TLDR: Rosario tests are always pretty hard and detailed, but he curves generously and the workload is manageable.

I agree with most other reviews that the class was pretty chaotic, but it's mainly because it was the first time in 3 years it had been offered and the professor said from the start it would be a "pilot". The workload is super manageable, 4 projects, a midterm, and a final. The midterm is only 15% and it was advertised as a quiz (unfortunately :() but it was a true midterm that requires a fair amount of understanding of everything covered in lecture. I expect our average to be a lot higher on the final given that people likely studied a lot more. If you do take this class, just be aware that Rosario is not very flexible with regrades UNLESS the graders themselves made a mistake. So make sure you follow the specs to a T and ask for clarifications if you aren't sure about something. I actually liked Rosario, I feel like he really cares about his students and he's willing to help you learn if you show him that you are putting in the effort. Maybe an unpopular opinion, but I found him quite funny, a bit sarcastic, but overall a clear lecturer.

prof loves to include trivia on exams, which was true in 143 and still true now (idk what i expected). projects are very, very easy (i have no experience in web dev) but the spec instructions are very unclear and he gets pretty upset if u ask clarifying questions on campuswire (i did not bother, because i took 143 with him and therefore expected this). final scores are not out yet so who knows what my grade is but i don't think it's hard to do well in this class in general, so long as ur willing to tolerate incredibly stupid questions that do not actually test your understanding of underlying principles. the first cs prof ive ever had who lectures on history and expects u to remember names. My god. Are we in middle school. again it's really not tough to remember this but it does make u question the value of ur own time. In my one wild and precious life i'm making sure i wrote down 1996: Opera released in case rosario pulls that one out next

Just save your sanity by not taking this class. He gives out basically an encyclopedia of material and everything is fair game. During lectures he speaks faster than Ben Shapiro and taking any kind of valuable notes impossible. Exams are a coin flip since questions are based on maybe one word he said about a topic in class. Taking a random Udemy class will teach you way more about Web Applications and Web Development than this whole class.

He's not a bad professor, but this class has so much content it is hard to keep up. My issue is that he is often unclear about what's really important for us to learn and what will be on the exams. It makes sense that the concepts that are most important for us to know would be on the exam. However, often times he would have very minuscule facts or edge cases as questions on the exam, as a kind of "gotcha" question that would reference one line on one slide instead of a broad key concept. And in terms of helpfulness, sometimes his Piazza answers would come off as passive-aggressive as if we're coming at him and insulting his knowledge. The homework is pretty doable and sometimes fun to figure out the correct queries. This is a pretty important class for CS majors, so I would take it with Rosario and just thug it out.

This class is arguably the most useful and important class that I have taken at UCLA, joint top along with CS 32. Way more than just a SQL class, Professor Rosario provides a holistic overview of the entire database system. He would often share with us his personal experiences and tips in industry, which I really appreciate since most other professors don't do that. While the first half of the class is mostly focused on SQL and Relational Algebra, the second half includes interesting topics such as Data Warehousing, Streaming Systems and NoSQL. Towards the final parts of the class, we dived even deeper into the hardware aspects, such as data storage, which felt slightly dry at times but definitely integral for those who aim to become data engineers.

Homework assignments were mostly well-crafted and fun to work on, especially Assignments 5 and 6 where we had to write queries in Spark SQL, MongoDB and Neo4j. The only downside of this class is Rosario's fast-paced lectures and tough exams. He goes at the speed of a Shinkansen during lecture, but fortunately he records them so I can re-watch to consolidate my learning. Exams are a time-crunch with never-ending questions, but each question itself is actually not too challenging as long as you are well-prepared.

I was searching for data science internships while taking CS 143, and it has been extremely helpful in tackling SQL interview questions, as well as expanding my knowledge in database systems. Now that I have secured an internship, looking back in hindsight, this class has played a pivotal role in my success. For anyone looking to enter the field of Data Science/Data Engineering/Software Engineering, I would highly recommend this class with Rosario.

Great lecturer and overall good class but bad administration. Like the content is really good. I use it in my job actually. The administration for this class was uhhhh bad. No regrade request for exams, had a really stupid note sheet policy for the midterm and just a bunch of other stupid stuff. I got a point off cause I didn’t show enough work on an assignment graded on completion. Dude also went on a whole rant about how your grade doesn’t define your worth and then proceeded to give a final with like 100 questions. Again though great lecturer and don’t regret taking the class. The grade distribution is also much better than it used to be.

Rosario has a lot of mixed reviews, and you might have similar or very different experiences to these posts. He is a rather perplexing person and goes back and forth in his demeanor. I'll first start talking about the class itself:

The lectures are extremely well put together. It is evident he has put a lot of time into refining them to be both engaging and informative, and he has a lot of examples for things like topological sort, dependencies and normal form, and many more topics. There is A LOT of information covered in this class, mostly in the second half. A lot of it was pretty useful, like learning SQL/NoSQL, transactions, and MapReduce. Some of the stuff we covered, on the other hand, seemed like just a formality and doesn't have real-world value. I recommend skimming through the lecture slides beforehand, and then reviewing a little bit after.

Assignments are, for the most part, interesting and useful, and are good prep for the exams. Some of them were graded on completion (with the caveat of showing ALL your work), and the ones that were graded on correctness usually had an autograder. Specs are somewhat clear, however, if you are unfamiliar with using the terminal (which some people might be if you aren't a CS major), then a couple of the homeworks would be a nightmare.

The exams, however, are really hard. The midterm was not too bad in difficulty, but the grading Rosario used was absolutely ridiculous. You could write a full query that makes sense, and still get 0/18 points because you were missing one thing. The final was hands down the hardest final I've taken at UCLA and most of it was not reflective of what we learned in the class. It stresses a lot of SQL, so you better know how to write good queries going into it. He does grade on a curve, but still it's crazy how much the final was. Multiple people didn't even finish it.

Now I'll talk about Rosario as a professor. He does seem to care about student's in some capacity. He will answer every question in lecture and is pretty approachable in office hours. He is also very active on Piazza and will answer questions with mostly good clarity. He's also understanding when it comes to being a student. However, he can be pretty mean sometimes. There were instances on Piazza when he was rude and unhelpful, and in person he will become extremely defensive when you question his grading, almost to the point of being unprofessional. Yeah, I can understand being dumbfounded when people don't fill in the bubbles on the multiple choice part of the exam even after he talked about it multiple times (I mean it's not that hard to just follow directions), but there's no need to become abrasive when students become worried about their grade. We're all just trying to get by.

TLDR; this class is interesting and useful. Exams are unfair and grading is ridiculously strict, but his curve seems to make up for it. Rosario is for the most part a nice dude, and for the most part is a changed man from the previous reviews, but his old side seems to slip out here and there. If you're looking for an easy elective, this class is not it. Side note: Rosario is seriously accomplished as a person which is insanely impressive.

Class itself is great if you don't have to interact with the professor - he himself is extremely closed-minded and will not tolerate anything that contradicts his beliefs. Examples: no regrade requests allowed at all, extremely harsh grading rubrics on exams where missing a tiny amount of a large problem would cause massive point deductions, and forced the TAs to revert a regrade request giving back points for a problem that was solved correctly.

Ryan sucks. Don't believe all the recent reviews saying he's a "changed man." While he comes off as super friendly and helpful during lecture (he loves to stress how "your mental health as a student is important"), he DOES NOT CARE ABOUT YOU. He obviously has some sort of psychological disorder that causes him to be hyper aggressive towards anyone who questions his authority. I witnessed him behave extremely unprofessionally towards students in the class because he was power tripping. The class also just straight up sucks, the first half is fine but the second half starts delving into information sludge that doesn't even seem helpful at all. The final exam was also the most absurd thing I have ever taken.
My analysis is this: Ryan was bullied as a child (because he is 3 foot 9 and looks like a troll), and now desperately grasps ahold of any modicum of power that this class gives him.

Rosario is a good, dare I say, great professor. I don't know what Rosario these other reviews had when he taught this course. His lectures are full of dense information but he manages to weave in humor and enlightening analogies to make the content digestable. His exams are straightforward and there are no curveballs, his lecture slides contain everything he will test you on. I would take this class again, learned a lot about a wide array of topics concerning databases, which applies to pretty much every CS field. He truly cares about his students and provides them with an abundance of resources to succeed in this class.