assumption, which I thought I had put in the spec, is that collab beers are brewed at each brewery in the collaboration and therefore get counted multiple times.

Quiz 3 Q1

Posted by John Shepherd Wednesday 11 October 2023, 02:52:14 PM.

A few people have mentioned that option (e) should also be a correct answer.

It my be that I just forgot to check (e) as correct when setting up the quiz.

I'll check, and adjust all the marks if this indeed the case.

Week 05 Preview

Posted by John Shepherd Sunday 08 October 2023, 09:28:47 PM.

The Week 05 Preview Video is now available.

Note the comments about Assignment 1, especially if you haven't started yet.

COMP3311 Help Sessions

Posted by John Shepherd Thursday 05 October 2023, 09:13:40 AM.

For at least Weeks 4 and 5, there will be COMP3311 help sessions in K17-G05

Mon 12-2, Tue 2-4, Thu 10-12, Fri 10-12

Many problems are best resolved in person. Please make use of the sessions.

Week 04 Monday Lecture

Posted by John Shepherd Monday 02 October 2023, 06:09:38 PM.

I made a video to replace today's live lecture. It's on YouTube already, and I'll put it on Ech360 as well.

Week 04

Posted by John Shepherd Sunday 01 October 2023, 10:56:03 PM.

The Week 04 Preview video is now up.

One thing I forgot to mention is that it's HECS Census next weekend. If you think you might want to drop this course, and you don't want to pay for it, drop it before Sunday 8 October.

Ass1 Autotesting

Posted by John Shepherd Saturday 30 September 2023, 04:51:10 PM.

Autotesting is set up. To use it:

• login to vxdb2 and run your PostgreSQL server
• change into the directory containing your ass1.sql
• run the command 3311 autotest ass1

Let me know if the above instructions don't work.

The tests include all of the tests in the Examples files, plus a couple more.

COMP3311 Help Sessions

Posted by John Shepherd Thursday 28 September 2023, 10:03:24 AM.

Each week, we'll have (at least) two Help Sessions for COMP3311.

Thursday 10-12, Friday 10-12

I'll try to schedule more earlier in the week.

All sessions are in K17-G04 (CSE Help!)

Quiz 2 errata

Posted by John Shepherd Tuesday 26 September 2023, 04:03:46 PM.

There was an uniententional "error" in one option from Question 2.

If you're one of 100 or so people who've already submitted the quiz, you might want to take another look at that question. You can always re-submit.

Week 03 Preview

Posted by John Shepherd Sunday 24 September 2023, 09:02:42 PM.

The Week 03 Preview Video is now up.

Assignment 1 (iii)

Posted by John Shepherd Sunday 24 September 2023, 03:13:07 PM.

All the questions are done. Please read the questions, look at the examples, and ask for clarification if anything looks unclear/ambiguous/inconsistent/wrong.

Once you've inserted views, don't just them against the supplied examples. Try other cases, and check them by asking alternative queries on the database.

I'll answer questions in the forum and do a Q&A session in the lecture on Monday 2 October.

Assignment 1 (ii)

Posted by John Shepherd Thursday 21 September 2023, 11:37:28 PM, last modified Friday 22 September 2023, 11:03:52 AM.

I've added some of the questions, and example outputs. I'll finish the rest on Friday morning.

I also found a couple of minor bugs in the database, and I've fixed those. You'll need to rebuild your database using the new ass1.dump, i.e.

dropdb ass1; createdb ass1; psql ass1 -f ~cs3311/web/23T3/assignments/ass1/ass1.dump

And, of course, let me know if anything ambiguous or inconsistent.

Update : there was a buggy ass1.dump file for a few hours on Friday morning. The copy from 10:56 (the current one in the assignment directory) is the one to use.

Help Sessions

Posted by John Shepherd Thursday 21 September 2023, 04:30:54 AM.

We'll be running Help Sessions for getting your PostgreSQL server running and your Assignment 1 database set up, in the CSE Help! space (K17 Ground floor) on Thursday 10-12 and Friday 10-12

Assignment 1

Posted by John Shepherd Tuesday 19 September 2023, 10:08:14 PM, last modified Wednesday 20 September 2023, 10:25:12 AM.

The first tranche of material for Assignment 1 is now available. It contains a partial specificiation (no questions yet) and a description of the database. You should be able to create and load the database, and explore it.

I'll add the questions and examples and testing info on Wednesday Thursday evening.

In the meantime, here are some queries from earlier tems for you to try

• names and suburbs of breweries in Sydney founded since 2020
• info on beers whose name is the same as their style name
• info on beers which have "IPA" somewhere in their style name
• what is the most frequently used hop variety?
• what is the grain most often used in Hazy IPAs?

Week 02 Preview

Posted by John Shepherd Sunday 17 September 2023, 08:06:10 PM.

The Week 02 Preview video is now up.

It has a lot of useful information that I won't be repeating in lectures.

Video of Lecture

Posted by John Shepherd Monday 11 September 2023, 05:45:27 PM, last modified Sunday 17 September 2023, 04:06:39 PM.

The audio on the Echo360 video is hopeless (too soft). The audio on the YouTube video is much better. I'll need to get CATS to look at the crappy state of the microphones in CLB7. And I'll see if I can get the audio on the Echo360 version enhanced.

The YouTube video is now available. Much better audio.

Course Overview Video

Posted by John Shepherd Sunday 10 September 2023, 06:27:40 PM, last modified Monday 11 September 2023, 08:27:12 AM.

I've now added the Course Overview video , which essentially replaces the stuff I would have said in the first lecture (back in the days when we had 12-week semesters).

Treat it as an adjunct to the Course Outline. It would be useful to watch before the first lecture, or, at least, sometime early in Week 1.

Welcome Video

Posted by John Shepherd Friday 08 September 2023, 11:59:31 AM.

It required some gaffer tape, but the Welcome video is done.

Next up, a Course Overview video, telling you what's in the course and how it runs.

In the meantime, there are some Polls already running. Please respond.

"online" Lectures

Posted by John Shepherd Thursday 07 September 2023, 09:44:27 AM.

Yet another timetable stuff-up. It gives the impression that lectures will be live-streamed at the same time as the live lectures. This is not the case.

If you don't attend the live lecture, you can watch the Echo360 or YouTube video of the live sesion.

Tutorials start in Week 2

Posted by John Shepherd Thursday 07 September 2023, 06:35:45 AM, last modified Friday 08 September 2023, 10:50:59 PM.

Despite what the (grrr) UNSW timetable says, we will not be running COMP3311 tutorials in week 1.

Tutorials start from Week 2.

Update:

Good news, the UNSW timetable should now be updated to correctly show that tutorials start from Week 2.

Welcome to Databases 23T3

Posted by John Shepherd Thursday 07 September 2023, 06:33:34 AM.

The new season the databases adventure kicks off on Monday (Sept 11) at 2pm in OShane 104, the theatre formerly known as CLB7. I look forward to to seeing the theatre full, and will be offering Chupa Chups to the best questions from the audience.

The "Welcome" video is currently under production, but director (and star) has been unwell for the last few days.