title
01 - Relational Model & Relational Algebra (CMU Intro to Database Systems / Fall 2022)

description
Andy Pavlo (https://www.cs.cmu.edu/~pavlo/) Slides: https://15445.courses.cs.cmu.edu/fall2022/slides/01-introduction.pdf Notes https://15445.courses.cs.cmu.edu/fall2022/notes/01-introduction.pdf 15-445/645 Intro to Database Systems (Fall 2022) Carnegie Mellon University https://15445.courses.cs.cmu.edu/fall2022/

detail
{'title': '01 - Relational Model & Relational Algebra (CMU Intro to Database Systems / Fall 2022)', 'heatmap': [{'end': 1434.127, 'start': 1331.317, 'weight': 0.947}, {'end': 2008.325, 'start': 1957.899, 'weight': 1}, {'end': 2632.209, 'start': 2577.456, 'weight': 0.907}], 'summary': "Covers dj mushu's visit, database lecture logistics, plagiarism policy, database design challenges, evolution of databases, query optimization, relational model, set theory, join operators, and query optimization in sql and relational algebra.", 'chapters': [{'end': 86.589, 'segs': [{'end': 86.589, 'src': 'embed', 'start': 23.29, 'weight': 0, 'content': [{'end': 25.471, 'text': 'I have not taught this class in a while.', 'start': 23.29, 'duration': 2.181}, {'end': 26.991, 'text': "So it's good to be back.", 'start': 25.491, 'duration': 1.5}, {'end': 29.072, 'text': 'Everybody is very supportive and appreciative.', 'start': 27.051, 'duration': 2.021}, {'end': 31.552, 'text': 'Whoever gave me the mixtape, thank you.', 'start': 30.132, 'duration': 1.42}, {'end': 32.253, 'text': "I'll listen to this later.", 'start': 31.572, 'duration': 0.681}, {'end': 36.014, 'text': "So I'll give a round of applause for our DJ, DJ Mushu.", 'start': 33.433, 'duration': 2.581}, {'end': 41.935, 'text': 'So Mushu is the illest DJ in Pittsburgh.', 'start': 39.354, 'duration': 2.581}, {'end': 43.516, 'text': 'So I want you to show what you can do.', 'start': 42.115, 'duration': 1.401}, {'end': 43.836, 'text': 'Let her ring.', 'start': 43.556, 'duration': 0.28}, {'end': 44.996, 'text': 'All right.', 'start': 44.676, 'duration': 0.32}, {'end': 58.157, 'text': 'Do you want me to stop? Yeah, I can teach you slaps.', 'start': 53.834, 'duration': 4.323}, {'end': 63.561, 'text': 'Mooshio is the hottest unsigned artist in Pittsburgh.', 'start': 58.657, 'duration': 4.904}, {'end': 65.903, 'text': "We're really appreciative of him being here.", 'start': 63.581, 'duration': 2.322}, {'end': 68.364, 'text': "How are things, man? I'm good.", 'start': 66.363, 'duration': 2.001}, {'end': 74.709, 'text': "I'm just here to drop some dang beats, but I'm surprised you're still in Pittsburgh.", 'start': 68.384, 'duration': 6.325}, {'end': 76.59, 'text': 'Yes, it is true.', 'start': 75.89, 'duration': 0.7}, {'end': 77.471, 'text': 'I did have a rough summer.', 'start': 76.61, 'duration': 0.861}, {'end': 81.253, 'text': "I haven't talked in a while.", 'start': 77.491, 'duration': 3.762}, {'end': 83.155, 'text': 'My ex-wife..', 'start': 82.494, 'duration': 0.661}, {'end': 85.388, 'text': 'a year ago.', 'start': 84.827, 'duration': 0.561}, {'end': 86.589, 'text': 'Still healing up.', 'start': 85.968, 'duration': 0.621}], 'summary': 'Dj mushu is the illest dj in pittsburgh. mooshio is the hottest unsigned artist. the speaker had a rough summer.', 'duration': 63.299, 'max_score': 23.29, 'thumbnail': 'https://coursnap.oss-ap-southeast-1.aliyuncs.com/video-capture/uikbtpVZS2s/pics/uikbtpVZS2s23290.jpg'}], 'start': 23.29, 'title': "Dj mushu's visit", 'summary': "Discusses dj mushu's visit to pittsburgh, where he is praised as the illest dj and hottest unsigned artist, and he mentions having had a rough summer and still healing from his previous marriage.", 'chapters': [{'end': 86.589, 'start': 23.29, 'title': "Dj mushu's visit", 'summary': "Discusses dj mushu's visit to pittsburgh, where he is praised as the illest dj and hottest unsigned artist, and he mentions having had a rough summer and still healing from his previous marriage.", 'duration': 63.299, 'highlights': ['DJ Mushu is praised as the illest DJ in Pittsburgh and the hottest unsigned artist.', 'DJ Mushu mentions having had a rough summer and still healing from his previous marriage.', "The chapter discusses DJ Mushu's visit to Pittsburgh."]}], 'duration': 63.299, 'thumbnail': 'https://coursnap.oss-ap-southeast-1.aliyuncs.com/video-capture/uikbtpVZS2s/pics/uikbtpVZS2s23290.jpg', 'highlights': ['DJ Mushu is praised as the illest DJ in Pittsburgh and the hottest unsigned artist.', 'DJ Mushu mentions having had a rough summer and still healing from his previous marriage.', "The chapter discusses DJ Mushu's visit to Pittsburgh."]}, {'end': 497.524, 'segs': [{'end': 143.418, 'src': 'embed', 'start': 115.568, 'weight': 0, 'content': [{'end': 119.149, 'text': "They're paying for extra TAs and course development throughout the entire semester.", 'start': 115.568, 'duration': 3.581}, {'end': 126.253, 'text': "If you've never heard of Snowflake before, they are a distributed cloud data OLAP vectorized data warehouse.", 'start': 119.169, 'duration': 7.084}, {'end': 131.375, 'text': "And if everything I said there doesn't make sense, that's OK, because you'll learn all these things throughout the semester.", 'start': 126.753, 'duration': 4.622}, {'end': 133.947, 'text': 'All right.', 'start': 132.705, 'duration': 1.242}, {'end': 136.61, 'text': 'And so they will be giving a guest lecture at the end of the semester.', 'start': 134.207, 'duration': 2.403}, {'end': 140.334, 'text': 'They will also have internships available for senior students.', 'start': 136.63, 'duration': 3.704}, {'end': 143.418, 'text': "And I'll post all this on Piazza, how to apply and talk to them.", 'start': 140.735, 'duration': 2.683}], 'summary': 'Snowflake offers extra tas, course development, guest lecture, and internships for senior students.', 'duration': 27.85, 'max_score': 115.568, 'thumbnail': 'https://coursnap.oss-ap-southeast-1.aliyuncs.com/video-capture/uikbtpVZS2s/pics/uikbtpVZS2s115568.jpg'}, {'end': 187.094, 'src': 'embed', 'start': 153.49, 'weight': 4, 'content': [{'end': 154.97, 'text': 'The other thing I wanna pick up too,', 'start': 153.49, 'duration': 1.48}, {'end': 160.492, 'text': "about the course throughout the entire semester is that you need to understand where I'm coming from as I teach databases.", 'start': 154.97, 'duration': 5.522}, {'end': 165.854, 'text': 'And the most important thing you have to understand is I really only care about two things in my entire life.', 'start': 161.292, 'duration': 4.562}, {'end': 169.535, 'text': 'The first one is my wife and my biological daughter.', 'start': 167.054, 'duration': 2.481}, {'end': 171.736, 'text': 'And the second one is databases.', 'start': 170.055, 'duration': 1.681}, {'end': 173.476, 'text': "So I really don't have any other hobbies.", 'start': 172.036, 'duration': 1.44}, {'end': 175.957, 'text': 'It is just pathologically focused on databases.', 'start': 173.716, 'duration': 2.241}, {'end': 179.622, 'text': 'And so if you ask me any questions about database, I might be able to answer it.', 'start': 176.497, 'duration': 3.125}, {'end': 187.094, 'text': "Some questions will be appropriate for the class and some we do after class, but I'm happy anytime to talk about databases.", 'start': 180.083, 'duration': 7.011}], 'summary': 'In teaching databases, the instructor is solely focused on his family and databases, with no other hobbies, and is open to answering questions.', 'duration': 33.604, 'max_score': 153.49, 'thumbnail': 'https://coursnap.oss-ap-southeast-1.aliyuncs.com/video-capture/uikbtpVZS2s/pics/uikbtpVZS2s153490.jpg'}, {'end': 241.932, 'src': 'embed', 'start': 209.271, 'weight': 1, 'content': [{'end': 212.453, 'text': "So if you've probably noticed, the waitlist is massive this semester.", 'start': 209.271, 'duration': 3.182}, {'end': 213.814, 'text': 'I think we got to like 450.', 'start': 212.473, 'duration': 1.341}, {'end': 218.177, 'text': "We're like in third or fourth place in terms of the longest waitlist in the university.", 'start': 213.814, 'duration': 4.363}, {'end': 221.079, 'text': "It's some ML class, then English, and then I think us.", 'start': 218.637, 'duration': 2.442}, {'end': 223.621, 'text': "So I don't control the waitlist.", 'start': 222.38, 'duration': 1.241}, {'end': 225.542, 'text': 'We can only take 120 students.', 'start': 224.161, 'duration': 1.381}, {'end': 231.847, 'text': "The waitlist got so large that the SCS admins took over it, and I can't control who's actually admitted anymore.", 'start': 227.123, 'duration': 4.724}, {'end': 236.07, 'text': 'So the admins will put people off the waitlist and enroll them as new spots become available.', 'start': 232.487, 'duration': 3.583}, {'end': 241.932, 'text': "Just to be honest, though, at this point, if you're not enrolled in the class, you're very unlikely to get in.", 'start': 236.71, 'duration': 5.222}], 'summary': 'Class waitlist reached 450, only 120 spots available, admins managing admissions.', 'duration': 32.661, 'max_score': 209.271, 'thumbnail': 'https://coursnap.oss-ap-southeast-1.aliyuncs.com/video-capture/uikbtpVZS2s/pics/uikbtpVZS2s209271.jpg'}, {'end': 353.246, 'src': 'embed', 'start': 327.17, 'weight': 2, 'content': [{'end': 334.187, 'text': 'okay?, All right, so this class is entirely about the design and implementation of database management systems.', 'start': 327.17, 'duration': 7.017}, {'end': 337.771, 'text': "In my opinion, that's the most important class of software that exists in the world today.", 'start': 334.667, 'duration': 3.104}, {'end': 341.415, 'text': "And that's why there's an entire class specifically about it.", 'start': 337.791, 'duration': 3.624}, {'end': 346.421, 'text': 'So this course would not be how to use a database or design an application to use a database.', 'start': 342.617, 'duration': 3.804}, {'end': 348.523, 'text': 'That is taught in Heinz College.', 'start': 347.142, 'duration': 1.381}, {'end': 353.246, 'text': "You'll get exposure to SQL in the first assignment for the first homework.", 'start': 349.423, 'duration': 3.823}], 'summary': 'Class focuses on database management systems, sql covered in first assignment.', 'duration': 26.076, 'max_score': 327.17, 'thumbnail': 'https://coursnap.oss-ap-southeast-1.aliyuncs.com/video-capture/uikbtpVZS2s/pics/uikbtpVZS2s327170.jpg'}, {'end': 392.262, 'src': 'embed', 'start': 366.004, 'weight': 3, 'content': [{'end': 370.007, 'text': "All right, all the projects will be on the system we've been working on at that Carnegie Mellon called BustUp.", 'start': 366.004, 'duration': 4.003}, {'end': 376.972, 'text': "So this is an academic system that we've written in C++, and all the projects will be tied to this one repository.", 'start': 370.748, 'duration': 6.224}, {'end': 380.495, 'text': 'So this is why we encourage you to get started with project zero as soon as possible.', 'start': 377.313, 'duration': 3.182}, {'end': 385.299, 'text': 'To set up your dev environment, make sure you understand C++ enough in order to get through the class.', 'start': 381.616, 'duration': 3.683}, {'end': 392.262, 'text': 'Because the projects are going to be cumulative, meaning the second project will be built on what you built in the first one,', 'start': 386.059, 'duration': 6.203}], 'summary': 'Projects tied to bustup system in c++, start with project zero to understand c++ for cumulative projects.', 'duration': 26.258, 'max_score': 366.004, 'thumbnail': 'https://coursnap.oss-ap-southeast-1.aliyuncs.com/video-capture/uikbtpVZS2s/pics/uikbtpVZS2s366004.jpg'}], 'start': 86.709, 'title': 'Database lecture logistics and management systems class', 'summary': 'Covers the logistics of a database lecture sponsored by snowflake, course logistics, waitlist issues, and lecture rules, with a focus on the sponsorship and the extensive waitlist. it also discusses the importance of the database management systems class, internal system building, project guidelines, and submission requirements.', 'chapters': [{'end': 327.17, 'start': 86.709, 'title': 'Database lecture logistics', 'summary': 'Covers the logistics of a database lecture, including the sponsorship by snowflake, course logistics, waitlist issues, and lecture rules, with a focus on the sponsorship by snowflake and the extensive waitlist of 450 students.', 'duration': 240.461, 'highlights': ['Snowflake is sponsoring the class, paying for extra TAs and course development throughout the entire semester, with internships available for senior students and a guest lecture at the end of the semester.', 'The waitlist for the class is massive, reaching 450 students, making it unlikely for unenrolled students to get in, with SCS admins taking over the waitlist and enrolling new spots as they become available.', 'The instructor emphasizes his focus on databases, stating that it is the most important thing in his entire life and that he is pathologically focused on databases, with a willingness to answer any questions related to databases.', "The lecture rules include the instructor's tendency to speak fast, encouraging students to interrupt and ask questions for clarification as they go along, prohibiting questions about blockchain and discouraging post-lecture questions about specific slides."]}, {'end': 497.524, 'start': 327.17, 'title': 'Database management systems class', 'summary': 'Covers the importance of the database management systems class, the focus on building the system internally, and the guidelines for projects and submissions, including late days and platforms to be used.', 'duration': 170.354, 'highlights': ['The class is entirely about the design and implementation of database management systems, which is considered the most important class of software today. Emphasizes the significance of the class and its focus on database management systems.', 'All the projects will be on the system called BustUp, written in C++, with cumulative projects and a total of four late days allowed throughout the semester. Details the focus on projects related to BustUp written in C++ and the allowance of four late days for projects.', 'The course website, Piazza for discussions and announcements, and Gradescope for homework and projects submissions will be used, with final grades posted on Canvas. Specifies the platforms to be used for course-related activities and submissions.']}], 'duration': 410.815, 'thumbnail': 'https://coursnap.oss-ap-southeast-1.aliyuncs.com/video-capture/uikbtpVZS2s/pics/uikbtpVZS2s86709.jpg', 'highlights': ['Snowflake sponsors the class, paying for extra TAs and course development, with internships available for senior students.', 'The waitlist for the class reaches 450 students, making it unlikely for unenrolled students to get in.', 'The class focuses on the design and implementation of database management systems, considered the most important class of software today.', 'All projects will be on the system called BustUp, written in C++, with a total of four late days allowed throughout the semester.', 'The instructor emphasizes his focus on databases, stating that it is the most important thing in his entire life.']}, {'end': 1058.986, 'segs': [{'end': 556.484, 'src': 'embed', 'start': 518.038, 'weight': 0, 'content': [{'end': 523.299, 'text': 'You can discuss the code with each other, discuss high-level ideas, but you should not be sharing code with each other.', 'start': 518.038, 'duration': 5.261}, {'end': 526.483, 'text': 'Gradescope has now built-in plagiarism detector.', 'start': 524.1, 'duration': 2.383}, {'end': 527.143, 'text': 'We will use it.', 'start': 526.583, 'duration': 0.56}, {'end': 533.309, 'text': "Furthermore, because all the projects will be public, there's people, random people on the internet that also implement these things on GitHub.", 'start': 527.924, 'duration': 5.385}, {'end': 537.173, 'text': 'So all we do is do a keyword search to find 445 or bus stop.', 'start': 533.809, 'duration': 3.364}, {'end': 543.399, 'text': "We download all that, make a fake student, put that in Gradescope, and then we see whether you're copying stuff from out on the internet.", 'start': 537.513, 'duration': 5.886}, {'end': 545.4, 'text': "So please don't copy anything.", 'start': 544.079, 'duration': 1.321}, {'end': 547.761, 'text': "Please don't copy any source code.", 'start': 546.7, 'duration': 1.061}, {'end': 548.961, 'text': "Please don't copy from each other.", 'start': 547.961, 'duration': 1}, {'end': 554.283, 'text': "If you have any questions like, hey, there's this clock replacement algorithm I saw in Boost or STL.", 'start': 548.981, 'duration': 5.302}, {'end': 556.484, 'text': 'Can I use that as inspiration for my work?', 'start': 554.704, 'duration': 1.78}], 'summary': 'Gradescope has a built-in plagiarism detector and will check for copied code from the internet and other students.', 'duration': 38.446, 'max_score': 518.038, 'thumbnail': 'https://coursnap.oss-ap-southeast-1.aliyuncs.com/video-capture/uikbtpVZS2s/pics/uikbtpVZS2s518038.jpg'}, {'end': 754.934, 'src': 'embed', 'start': 727.738, 'weight': 2, 'content': [{'end': 731, 'text': "But when you register classes, I'm pretty sure it goes through Oracle.", 'start': 727.738, 'duration': 3.262}, {'end': 736.784, 'text': "And so databases are going to be the core component that you're going to counter throughout your entire career.", 'start': 731.741, 'duration': 5.043}, {'end': 741.626, 'text': "Whether or not you're staying in computer science, whether or not you're actually a developer, no matter where you go in the world.", 'start': 737.204, 'duration': 4.422}, {'end': 743.868, 'text': "at the end of the day there's going to be some kind of database.", 'start': 741.626, 'duration': 2.242}, {'end': 749.591, 'text': "It could just be an Excel spreadsheet, or it could be something that's multiple petabytes and really, really big.", 'start': 744.228, 'duration': 5.363}, {'end': 754.934, 'text': "But this is going to be the most important thing, again, that you're not going to encounter in your career.", 'start': 750.251, 'duration': 4.683}], 'summary': 'Databases are crucial in any career, from excel to petabytes.', 'duration': 27.196, 'max_score': 727.738, 'thumbnail': 'https://coursnap.oss-ap-southeast-1.aliyuncs.com/video-capture/uikbtpVZS2s/pics/uikbtpVZS2s727738.jpg'}, {'end': 1047.598, 'src': 'embed', 'start': 1021.812, 'weight': 3, 'content': [{'end': 1026.915, 'text': 'In addition to being inefficient, parsing in your code might be extremely unsafe in the format of the data.', 'start': 1021.812, 'duration': 5.103}, {'end': 1034.481, 'text': "It also might be better if the management system already had some kind of format, so no parsing required, so you couldn't inject evil data.", 'start': 1027.236, 'duration': 7.245}, {'end': 1047.598, 'text': 'His thing is that parsing in CSV could be dangerous because someone puts in a malformed character and then somehow you can do code injection like doing something malicious in here.', 'start': 1035.169, 'duration': 12.429}], 'summary': 'Parsing csv data can be unsafe and inefficient due to the risk of code injection from malformed characters.', 'duration': 25.786, 'max_score': 1021.812, 'thumbnail': 'https://coursnap.oss-ap-southeast-1.aliyuncs.com/video-capture/uikbtpVZS2s/pics/uikbtpVZS2s1021812.jpg'}], 'start': 497.904, 'title': 'Plagiarism policy and database importance', 'summary': 'Emphasizes the strict policy against plagiarism, backed by a built-in detector and public project access. it also discusses the importance of databases in career, highlighting inefficiencies of simple database models using csv files and potential security vulnerabilities.', 'chapters': [{'end': 556.484, 'start': 497.904, 'title': 'Plagiarism policy reminder', 'summary': 'Emphasizes the policy against plagiarism, highlighting that students should not copy code from each other or the internet, as a built-in plagiarism detector and public project access will be used to detect any violations.', 'duration': 58.58, 'highlights': ['Students are reminded not to plagiarize on homework or projects, as Gradescope has a built-in plagiarism detector and all projects will be public.', 'Code sharing is not allowed, and a keyword search will be used to detect plagiarism from the internet.', 'Students are cautioned against copying code from each other or the internet, as measures will be taken to identify such violations.']}, {'end': 1058.986, 'start': 556.824, 'title': 'Importance of databases in career', 'summary': 'Emphasizes the importance of databases in career, mentioning a seminar series on database systems, and highlights the inefficiencies of a simple database model using csv files, including the linear time querying, lack of organization, inefficiency in parsing, and potential security vulnerabilities.', 'duration': 502.162, 'highlights': ['The seminar series on database systems, starting on September 12th, invites industry professionals to discuss real database systems, providing an opportunity to learn about implementing techniques and methods discussed in the class.', 'The inefficiencies of a simple database model using CSV files include linear time querying, lack of organization due to unlabeled columns, inefficiency in parsing, and potential security vulnerabilities from parsing CSV data.', 'The importance of databases in a career is emphasized, stating that databases are a core component encountered throughout various career paths and emphasizing the need to understand data system software for storing and querying data.', 'The drawbacks of the simple database model using CSV files are highlighted, including the need to parse data inefficiently in the application code, the lack of organization due to unlabeled columns, and the potential security risk from parsing CSV data.', 'The chapter introduces the significance of databases in a career, emphasizing their omnipresence across different career paths and the importance of understanding data system software for storing and querying data.']}], 'duration': 561.082, 'thumbnail': 'https://coursnap.oss-ap-southeast-1.aliyuncs.com/video-capture/uikbtpVZS2s/pics/uikbtpVZS2s497904.jpg', 'highlights': ['Gradescope has a built-in plagiarism detector and all projects will be public.', 'Students are cautioned against copying code from each other or the internet.', 'The importance of databases in a career is emphasized, stating that databases are a core component encountered throughout various career paths.', 'The inefficiencies of a simple database model using CSV files include linear time querying, lack of organization due to unlabeled columns, inefficiency in parsing, and potential security vulnerabilities from parsing CSV data.', 'The drawbacks of the simple database model using CSV files are highlighted, including the need to parse data inefficiently in the application code, the lack of organization due to unlabeled columns, and the potential security risk from parsing CSV data.']}, {'end': 1592.182, 'segs': [{'end': 1136.953, 'src': 'embed', 'start': 1105.853, 'weight': 2, 'content': [{'end': 1111.154, 'text': 'And then, more importantly, what happens in the case where I have multiple albums or sorry, multiple artists in my album?', 'start': 1105.853, 'duration': 5.301}, {'end': 1112.895, 'text': 'The way I sort of design my database right here.', 'start': 1111.174, 'duration': 1.721}, {'end': 1113.935, 'text': "I can't easily do that.", 'start': 1112.895, 'duration': 1.04}, {'end': 1118.148, 'text': 'because it assumes sort of one album has one artist.', 'start': 1114.907, 'duration': 3.241}, {'end': 1126.25, 'text': 'And then what happens now if I delete the artist, how do I make sure I also delete all the albums? These are two separate files.', 'start': 1120.088, 'duration': 6.162}, {'end': 1130.371, 'text': "The file system doesn't know anything that they're connected, how they're connected.", 'start': 1126.85, 'duration': 3.521}, {'end': 1136.953, 'text': 'So if I delete GZA, how do I make sure I delete all his albums? I have to go write application code to go do that.', 'start': 1130.731, 'duration': 6.222}], 'summary': 'Challenges in database design with multiple artists per album and deletion handling.', 'duration': 31.1, 'max_score': 1105.853, 'thumbnail': 'https://coursnap.oss-ap-southeast-1.aliyuncs.com/video-capture/uikbtpVZS2s/pics/uikbtpVZS2s1105853.jpg'}, {'end': 1176.203, 'src': 'embed', 'start': 1146.306, 'weight': 4, 'content': [{'end': 1148.628, 'text': "It's just looking line by line, trying to find what you're looking for.", 'start': 1146.306, 'duration': 2.322}, {'end': 1149.97, 'text': "And when you're done, you bounce out.", 'start': 1148.648, 'duration': 1.322}, {'end': 1154.775, 'text': 'But now what happens if I have a application that wants to use the same database?', 'start': 1151.531, 'duration': 3.244}, {'end': 1158.399, 'text': 'Right now, say this is written in Python code, but I have a new application.', 'start': 1155.536, 'duration': 2.863}, {'end': 1160.881, 'text': "I want to use the same files, but I'm going to write it in Rust.", 'start': 1158.419, 'duration': 2.462}, {'end': 1162.877, 'text': 'Now, in my Rust code,', 'start': 1161.857, 'duration': 1.02}, {'end': 1168.64, 'text': "I've got to write basically the same logic to do how to parse the file and jump to what offset to find the data that I'm looking for.", 'start': 1162.877, 'duration': 5.763}, {'end': 1169.38, 'text': 'That sucks.', 'start': 1168.94, 'duration': 0.44}, {'end': 1176.203, 'text': 'Then what if I have two threads at the same time that also want to write to the file concurrently?', 'start': 1171.221, 'duration': 4.982}], 'summary': 'Challenges in reusing database files, requiring duplicate logic and concurrent writing issues.', 'duration': 29.897, 'max_score': 1146.306, 'thumbnail': 'https://coursnap.oss-ap-southeast-1.aliyuncs.com/video-capture/uikbtpVZS2s/pics/uikbtpVZS2s1146306.jpg'}, {'end': 1206.846, 'src': 'embed', 'start': 1179.124, 'weight': 5, 'content': [{'end': 1186.387, 'text': 'but again, if I have a billion records in my file, do I want to take a lock on that entire file just to update one thing?', 'start': 1179.124, 'duration': 7.263}, {'end': 1189.168, 'text': 'It would be much more efficient if I could have more fine-grained locking.', 'start': 1186.947, 'duration': 2.221}, {'end': 1194.7, 'text': 'And the last one that nobody actually brought up is durability.', 'start': 1191.718, 'duration': 2.982}, {'end': 1200.143, 'text': "So how to make sure that the data is safe if there's a problem occurs, if there's a crash or something.", 'start': 1194.72, 'duration': 5.423}, {'end': 1206.846, 'text': "So if I'm updating a record in this file and then my program crashes, what should happen??", 'start': 1201.043, 'duration': 5.803}], 'summary': 'Efficient file updates with fine-grained locking and ensuring data durability are important for managing large records.', 'duration': 27.722, 'max_score': 1179.124, 'thumbnail': 'https://coursnap.oss-ap-southeast-1.aliyuncs.com/video-capture/uikbtpVZS2s/pics/uikbtpVZS2s1179124.jpg'}, {'end': 1318.909, 'src': 'embed', 'start': 1285.236, 'weight': 1, 'content': [{'end': 1286.296, 'text': "No one's going to care that.", 'start': 1285.236, 'duration': 1.06}, {'end': 1289.697, 'text': 'oh, if your program crashes, you come back.', 'start': 1286.296, 'duration': 3.401}, {'end': 1290.417, 'text': 'all your data is safe.', 'start': 1289.697, 'duration': 0.72}, {'end': 1297.059, 'text': "That's not a distinguishing feature to sell your product versus another product.", 'start': 1290.638, 'duration': 6.421}, {'end': 1297.739, 'text': "That's sort of assumed.", 'start': 1297.079, 'duration': 0.66}, {'end': 1298.439, 'text': "It's table stakes.", 'start': 1297.799, 'duration': 0.64}, {'end': 1299.66, 'text': "Assume that you're not going to lose data.", 'start': 1298.479, 'duration': 1.181}, {'end': 1305.941, 'text': 'So why are you going to spend time in your application reinventing the wheel to make sure your files are safe,', 'start': 1300.38, 'duration': 5.561}, {'end': 1308.222, 'text': 'when you just rely on a data management system to do it for you?', 'start': 1305.941, 'duration': 2.281}, {'end': 1312.446, 'text': 'Right, database systems are widely tested and deployed.', 'start': 1309.605, 'duration': 2.841}, {'end': 1318.909, 'text': "You know they're gonna do a much better job doing all the things that we talked about here than you.", 'start': 1312.466, 'duration': 6.443}], 'summary': "Rely on database systems for data safety; don't reinvent the wheel.", 'duration': 33.673, 'max_score': 1285.236, 'thumbnail': 'https://coursnap.oss-ap-southeast-1.aliyuncs.com/video-capture/uikbtpVZS2s/pics/uikbtpVZS2s1285236.jpg'}, {'end': 1438.15, 'src': 'heatmap', 'start': 1322.771, 'weight': 0, 'content': [{'end': 1325.773, 'text': 'So you always want to be using, almost always want to be using a database management system.', 'start': 1322.771, 'duration': 3.002}, {'end': 1327.413, 'text': "We can talk about the caveats, but I don't think you want to.", 'start': 1325.793, 'duration': 1.62}, {'end': 1331.317, 'text': 'And so a general purpose data system.', 'start': 1329.676, 'duration': 1.641}, {'end': 1338.421, 'text': "it's going to allow you to define what the database looks like, create the database, put data in it, query it, update it,", 'start': 1331.317, 'duration': 7.104}, {'end': 1345.244, 'text': 'do all the administration that you want to do programmatically according to some data model.', 'start': 1338.421, 'duration': 6.823}, {'end': 1350.707, 'text': 'And so a data model is going to be the.', 'start': 1347.005, 'duration': 3.702}, {'end': 1358.811, 'text': 'the data model is going to be a way we define a high, low abstraction for the concepts that would be storing in our database.', 'start': 1350.707, 'duration': 8.104}, {'end': 1363.303, 'text': "So relational model is the key one that we'll talk about in the next slide.", 'start': 1359.981, 'duration': 3.322}, {'end': 1367.824, 'text': "But it's going to be a way to say how you define what your data looks like, the shape of it.", 'start': 1363.323, 'duration': 4.501}, {'end': 1370.486, 'text': 'Not necessarily maybe what the attributes are.', 'start': 1368.785, 'duration': 1.701}, {'end': 1371.246, 'text': 'Is it integers??', 'start': 1370.546, 'duration': 0.7}, {'end': 1372.506, 'text': 'Is it floating point numbers?', 'start': 1371.486, 'duration': 1.02}, {'end': 1377.288, 'text': 'But really, what does the core entity in this database look like?', 'start': 1372.907, 'duration': 4.381}, {'end': 1382.951, 'text': 'And the schema is going to be the way we tell the computer, or tell the database system,', 'start': 1378.589, 'duration': 4.362}, {'end': 1385.412, 'text': 'what we want this database to look like according to this data model.', 'start': 1382.951, 'duration': 2.461}, {'end': 1389.594, 'text': 'So these are listed data models right here.', 'start': 1387.372, 'duration': 2.222}, {'end': 1393.137, 'text': 'The top one here, relational one.', 'start': 1390.955, 'duration': 2.182}, {'end': 1399.362, 'text': 'this is what most database systems when you think about pretty much all the ones that we listed here we already listed at the beginning,', 'start': 1393.137, 'duration': 6.225}, {'end': 1401.384, 'text': 'except for Neo4j and MongoDB.', 'start': 1399.362, 'duration': 2.022}, {'end': 1403.926, 'text': 'these would be relational databases, right?', 'start': 1401.384, 'duration': 2.542}, {'end': 1407.209, 'text': 'This is what this course will be about, because, again, in my opinion, this is the most important one.', 'start': 1403.946, 'duration': 3.263}, {'end': 1411.467, 'text': "There's another category of systems that use these two different data models.", 'start': 1408.404, 'duration': 3.063}, {'end': 1413.068, 'text': "You might've heard of the term NoSQL.", 'start': 1411.807, 'duration': 1.261}, {'end': 1420.595, 'text': 'Typically, when people say NoSQL, they typically mean document or object model, but it kind of loosely covers all these things.', 'start': 1414.229, 'duration': 6.366}, {'end': 1426.88, 'text': "As you can imagine, the term NoSQL is not a scientific term, so this is not like, it's a loose categorization.", 'start': 1421.075, 'duration': 5.805}, {'end': 1431.945, 'text': 'You can also have a data model that finds the database of arrays, matrices, or vectors.', 'start': 1428.422, 'duration': 3.523}, {'end': 1434.127, 'text': 'This is typically used in machine learning.', 'start': 1432.485, 'duration': 1.642}, {'end': 1438.15, 'text': "It's typically used also in like, satellite imagery or medical imagery.", 'start': 1434.147, 'duration': 4.003}], 'summary': 'Database management systems are essential, with relational model being the primary focus, alongside nosql and other specialized models.', 'duration': 115.379, 'max_score': 1322.771, 'thumbnail': 'https://coursnap.oss-ap-southeast-1.aliyuncs.com/video-capture/uikbtpVZS2s/pics/uikbtpVZS2s1322771.jpg'}, {'end': 1431.945, 'src': 'embed', 'start': 1403.946, 'weight': 6, 'content': [{'end': 1407.209, 'text': 'This is what this course will be about, because, again, in my opinion, this is the most important one.', 'start': 1403.946, 'duration': 3.263}, {'end': 1411.467, 'text': "There's another category of systems that use these two different data models.", 'start': 1408.404, 'duration': 3.063}, {'end': 1413.068, 'text': "You might've heard of the term NoSQL.", 'start': 1411.807, 'duration': 1.261}, {'end': 1420.595, 'text': 'Typically, when people say NoSQL, they typically mean document or object model, but it kind of loosely covers all these things.', 'start': 1414.229, 'duration': 6.366}, {'end': 1426.88, 'text': "As you can imagine, the term NoSQL is not a scientific term, so this is not like, it's a loose categorization.", 'start': 1421.075, 'duration': 5.805}, {'end': 1431.945, 'text': 'You can also have a data model that finds the database of arrays, matrices, or vectors.', 'start': 1428.422, 'duration': 3.523}], 'summary': 'Course focuses on nosql data models and other system categories.', 'duration': 27.999, 'max_score': 1403.946, 'thumbnail': 'https://coursnap.oss-ap-southeast-1.aliyuncs.com/video-capture/uikbtpVZS2s/pics/uikbtpVZS2s1403946.jpg'}, {'end': 1497.523, 'src': 'embed', 'start': 1467.687, 'weight': 7, 'content': [{'end': 1469.147, 'text': 'So, I mean, these things still exist.', 'start': 1467.687, 'duration': 1.46}, {'end': 1475.329, 'text': "It's just no startup is saying I want to use a hierarchical data model or I want to use IMS right?", 'start': 1469.227, 'duration': 6.102}, {'end': 1477.55, 'text': "Most of the time you'll be using a relational data model.", 'start': 1475.509, 'duration': 2.041}, {'end': 1478.85, 'text': 'All right.', 'start': 1477.57, 'duration': 1.28}, {'end': 1486.293, 'text': "so for this class we're going to focus entirely on the relational data model, but I'll briefly talk about the Docker data model,", 'start': 1478.85, 'duration': 7.443}, {'end': 1488.774, 'text': 'and the key value stuff will come up throughout the semester.', 'start': 1486.293, 'duration': 2.481}, {'end': 1497.523, 'text': 'Okay, relevant, why is that?', 'start': 1489.574, 'duration': 7.949}], 'summary': 'Relational data model is the primary focus, with brief mentions of other data models.', 'duration': 29.836, 'max_score': 1467.687, 'thumbnail': 'https://coursnap.oss-ap-southeast-1.aliyuncs.com/video-capture/uikbtpVZS2s/pics/uikbtpVZS2s1467687.jpg'}], 'start': 1060.236, 'title': 'Database design and management', 'summary': 'Covers challenges in database design like data consistency and handling multiple artists, as well as implementation issues. it also emphasizes the importance of using a database management system for high availability, consistency, and efficiency, with a focus on the relational data model and drawbacks of obsolete data models.', 'chapters': [{'end': 1218.753, 'start': 1060.236, 'title': 'Database design challenges', 'summary': 'Discusses the challenges related to database design, including ensuring data consistency, handling multiple artists for an album, implementation issues like file searching and concurrent file writing, and ensuring data durability in case of crashes.', 'duration': 158.517, 'highlights': ['Handling data consistency issues like ensuring the uniqueness of artist names, dealing with case sensitivity, and preventing unauthorized data overwriting is crucial for database integrity.', 'Addressing the challenge of managing multiple artists for an album and ensuring the cascading deletion of related records presents a significant database design issue.', 'Implementing efficient file searching and avoiding redundant logic duplication across different applications can improve development productivity and maintainability.', 'Enabling concurrent file writing with fine-grained locking mechanisms is essential for scalability and performance in database systems.', 'Ensuring data durability and defining the expected behavior in case of program crashes are vital aspects of database design to maintain data integrity and consistency.']}, {'end': 1592.182, 'start': 1220.216, 'title': 'Database management systems', 'summary': 'Discusses the importance of using a database management system for high availability, consistency, and efficiency in handling and managing data, with a focus on the relational data model and the drawbacks of obsolete data models.', 'duration': 371.966, 'highlights': ['The importance of using a database management system for high availability and consistency in handling and managing data. Using a database management system ensures that data is stored safely and correctly, avoiding the need to spend time on data management within application code.', 'The focus on the relational data model and its significance in modern database systems. The chapter emphasizes the relational data model as the most important one for the course, highlighting its widespread usage and relevance in modern applications.', 'The drawbacks of obsolete data models like hierarchical data model and IMS, and their rarity in modern use cases. Obsolete data models like hierarchical and IMS are discouraged due to their rarity and obsolescence in modern applications, with a suggestion to focus entirely on the relational data model.']}], 'duration': 531.946, 'thumbnail': 'https://coursnap.oss-ap-southeast-1.aliyuncs.com/video-capture/uikbtpVZS2s/pics/uikbtpVZS2s1060236.jpg', 'highlights': ['The importance of using a database management system for high availability and consistency in handling and managing data.', 'Ensuring data durability and defining the expected behavior in case of program crashes are vital aspects of database design to maintain data integrity and consistency.', 'Handling data consistency issues like ensuring the uniqueness of artist names, dealing with case sensitivity, and preventing unauthorized data overwriting is crucial for database integrity.', 'Addressing the challenge of managing multiple artists for an album and ensuring the cascading deletion of related records presents a significant database design issue.', 'Implementing efficient file searching and avoiding redundant logic duplication across different applications can improve development productivity and maintainability.', 'Enabling concurrent file writing with fine-grained locking mechanisms is essential for scalability and performance in database systems.', 'The focus on the relational data model and its significance in modern database systems. The chapter emphasizes the relational data model as the most important one for the course, highlighting its widespread usage and relevance in modern applications.', 'The drawbacks of obsolete data models like hierarchical data model and IMS, and their rarity in modern use cases. Obsolete data models like hierarchical and IMS are discouraged due to their rarity and obsolescence in modern applications, with a suggestion to focus entirely on the relational data model.']}, {'end': 2122.869, 'segs': [{'end': 1656.189, 'src': 'embed', 'start': 1620.23, 'weight': 3, 'content': [{'end': 1622.41, 'text': 'So you can have a relational blockchain database.', 'start': 1620.23, 'duration': 2.18}, {'end': 1623.911, 'text': 'You can have a key value store blockchain database.', 'start': 1622.43, 'duration': 1.481}, {'end': 1632.518, 'text': 'In my opinion, In my opinion, the only good use for the blockchain is Bitcoin.', 'start': 1624.751, 'duration': 7.767}, {'end': 1635.54, 'text': 'Everything else is all a scam and a waste of time.', 'start': 1633.419, 'duration': 2.121}, {'end': 1637.922, 'text': 'We can talk about this later on, but there is no.', 'start': 1635.721, 'duration': 2.201}, {'end': 1643.927, 'text': "I can't think of any reason why you would need a Byzantine fault-tolerant distributed ledger for most applications, okay?", 'start': 1637.922, 'duration': 6.005}, {'end': 1646.949, 'text': "So we'll leave it at that.", 'start': 1644.708, 'duration': 2.241}, {'end': 1647.57, 'text': 'We can cover this later.', 'start': 1646.969, 'duration': 0.601}, {'end': 1656.189, 'text': "All right, so let's go back to the 1960s and talk about some of the early databases that were out there.", 'start': 1649.745, 'duration': 6.444}], 'summary': 'Blockchain databases have limited use, bitcoin being the most valid, according to the speaker', 'duration': 35.959, 'max_score': 1620.23, 'thumbnail': 'https://coursnap.oss-ap-southeast-1.aliyuncs.com/video-capture/uikbtpVZS2s/pics/uikbtpVZS2s1620230.jpg'}, {'end': 1691.536, 'src': 'embed', 'start': 1663.754, 'weight': 4, 'content': [{'end': 1667.656, 'text': "But then people realized that they didn't want to write the applications the way I showed before,", 'start': 1663.754, 'duration': 3.902}, {'end': 1671.639, 'text': "where it's hard-coded in the application how to interpret data and files.", 'start': 1667.656, 'duration': 3.983}, {'end': 1674, 'text': 'They started building these general purpose systems.', 'start': 1672.219, 'duration': 1.781}, {'end': 1675.761, 'text': 'So the earliest one is IDS.', 'start': 1674.681, 'duration': 1.08}, {'end': 1681.555, 'text': "It was actually built, I think, by GE, or I don't know.", 'start': 1678.524, 'duration': 3.031}, {'end': 1687.855, 'text': 'An IMF was built by IBM to manage the Apollo moon mission, like to manage all the parts to build the rockets.', 'start': 1682.714, 'duration': 5.141}, {'end': 1691.536, 'text': "And these things are based on something called CODASIL, which you've never heard of it.", 'start': 1688.495, 'duration': 3.041}], 'summary': 'Early general purpose systems like ids and imf were built by ge and ibm to manage data and files, based on codasil.', 'duration': 27.782, 'max_score': 1663.754, 'thumbnail': 'https://coursnap.oss-ap-southeast-1.aliyuncs.com/video-capture/uikbtpVZS2s/pics/uikbtpVZS2s1663754.jpg'}, {'end': 1817.273, 'src': 'embed', 'start': 1792.547, 'weight': 1, 'content': [{'end': 1800.155, 'text': 'He proposed the relational model in 1969 as a mathematical abstraction to how you would represent a database and interact with the database.', 'start': 1792.547, 'duration': 7.608}, {'end': 1808.023, 'text': 'So the first paper came out in the Tech Report in 1969, but then the follow-up work.', 'start': 1801.376, 'duration': 6.647}, {'end': 1813.689, 'text': 'the one that never made sense is this one from this article here in Communications of the ECM in 1970..', 'start': 1808.023, 'duration': 5.666}, {'end': 1817.273, 'text': 'And so this paper was.', 'start': 1813.689, 'duration': 3.584}], 'summary': 'Relational model proposed in 1969 for database representation and interaction.', 'duration': 24.726, 'max_score': 1792.547, 'thumbnail': 'https://coursnap.oss-ap-southeast-1.aliyuncs.com/video-capture/uikbtpVZS2s/pics/uikbtpVZS2s1792547.jpg'}, {'end': 1881.084, 'src': 'embed', 'start': 1854.449, 'weight': 2, 'content': [{'end': 1864.234, 'text': 'so the relational model defines an abstraction layer for how we want to represent relations to avoid this maintenance overhead of the Tenkawa scene back in the day.', 'start': 1854.449, 'duration': 9.785}, {'end': 1866.796, 'text': "And there's sort of three key tenets of this.", 'start': 1865.175, 'duration': 1.621}, {'end': 1871.759, 'text': "The first is that we're gonna store the database in simple data structures, i.e. relations.", 'start': 1867.616, 'duration': 4.143}, {'end': 1873.7, 'text': "I'll explain what a relation is in a second.", 'start': 1871.939, 'duration': 1.761}, {'end': 1881.084, 'text': 'And then the next key idea is that the physical storage of the database is left up to the implementation.', 'start': 1874.28, 'duration': 6.804}], 'summary': 'Relational model simplifies database storage with relations, leaving physical storage to implementation.', 'duration': 26.635, 'max_score': 1854.449, 'thumbnail': 'https://coursnap.oss-ap-southeast-1.aliyuncs.com/video-capture/uikbtpVZS2s/pics/uikbtpVZS2s1854449.jpg'}, {'end': 2012.997, 'src': 'heatmap', 'start': 1939.526, 'weight': 0, 'content': [{'end': 1941.087, 'text': 'So this is not set in stone.', 'start': 1939.526, 'duration': 1.561}, {'end': 1943.209, 'text': 'But at a high level, these are the key things.', 'start': 1941.307, 'duration': 1.902}, {'end': 1946.251, 'text': 'So Ted Codd won the Turing Award for this in 1991.', 'start': 1943.99, 'duration': 2.261}, {'end': 1948.674, 'text': 'And he died, I think, in the early 2000s.', 'start': 1946.251, 'duration': 2.423}, {'end': 1956.858, 'text': 'The other guy that invented the CODASIL, he won the Turing Award in 72, before they knew that he was wrong.', 'start': 1951.616, 'duration': 5.242}, {'end': 1957.879, 'text': "He's dead too.", 'start': 1957.418, 'duration': 0.461}, {'end': 1961.38, 'text': 'Okay So relational models are gonna have three parts.', 'start': 1957.899, 'duration': 3.481}, {'end': 1962.701, 'text': "We're gonna have the structure.", 'start': 1961.4, 'duration': 1.301}, {'end': 1965.702, 'text': 'So this is a definition of what the database relations and their attributes look like.', 'start': 1962.721, 'duration': 2.981}, {'end': 1967.863, 'text': "We'll have the integrity constraints.", 'start': 1966.642, 'duration': 1.221}, {'end': 1971.164, 'text': 'We define what data is allowed to be stored in the database.', 'start': 1967.883, 'duration': 3.281}, {'end': 1979.868, 'text': "And then we'll have a manipulation API that allows us to read data and write data and produce, run queries and produce answers.", 'start': 1971.804, 'duration': 8.064}, {'end': 1983.157, 'text': "Let's use a really simple example.", 'start': 1982.177, 'duration': 0.98}, {'end': 1986.378, 'text': "Let's go back to our Spotify application.", 'start': 1983.177, 'duration': 3.201}, {'end': 1990.66, 'text': 'The definition of a relation is going to be.', 'start': 1989.059, 'duration': 1.601}, {'end': 1997.662, 'text': "it's an unordered set that's going to attain relationship attributes that represent entities in the real world.", 'start': 1990.66, 'duration': 7.002}, {'end': 2002.163, 'text': 'The term relation, sometimes you think it means the relation between tables.', 'start': 1998.682, 'duration': 3.481}, {'end': 2004.324, 'text': 'It really means the relation of the attributes.', 'start': 2002.663, 'duration': 1.661}, {'end': 2008.325, 'text': "Throughout the semester, I've been using the word table and relation interchangeably.", 'start': 2005.224, 'duration': 3.101}, {'end': 2012.997, 'text': "For our purposes, it doesn't actually matter.", 'start': 2011.035, 'duration': 1.962}], 'summary': 'Ted codd won the turing award in 1991. codasil inventor won in 1972. relational models consist of structure, integrity constraints, and manipulation api.', 'duration': 73.471, 'max_score': 1939.526, 'thumbnail': 'https://coursnap.oss-ap-southeast-1.aliyuncs.com/video-capture/uikbtpVZS2s/pics/uikbtpVZS2s1939526.jpg'}], 'start': 1592.282, 'title': 'Evolution of databases', 'summary': "Explores the concept of blockchain and early databases, emphasizing the limited use cases of blockchain. it also discusses the birth of the relational model as a solution to the inefficiency of existing systems and provides an overview of its key tenets. additionally, it mentions ted codd winning the turing award in 1991 for the relational model's evolution.", 'chapters': [{'end': 1699.258, 'start': 1592.282, 'title': 'Blockchain and early databases', 'summary': 'Explores the concept of blockchain as a distributed ledger and its potential applications, highlighting the limited use cases other than bitcoin. it also delves into the development of early databases in the 1960s, emphasizing the shift towards general-purpose systems.', 'duration': 106.976, 'highlights': ['Blockchain is primarily used for Bitcoin and is considered a scam and a waste of time for other applications, highlighting the limited practical use cases. (Relevance: 5)', 'The chapter discusses the development of early databases in the 1960s, emphasizing the transition from hard-coded applications to general-purpose systems like IDS and IMF. (Relevance: 4)']}, {'end': 1837.127, 'start': 1699.258, 'title': 'The birth of the relational model', 'summary': 'Discusses the birth of the relational model in 1969, proposed as a solution to the problem of tight coupling between logical database structure and physical implementation, leading to the need for repetitive code changes and the inefficiency of the existing systems.', 'duration': 137.869, 'highlights': ['The proposal of the relational model in 1969 as a solution to the problem of tight coupling between logical database structure and physical implementation, leading to repetitive code changes and inefficiency of existing systems.', 'The significant impact of the relational model proposal, addressing the need for repetitive code changes and inefficiency in database development, ultimately revolutionizing the field of database management.', 'The observation of database developers repeatedly reinventing the wheel and making the same changes over and over again, leading to the realization of a better way to manage database development.', 'The recognition of the relational model as a radical and controversial idea at the time, analogous to the revolutionary concept of compiling high-level language into machine code as opposed to human-readable assembly.']}, {'end': 2122.869, 'start': 1837.147, 'title': 'Relational model overview', 'summary': "Discusses the key tenets of the relational model, including the storage of database in simple data structures, leaving the physical storage to the implementation, and using a high-level language to interact with the database system. it also mentions the three parts of relational models: structure, integrity constraints, and manipulation api, alongside the evolution of the original relational model's constraints. ted codd won the turing award for this in 1991.", 'duration': 285.722, 'highlights': ['Ted Codd won the Turing Award for this in 1991. Ted Codd was awarded the Turing Award in 1991 for his work on the relational model, which defined an abstraction layer for representing relations and significantly influenced database systems.', 'The three key tenets of the relational model are storing the database in simple data structures, leaving the physical storage to the implementation, and using a high-level language to interact with the database system. The relational model focuses on storing databases in simple data structures, deferring physical storage decisions to the implementation, and using high-level languages to interact with the database system.', 'The three parts of relational models are structure, integrity constraints, and manipulation API. Relational models consist of three main parts: defining the database relations and attributes, specifying integrity constraints, and providing a manipulation API for reading, writing, and querying data.', "The original relational model's constraints have evolved, allowing modern systems to have arrays of integers as attributes and even support JSON values. The constraints of the original relational model have evolved, enabling modern systems to store arrays of integers as attributes and support JSON values, deviating from the original model's constraints."]}], 'duration': 530.587, 'thumbnail': 'https://coursnap.oss-ap-southeast-1.aliyuncs.com/video-capture/uikbtpVZS2s/pics/uikbtpVZS2s1592282.jpg', 'highlights': ['Ted Codd won the Turing Award in 1991 for his work on the relational model. (Relevance: 5)', 'The proposal of the relational model in 1969 addressed the inefficiency of existing systems. (Relevance: 4)', 'The relational model revolutionized database management by addressing repetitive code changes. (Relevance: 3)', 'The limited practical use cases of blockchain are primarily for Bitcoin. (Relevance: 2)', 'The development of early databases transitioned from hard-coded applications to general-purpose systems. (Relevance: 1)']}, {'end': 3114.24, 'segs': [{'end': 2152.699, 'src': 'embed', 'start': 2123.91, 'weight': 0, 'content': [{'end': 2126.791, 'text': 'So what we could do is we could introduce an artificial..', 'start': 2123.91, 'duration': 2.881}, {'end': 2129.153, 'text': "I don't think this works very well.", 'start': 2126.791, 'duration': 2.362}, {'end': 2138.747, 'text': 'We can introduce an artificial column, like an ID field, that will be some unique number, some unique UUID that we assign every single record.', 'start': 2130.28, 'duration': 8.467}, {'end': 2144.212, 'text': 'So this case here, we add this thing, and this number here just represents the ID.', 'start': 2140.749, 'duration': 3.463}, {'end': 2145.673, 'text': 'And we make that the primary key.', 'start': 2144.372, 'duration': 1.301}, {'end': 2150.837, 'text': 'And then you can see here the underline and the name of the list of columns.', 'start': 2146.314, 'duration': 4.523}, {'end': 2152.699, 'text': 'The underline represents the primary key.', 'start': 2150.978, 'duration': 1.721}], 'summary': 'Introduce artificial id field as primary key for record uniqueness.', 'duration': 28.789, 'max_score': 2123.91, 'thumbnail': 'https://coursnap.oss-ap-southeast-1.aliyuncs.com/video-capture/uikbtpVZS2s/pics/uikbtpVZS2s2123910.jpg'}, {'end': 2319.69, 'src': 'embed', 'start': 2252.561, 'weight': 1, 'content': [{'end': 2260.131, 'text': 'So to do this, I can create like a cross-reference table where now I have foreign keys from the, like that.', 'start': 2252.561, 'duration': 7.57}, {'end': 2264.618, 'text': 'So I have foreign keys from the artist ID to the artist table, and from the album ID to the album table.', 'start': 2260.151, 'duration': 4.467}, {'end': 2271.74, 'text': 'So the foreign keys are going to allow us to define different cardinality relationships between different relations, like one-to-one, one-to-many,', 'start': 2265.276, 'duration': 6.464}, {'end': 2273.201, 'text': 'many-to-many, and so forth.', 'start': 2271.74, 'duration': 1.461}, {'end': 2279.445, 'text': "And we're just using these IDs to figure out how to traverse and find the data that matches up that we want.", 'start': 2273.841, 'duration': 5.604}, {'end': 2283.468, 'text': 'Yes, in the back.', 'start': 2280.606, 'duration': 2.862}, {'end': 2304.025, 'text': "His question is, is this better than an array? So Some data systems would not let you support array integers, so there's that issue.", 'start': 2284.888, 'duration': 19.137}, {'end': 2305.405, 'text': 'Other systems.', 'start': 2304.845, 'duration': 0.56}, {'end': 2310.587, 'text': "I don't know whether you can say when you define this table.", 'start': 2305.405, 'duration': 5.182}, {'end': 2319.69, 'text': 'so if we go back here, if I define this artist attribute,', 'start': 2310.587, 'duration': 9.103}], 'summary': 'Using foreign keys to define cardinality relationships between different relations for data traversal and matching.', 'duration': 67.129, 'max_score': 2252.561, 'thumbnail': 'https://coursnap.oss-ap-southeast-1.aliyuncs.com/video-capture/uikbtpVZS2s/pics/uikbtpVZS2s2252561.jpg'}, {'end': 2380.838, 'src': 'embed', 'start': 2360.342, 'weight': 2, 'content': [{'end': 2371.431, 'text': 'So one issue with an FDD, if you want to ensure that one artist can only appear on an album exactly once, once, and only once, then the array.', 'start': 2360.342, 'duration': 11.089}, {'end': 2374.453, 'text': 'you may not be able to force that into the array.', 'start': 2371.431, 'duration': 3.022}, {'end': 2380.838, 'text': 'Whereas in this case here, if I make the primary key for this cross-selectors table the artist ID and the album ID,', 'start': 2375.073, 'duration': 5.765}], 'summary': 'Ensuring one artist appears on an album exactly once with a cross-selectors table using artist id and album id as primary keys.', 'duration': 20.496, 'max_score': 2360.342, 'thumbnail': 'https://coursnap.oss-ap-southeast-1.aliyuncs.com/video-capture/uikbtpVZS2s/pics/uikbtpVZS2s2360342.jpg'}, {'end': 2632.209, 'src': 'heatmap', 'start': 2577.456, 'weight': 0.907, 'content': [{'end': 2582.037, 'text': "So we're going to focus on the first method here through relational algebra.", 'start': 2577.456, 'duration': 4.581}, {'end': 2585.778, 'text': "And then for next class, we'll talk about the declarative approach.", 'start': 2582.497, 'duration': 3.281}, {'end': 2592.724, 'text': 'Again from the mathematical model, the relational model, the mathematical lens of the relational model,', 'start': 2587.281, 'duration': 5.443}, {'end': 2599.66, 'text': 'the procedural method we covered now This declarative approach is done through relational calculus.', 'start': 2592.724, 'duration': 6.936}, {'end': 2603.562, 'text': "I'm not going to teach that because 99% of you don't need it.", 'start': 2600.32, 'duration': 3.242}, {'end': 2609.825, 'text': "If you're actually working on the internals of a database system, even then you probably still don't need relational calculus.", 'start': 2604.743, 'duration': 5.082}, {'end': 2612.987, 'text': "You only really need it if you're working on the optimizer, which is super hard.", 'start': 2609.865, 'duration': 3.122}, {'end': 2613.687, 'text': "We'll cover that later.", 'start': 2613.007, 'duration': 0.68}, {'end': 2620.291, 'text': 'But for the second one, you just think of this as SQL, right? SQL is the decoder of language that you use to interact with the duties.', 'start': 2614.808, 'duration': 5.483}, {'end': 2623.993, 'text': "Okay? All right, so let's go through relational algebra quickly.", 'start': 2621.292, 'duration': 2.701}, {'end': 2632.209, 'text': 'And then this will end up being the building blocks for how we write our query execution engine to run queries, to run SQL statements right?', 'start': 2624.605, 'duration': 7.604}], 'summary': 'Focus on relational algebra for query execution engine, sql as decoder of language.', 'duration': 54.753, 'max_score': 2577.456, 'thumbnail': 'https://coursnap.oss-ap-southeast-1.aliyuncs.com/video-capture/uikbtpVZS2s/pics/uikbtpVZS2s2577456.jpg'}, {'end': 2723.904, 'src': 'embed', 'start': 2699.247, 'weight': 4, 'content': [{'end': 2708.951, 'text': "And we're going to find this using some first-order predicate logic to specify what conditions the tuples have to satisfy in order to be used in our output relation.", 'start': 2699.247, 'duration': 9.704}, {'end': 2712.957, 'text': 'So in the original paper, they would talk to this as the restrict operator.', 'start': 2709.775, 'duration': 3.182}, {'end': 2715.839, 'text': "But in the textbook, it's going to refer to it as select.", 'start': 2713.457, 'duration': 2.382}, {'end': 2723.904, 'text': 'And the idea here is we can have multiple predicates defined in our filtering operation to do more complex things and get the data we actually want.', 'start': 2716.639, 'duration': 7.265}], 'summary': 'Using first-order predicate logic, we can define conditions for filtering operations to retrieve desired data.', 'duration': 24.657, 'max_score': 2699.247, 'thumbnail': 'https://coursnap.oss-ap-southeast-1.aliyuncs.com/video-capture/uikbtpVZS2s/pics/uikbtpVZS2s2699247.jpg'}, {'end': 2916.14, 'src': 'embed', 'start': 2879.36, 'weight': 3, 'content': [{'end': 2882.863, 'text': 'You can make these arbitrary perplexes you want in a real system.', 'start': 2879.36, 'duration': 3.503}, {'end': 2884.745, 'text': "We'll talk about query optimizer in a second.", 'start': 2883.384, 'duration': 1.361}, {'end': 2890.83, 'text': 'And its job is to figure out how to reduce it down to the most basic form to run most efficiently.', 'start': 2884.825, 'duration': 6.005}, {'end': 2898.217, 'text': 'Yes?. Is the predicates limited by the fact that they have to be proven to be false by a single,', 'start': 2892.191, 'duration': 6.026}, {'end': 2904.95, 'text': 'or can they be intratubule relationships like AID is the largest AID?', 'start': 2899.005, 'duration': 5.945}, {'end': 2916.14, 'text': 'I thought he was asking before do the predicates here have to be In the context of the scope of a single tool in my example here?', 'start': 2904.97, 'duration': 11.17}], 'summary': 'Query optimizer reduces queries to run efficiently in a real system.', 'duration': 36.78, 'max_score': 2879.36, 'thumbnail': 'https://coursnap.oss-ap-southeast-1.aliyuncs.com/video-capture/uikbtpVZS2s/pics/uikbtpVZS2s2879360.jpg'}, {'end': 3061.673, 'src': 'embed', 'start': 3015.758, 'weight': 5, 'content': [{'end': 3021.699, 'text': "so yeah, so the statement is I said that there's procedural and then the non-procedural declarative languages,", 'start': 3015.758, 'duration': 5.941}, {'end': 3023.74, 'text': "but in my examples here I'm also showing SQL.", 'start': 3021.699, 'duration': 2.041}, {'end': 3029.801, 'text': "I'm trying to teach you guys the relational algebra, which is the procedural approach.", 'start': 3024.7, 'duration': 5.101}, {'end': 3035.863, 'text': "I'm throwing in SQL, because I assume everyone knows SQL, just for you guys to map the relational algebra to the SQL statements.", 'start': 3030.341, 'duration': 5.522}, {'end': 3037.083, 'text': "That's all I'm trying to do here, yes.", 'start': 3035.923, 'duration': 1.16}, {'end': 3038.982, 'text': 'Thank you for clarifying.', 'start': 3038.422, 'duration': 0.56}, {'end': 3043.144, 'text': "Okay, let's keep going.", 'start': 3041.263, 'duration': 1.881}, {'end': 3045.605, 'text': 'All right, so projection.', 'start': 3044.565, 'duration': 1.04}, {'end': 3052.168, 'text': "this allows us to remove certain attributes that we don't want from our relation in our output,", 'start': 3045.605, 'duration': 6.563}, {'end': 3055.73, 'text': 'and we actually can reorder them and we can actually manipulate them.', 'start': 3052.168, 'duration': 3.562}, {'end': 3061.673, 'text': 'Again, this will be in the context of the input relation looking at a single tuple at a time.', 'start': 3056.35, 'duration': 5.323}], 'summary': 'Teaching relational algebra with sql mapping, focusing on projection and manipulation.', 'duration': 45.915, 'max_score': 3015.758, 'thumbnail': 'https://coursnap.oss-ap-southeast-1.aliyuncs.com/video-capture/uikbtpVZS2s/pics/uikbtpVZS2s3015758.jpg'}], 'start': 2123.91, 'title': 'Database design and query optimization', 'summary': 'Discusses the importance of keys and relationships in database design, including the use of artificial id fields and foreign keys, and also covers query optimization and relational algebra, emphasizing the role of query optimizer and the relationship between sql and relational algebra.', 'chapters': [{'end': 2357.01, 'start': 2123.91, 'title': 'Database design: keys and relationships', 'summary': 'Discusses the importance of introducing artificial id fields as primary keys, utilizing foreign keys for defining cardinality relationships between different relations, and compares the use of arrays with separate cross-reference tables for managing many-to-many relationships in data systems.', 'duration': 233.1, 'highlights': ['Introducing artificial ID fields as primary keys is crucial for data systems, and different databases have their own methods for generating these IDs, such as sequences in the SQL standard and auto increment fields in MySQL. Different databases have different methods for generating IDs, e.g., sequences in SQL standard and auto increment fields in MySQL.', 'Utilizing foreign keys allows the definition of different cardinality relationships between different relations, such as one-to-one, one-to-many, and many-to-many, and facilitates the traversal and retrieval of related data. Foreign keys facilitate the definition of different cardinality relationships and enable the traversal and retrieval of related data.', 'The comparison of utilizing arrays and separate cross-reference tables for managing many-to-many relationships in data systems, and the consideration of limitations in some data systems regarding support for array integers and defining foreign keys. Comparison of using arrays and separate cross-reference tables for managing many-to-many relationships and consideration of limitations in some data systems.']}, {'end': 2878.78, 'start': 2360.342, 'title': 'Database schema and relational algebra', 'summary': 'Discusses database schema design, including the use of primary keys to prevent duplicate entries, and introduces the relational algebra approach to query execution, emphasizing the select and projection operators and their use in filtering and data extraction.', 'duration': 518.438, 'highlights': ['The primary key for this cross-selectors table prevents duplicate entries of artist ID and album ID, ensuring data integrity. By using the primary key for the cross-selectors table as the artist ID and album ID, the database prevents the insertion of duplicate artist ID and album ID pairs, ensuring data integrity.', 'The chapter introduces the concept of relational algebra, focusing on the select and projection operators for data filtering and extraction. Introducing the concept of relational algebra, the chapter emphasizes the select and projection operators for data filtering and extraction, providing a foundation for query execution.', 'The chapter explains the declarative and procedural methods of interacting with the database, emphasizing the use of relational algebra for the procedural method. The chapter explains the declarative and procedural methods of interacting with the database, highlighting the use of relational algebra for the procedural method of defining data manipulation strategies.']}, {'end': 3114.24, 'start': 2879.36, 'title': 'Query optimization and relational algebra', 'summary': 'Covers query optimization and relational algebra, including the role of query optimizer, the use of predicates and projections, and the relationship between sql and relational algebra.', 'duration': 234.88, 'highlights': ["The query optimizer's job is to figure out how to reduce queries to the most basic form for efficient execution. The query optimizer's role is to reduce queries to the most basic form for efficient execution.", 'Predicates can be used to establish relationships and filter results, including intratubule relationships like AID is the largest AID. Predicates can establish relationships and filter results, including intratubule relationships like AID is the largest AID.', 'Projections in relational algebra allow the removal, reordering, and manipulation of attributes in the output relation. Projections in relational algebra enable the removal, reordering, and manipulation of attributes in the output relation.', 'SQL is used to map the relational algebra to SQL statements, with the chapter aiming to teach relational algebra and its application in SQL. The chapter aims to teach relational algebra and its application in SQL by using SQL to map the relational algebra to SQL statements.']}], 'duration': 990.33, 'thumbnail': 'https://coursnap.oss-ap-southeast-1.aliyuncs.com/video-capture/uikbtpVZS2s/pics/uikbtpVZS2s2123910.jpg', 'highlights': ['Introducing artificial ID fields as primary keys is crucial for data systems, and different databases have their own methods for generating these IDs, such as sequences in the SQL standard and auto increment fields in MySQL.', 'Utilizing foreign keys allows the definition of different cardinality relationships between different relations, such as one-to-one, one-to-many, and many-to-many, and facilitates the traversal and retrieval of related data.', 'The primary key for this cross-selectors table prevents duplicate entries of artist ID and album ID, ensuring data integrity.', "The query optimizer's job is to figure out how to reduce queries to the most basic form for efficient execution.", 'The chapter introduces the concept of relational algebra, focusing on the select and projection operators for data filtering and extraction.', 'The chapter explains the declarative and procedural methods of interacting with the database, emphasizing the use of relational algebra for the procedural method.', 'Projections in relational algebra allow the removal, reordering, and manipulation of attributes in the output relation.', 'SQL is used to map the relational algebra to SQL statements, with the chapter aiming to teach relational algebra and its application in SQL.', 'Comparison of using arrays and separate cross-reference tables for managing many-to-many relationships and consideration of limitations in some data systems.']}, {'end': 3986.769, 'segs': [{'end': 3173.771, 'src': 'embed', 'start': 3147.006, 'weight': 2, 'content': [{'end': 3151.29, 'text': 'All right, so now we can start bringing in multiple relations together.', 'start': 3147.006, 'duration': 4.284}, {'end': 3157.026, 'text': "So the first one's gonna be the unit operator, and this is just gonna be the basic unit operator from set theory.", 'start': 3152.005, 'duration': 5.021}, {'end': 3162.748, 'text': "You're gonna take the two relations and you're gonna combine all the results and put them together.", 'start': 3157.046, 'duration': 5.702}, {'end': 3169.63, 'text': "Now, in the original relational model, you have to have the two relations you're trying to unit together to have the exact same attributes.", 'start': 3163.348, 'duration': 6.282}, {'end': 3173.771, 'text': 'So in this case here they both have AID and BID.', 'start': 3171.11, 'duration': 2.661}], 'summary': 'Combining multiple relations using unit operator with same attributes', 'duration': 26.765, 'max_score': 3147.006, 'thumbnail': 'https://coursnap.oss-ap-southeast-1.aliyuncs.com/video-capture/uikbtpVZS2s/pics/uikbtpVZS2s3147006.jpg'}, {'end': 3200.887, 'src': 'embed', 'start': 3179.881, 'weight': 0, 'content': [{'end': 3190.364, 'text': "Again, it's unordered, it's not guaranteed to be like that, but for simplicity, we just say it is, right? So in SQL, there's a union all operator.", 'start': 3179.881, 'duration': 10.483}, {'end': 3196.946, 'text': 'And this, again, this is the difference between in SQL, they allow duplicates, in relational algebra, they do not.', 'start': 3191.604, 'duration': 5.342}, {'end': 3200.887, 'text': 'So in SQL, if you wanna allow duplicates, you have to do union all.', 'start': 3197.446, 'duration': 3.441}], 'summary': 'Sql has a union all operator, allowing duplicates.', 'duration': 21.006, 'max_score': 3179.881, 'thumbnail': 'https://coursnap.oss-ap-southeast-1.aliyuncs.com/video-capture/uikbtpVZS2s/pics/uikbtpVZS2s3179881.jpg'}, {'end': 3411.838, 'src': 'embed', 'start': 3377.928, 'weight': 6, 'content': [{'end': 3384.053, 'text': 'if you do the intersection, will everything in the intersection appear exactly twice on the relation model, not the same?', 'start': 3377.928, 'duration': 6.125}, {'end': 3390.659, 'text': "So if everything's unique in R and everything's unique in S, there's no matches at all?", 'start': 3384.093, 'duration': 6.566}, {'end': 3392.1, 'text': 'No, no, no.', 'start': 3391.64, 'duration': 0.46}, {'end': 3394.062, 'text': "Like there's no duplicates in R or S.", 'start': 3392.12, 'duration': 1.942}, {'end': 3405.554, 'text': 'appear exactly once or exactly twice? I think relation models appear once.', 'start': 3399.91, 'duration': 5.644}, {'end': 3411.838, 'text': 'Okay, but if one of them has duplicates, who knows?', 'start': 3406.515, 'duration': 5.323}], 'summary': 'Discussion about unique and duplicate elements in relation models.', 'duration': 33.91, 'max_score': 3377.928, 'thumbnail': 'https://coursnap.oss-ap-southeast-1.aliyuncs.com/video-capture/uikbtpVZS2s/pics/uikbtpVZS2s3377928.jpg'}, {'end': 3514.676, 'src': 'embed', 'start': 3481.27, 'weight': 1, 'content': [{'end': 3489.132, 'text': 'All right, so now we can start talking about The set stuff, you can do it.', 'start': 3481.27, 'duration': 7.862}, {'end': 3491.534, 'text': "It's not that common in applications.", 'start': 3489.592, 'duration': 1.942}, {'end': 3496.497, 'text': 'But now we start doing joins and those are very, very common.', 'start': 3492.214, 'duration': 4.283}, {'end': 3499.9, 'text': 'So before we get to joins, we have to talk about the product operator.', 'start': 3497.638, 'duration': 2.262}, {'end': 3503.112, 'text': 'So the product operator, also called the Cartesian product,', 'start': 3500.731, 'duration': 2.381}, {'end': 3514.676, 'text': 'is basically going to generate a new output relation that has all possible combinations of tuples on the first relation and all possible tuples on the second relation.', 'start': 3503.112, 'duration': 11.564}], 'summary': 'Introduction to the product operator and its role in generating new output relations with all possible combinations of tuples from two relations.', 'duration': 33.406, 'max_score': 3481.27, 'thumbnail': 'https://coursnap.oss-ap-southeast-1.aliyuncs.com/video-capture/uikbtpVZS2s/pics/uikbtpVZS2s3481270.jpg'}, {'end': 3733.338, 'src': 'embed', 'start': 3699.669, 'weight': 5, 'content': [{'end': 3702.19, 'text': 'In SQL, you actually can specify exactly what columns you want to get out.', 'start': 3699.669, 'duration': 2.521}, {'end': 3704.131, 'text': 'So we can ignore that.', 'start': 3703.511, 'duration': 0.62}, {'end': 3708.974, 'text': "So in SQL, there's a command called natural join.", 'start': 3705.072, 'duration': 3.902}, {'end': 3714.412, 'text': "I don't advise using this because this is going to do what I said, where they try to look to see.", 'start': 3710.09, 'duration': 4.322}, {'end': 3718.493, 'text': 'find me all the columns that have the exact same name and then do the join based on that.', 'start': 3714.412, 'duration': 4.081}, {'end': 3724.755, 'text': "It's a bad idea because now if you have, the schemas don't match anymore, it doesn't work.", 'start': 3719.253, 'duration': 5.502}, {'end': 3733.338, 'text': 'You can also use the using clause where you just say, try to match the two tables to do a join based on these individual columns.', 'start': 3724.775, 'duration': 8.563}], 'summary': 'In sql, natural join can lead to issues with matching schemas, consider using specific columns for joins.', 'duration': 33.669, 'max_score': 3699.669, 'thumbnail': 'https://coursnap.oss-ap-southeast-1.aliyuncs.com/video-capture/uikbtpVZS2s/pics/uikbtpVZS2s3699669.jpg'}], 'start': 3114.26, 'title': 'Relational model, set theory, and join operators', 'summary': 'Covers set theory operations in the relational model, including union, intersection, and difference, highlighting the distinction between sql and relational algebra. it also explains the concepts of union, intersection, difference, product operator, join operator, and their practical applications in database systems.', 'chapters': [{'end': 3433.59, 'start': 3114.26, 'title': 'Relational model and set theory operations', 'summary': 'Covers set theory operations in the relational model, including union, intersection, and difference, highlighting the distinction between sql and relational algebra, and addressing the handling of duplicates in both models.', 'duration': 319.33, 'highlights': ['The chapter covers set theory operations in the relational model, including union, intersection, and difference. The chapter discusses the fundamental set theory operations such as union, intersection, and difference within the context of the relational model.', 'The distinction between SQL and relational algebra in handling duplicates is emphasized. Emphasis is placed on the difference between SQL and relational algebra regarding the treatment of duplicates, particularly in operations like union and intersection.', 'Addressing the handling of duplicates in both models is a key point of discussion. The discussion delves into the specific handling of duplicates in both SQL and relational algebra, providing clarity on how duplicates are managed within each model.']}, {'end': 3986.769, 'start': 3436.191, 'title': 'Relational algebra and join operators', 'summary': 'Explains the concepts of union, intersection, difference, product operator, join operator, and how they are used in relational algebra and sql, emphasizing their practical applications and relevance in database systems.', 'duration': 550.578, 'highlights': ['Join operator allows matching values between two relations based on the same attributes, serving as the building block for SQL joins. The join operator in relational algebra and SQL allows matching values between two relations based on the same attributes, serving as the building block for SQL joins, which are widely used in database systems.', 'Product operator, also known as the Cartesian product, generates a new output relation by combining all possible combinations of tuples from two relations, with practical applications in testing and experimental analysis. The product operator, also known as the Cartesian product, generates a new output relation by combining all possible combinations of tuples from two relations, with practical applications in testing and experimental analysis, where all possible combinations are required for analysis.', "Explanation of the cross-join operator and the natural join command in SQL, along with the recommendation to use the 'using' clause for better flexibility in specifying columns for joining. The explanation of the cross-join operator and the natural join command in SQL is accompanied by the recommendation to use the 'using' clause for better flexibility in specifying columns for joining, as it allows the selection of specific columns for joining, providing more flexibility than the natural join command."]}], 'duration': 872.509, 'thumbnail': 'https://coursnap.oss-ap-southeast-1.aliyuncs.com/video-capture/uikbtpVZS2s/pics/uikbtpVZS2s3114260.jpg', 'highlights': ['The join operator in relational algebra and SQL allows matching values between two relations based on the same attributes, serving as the building block for SQL joins.', 'The product operator, also known as the Cartesian product, generates a new output relation by combining all possible combinations of tuples from two relations, with practical applications in testing and experimental analysis.', 'The chapter covers set theory operations in the relational model, including union, intersection, and difference. The chapter discusses the fundamental set theory operations such as union, intersection, and difference within the context of the relational model.', 'Emphasis is placed on the difference between SQL and relational algebra regarding the treatment of duplicates, particularly in operations like union and intersection.', 'The discussion delves into the specific handling of duplicates in both SQL and relational algebra, providing clarity on how duplicates are managed within each model.', "The explanation of the cross-join operator and the natural join command in SQL is accompanied by the recommendation to use the 'using' clause for better flexibility in specifying columns for joining, as it allows the selection of specific columns for joining, providing more flexibility than the natural join command.", 'Addressing the handling of duplicates in both models is a key point of discussion.']}, {'end': 4773.235, 'segs': [{'end': 4060.964, 'src': 'embed', 'start': 4031.282, 'weight': 0, 'content': [{'end': 4038.612, 'text': "In SQL, the, There is a way with nested queries you could do exactly as you're proposing.", 'start': 4031.282, 'duration': 7.33}, {'end': 4047.078, 'text': "A data system that has a good optimizer could recognize oh, I know what you're trying to do and reorder it, to rewrite it,", 'start': 4040.273, 'duration': 6.805}, {'end': 4048.199, 'text': 'to put it back the way it should be.', 'start': 4047.078, 'duration': 1.121}, {'end': 4053.223, 'text': 'So you prefer to have the database optimize it? Always, yes.', 'start': 4048.6, 'duration': 4.623}, {'end': 4060.964, 'text': 'In 99% of the cases, you want the data system to reorder things before you.', 'start': 4053.543, 'duration': 7.421}], 'summary': 'In sql, nested queries can be optimized by the database system, preferred in 99% of cases.', 'duration': 29.682, 'max_score': 4031.282, 'thumbnail': 'https://coursnap.oss-ap-southeast-1.aliyuncs.com/video-capture/uikbtpVZS2s/pics/uikbtpVZS2s4031282.jpg'}, {'end': 4107.488, 'src': 'embed', 'start': 4080.998, 'weight': 1, 'content': [{'end': 4085.581, 'text': 'see what the query optimizer does with it and then you can go back and tweak it, if necessary, later on.', 'start': 4080.998, 'duration': 4.583}, {'end': 4089.024, 'text': 'And a way to tweak it could be rewriting the SQL itself.', 'start': 4086.403, 'duration': 2.621}, {'end': 4093.825, 'text': "Some systems allow you to provide hints and say, hey, you're doing these operators in the wrong order.", 'start': 4089.624, 'duration': 4.201}, {'end': 4094.585, 'text': 'Do it in this order.', 'start': 4093.885, 'duration': 0.7}, {'end': 4096.265, 'text': "Or like, you're doing it in social scan.", 'start': 4094.965, 'duration': 1.3}, {'end': 4097.166, 'text': 'Pick this index instead.', 'start': 4096.326, 'duration': 0.84}, {'end': 4100.587, 'text': "There's a bunch of ways to force the data system to do the right thing for you.", 'start': 4097.185, 'duration': 3.402}, {'end': 4102.268, 'text': "That's not in SQL standard.", 'start': 4101.147, 'duration': 1.121}, {'end': 4103.868, 'text': 'Every data system does something different.', 'start': 4102.468, 'duration': 1.4}, {'end': 4107.488, 'text': "Postgres famously doesn't support hints, although there's extensions that do this.", 'start': 4104.648, 'duration': 2.84}], 'summary': 'Data system optimization can be achieved through sql rewriting or hints, but approaches vary across systems.', 'duration': 26.49, 'max_score': 4080.998, 'thumbnail': 'https://coursnap.oss-ap-southeast-1.aliyuncs.com/video-capture/uikbtpVZS2s/pics/uikbtpVZS2s4080998.jpg'}, {'end': 4209.454, 'src': 'embed', 'start': 4169.861, 'weight': 6, 'content': [{'end': 4173.064, 'text': 'Yes, Which comes out first, relational algebra or SQL?', 'start': 4169.861, 'duration': 3.203}, {'end': 4175.747, 'text': 'This question is what comes out first, relational algebra or SQL?', 'start': 4173.725, 'duration': 2.022}, {'end': 4178.249, 'text': 'Relational algebra was defined in 1969 by Codd.', 'start': 4176.067, 'duration': 2.182}, {'end': 4180.231, 'text': "But he's a mathematician.", 'start': 4179.43, 'duration': 0.801}, {'end': 4180.971, 'text': "He doesn't actually propose.", 'start': 4180.251, 'duration': 0.72}, {'end': 4183.354, 'text': 'But the answer is relational algebra.', 'start': 4180.992, 'duration': 2.362}, {'end': 4186.598, 'text': 'But he did not propose a programming language for his original paper.', 'start': 4183.475, 'duration': 3.123}, {'end': 4193.424, 'text': 'In 1972, Codd then came out with his own programming language called alpha.', 'start': 4189.901, 'duration': 3.523}, {'end': 4194.966, 'text': 'No one ever used it.', 'start': 4194.265, 'duration': 0.701}, {'end': 4198.828, 'text': 'IBM built a query language based on a relational model called Square.', 'start': 4196.227, 'duration': 2.601}, {'end': 4201.19, 'text': "No one could use that because you couldn't type it.", 'start': 4198.848, 'duration': 2.342}, {'end': 4202.991, 'text': 'It was still kind of math.', 'start': 4201.57, 'duration': 1.421}, {'end': 4203.551, 'text': "You couldn't type.", 'start': 4203.011, 'duration': 0.54}, {'end': 4204.752, 'text': 'You had to type it vertically.', 'start': 4203.831, 'duration': 0.921}, {'end': 4206.352, 'text': 'No one types like that.', 'start': 4204.772, 'duration': 1.58}, {'end': 4209.454, 'text': 'And then they came up with SQL.', 'start': 4208.234, 'duration': 1.22}], 'summary': 'Relational algebra predates sql, defined in 1969 by codd.', 'duration': 39.593, 'max_score': 4169.861, 'thumbnail': 'https://coursnap.oss-ap-southeast-1.aliyuncs.com/video-capture/uikbtpVZS2s/pics/uikbtpVZS2s4169861.jpg'}, {'end': 4307.969, 'src': 'embed', 'start': 4275.358, 'weight': 5, 'content': [{'end': 4277.9, 'text': "And the data system can interpret this to figure out what's the best way to execute this.", 'start': 4275.358, 'duration': 2.542}, {'end': 4283.948, 'text': 'All right, so this will be the segue for what comes in the next class.', 'start': 4280.845, 'duration': 3.103}, {'end': 4288.191, 'text': 'The relational model is independent of any actually query language implementation.', 'start': 4284.608, 'duration': 3.583}, {'end': 4291.574, 'text': 'For all intents and purposes, SQL is the de facto standard.', 'start': 4288.731, 'duration': 2.843}, {'end': 4297.939, 'text': 'Every five years, every so often somebody shows up in Hacker News and says I have a better version of SQL and it never works.', 'start': 4293.035, 'duration': 4.904}, {'end': 4298.779, 'text': 'it never fails, right?', 'start': 4297.939, 'duration': 0.84}, {'end': 4301.101, 'text': 'SQL was here before you were born.', 'start': 4299.68, 'duration': 1.421}, {'end': 4302.542, 'text': 'SQL will be here when you die, okay?', 'start': 4301.101, 'duration': 1.441}, {'end': 4307.969, 'text': "Yeah, even though IBM invented it in the 1970s, it's not a dead language, right?", 'start': 4303.263, 'duration': 4.706}], 'summary': 'Sql is the de facto standard, with no successful alternatives. it has persisted since the 1970s and is still relevant today.', 'duration': 32.611, 'max_score': 4275.358, 'thumbnail': 'https://coursnap.oss-ap-southeast-1.aliyuncs.com/video-capture/uikbtpVZS2s/pics/uikbtpVZS2s4275358.jpg'}, {'end': 4347.187, 'src': 'embed', 'start': 4310.532, 'weight': 3, 'content': [{'end': 4315.898, 'text': 'As new ideas come along, like JSON comes along, and now you can do JSON and SQL.', 'start': 4310.532, 'duration': 5.366}, {'end': 4316.779, 'text': "That's the SQL standard.", 'start': 4315.938, 'duration': 0.841}, {'end': 4321.384, 'text': "So it's adapted and evolved over time, and it looks a lot different than it did back in the 1970s.", 'start': 4317.179, 'duration': 4.205}, {'end': 4328.88, 'text': "Now the challenge is going to be, you say you know SQL, but there's the SQL standard, but nobody follows it.", 'start': 4323.078, 'duration': 5.802}, {'end': 4338.324, 'text': 'I said MySQL was a big offender, but every single database system has their own proprietary extensions that deviate from the SQL standard.', 'start': 4329.581, 'duration': 8.743}, {'end': 4342.545, 'text': "Then they sit on the standard's body and they go say, hey, I have some new functions that my system has.", 'start': 4338.904, 'duration': 3.641}, {'end': 4343.906, 'text': "Let's get to the SQL standard.", 'start': 4342.565, 'duration': 1.341}, {'end': 4346.326, 'text': 'And then Oracle says, yeah, they got something different.', 'start': 4344.446, 'duration': 1.88}, {'end': 4347.187, 'text': 'It looks slightly different.', 'start': 4346.406, 'duration': 0.781}], 'summary': 'Sql has evolved, but databases have proprietary extensions deviating from the standard.', 'duration': 36.655, 'max_score': 4310.532, 'thumbnail': 'https://coursnap.oss-ap-southeast-1.aliyuncs.com/video-capture/uikbtpVZS2s/pics/uikbtpVZS2s4310532.jpg'}], 'start': 3986.769, 'title': 'Query optimization in sql and relational algebra', 'summary': 'Covers the importance of query optimization in sql, emphasizing the significance of database optimization, the flexibility to tweak queries, and the methods to force efficient query execution. it also discusses the history of relational algebra and sql, including the initial proposals by codd, the evolution of sql over time, and the challenges in adhering to the sql standard, emphasizing the significance and ubiquity of the relational model.', 'chapters': [{'end': 4167.531, 'start': 3986.769, 'title': 'Query optimization in sql', 'summary': "Discusses the importance of query optimization in sql, emphasizing the significance of database optimization over manual query writing, the flexibility to tweak queries based on the query optimizer's output, and the various methods to force the data system to execute queries efficiently.", 'duration': 180.762, 'highlights': ['The preference for database optimization over manual query writing It is recommended to have the database optimize queries in 99% of the cases, rather than specifying the order manually in SQL, as the query optimizer can reorder queries more efficiently.', "Flexibility to tweak queries based on the query optimizer's output After observing the query optimizer's behavior, it is possible to modify the SQL and provide hints to force the data system to execute the query in the desired order, allowing for better performance.", 'Explanation of query optimizer and its role in optimizing queries A good query optimizer can recognize the intent behind a query and restructure it to execute more efficiently, although this may not always be achievable in practice due to complexity.']}, {'end': 4773.235, 'start': 4169.861, 'title': 'Relational algebra and sql', 'summary': 'Discusses the history of relational algebra and sql, including the initial proposals by codd, the development of various programming languages by different individuals and companies, the evolution and adaptation of sql over time, and the challenges in adhering to the sql standard, emphasizing the significance and ubiquity of the relational model.', 'duration': 603.374, 'highlights': ["Codd's proposal of relational algebra in 1969 preceded the development of SQL, and subsequent attempts at creating programming languages for relational models were made by various individuals and companies. Relational algebra was defined by Codd in 1969, preceding the development of SQL. Different individuals and companies, such as Codd, IBM, and Professor Berkley, proposed their own programming languages for relational models.", 'The evolution and adaptation of SQL over time, including its incorporation of new technologies like JSON, underscores its continued relevance and significance. SQL has evolved over time, adapting to incorporate new technologies like JSON, which demonstrates its continued relevance and significance in modern database systems.', 'Challenges in adhering to the SQL standard are prevalent, with most database systems having proprietary extensions that deviate from the standard, leading to disagreements and complexities in the standardization process. Adhering to the SQL standard poses challenges, as most database systems have proprietary extensions that deviate from the standard, resulting in disagreements and complexities in the standardization process.', 'The relational model is emphasized as the building block for database management, and the advantages of using the relational model over the document data model are discussed. The relational model is highlighted as the fundamental building block for database management, and the advantages of using the relational model over the document data model are emphasized.']}], 'duration': 786.466, 'thumbnail': 'https://coursnap.oss-ap-southeast-1.aliyuncs.com/video-capture/uikbtpVZS2s/pics/uikbtpVZS2s3986769.jpg', 'highlights': ['Database optimization preferred over manual query writing in 99% cases', "Flexibility to tweak queries based on query optimizer's output for better performance", "Explanation of query optimizer's role in recognizing query intent and restructuring", 'Evolution and adaptation of SQL over time, incorporating new technologies like JSON', 'Challenges in adhering to SQL standard due to proprietary extensions in database systems', 'Relational model emphasized as fundamental building block for database management', "Codd's proposal of relational algebra in 1969 preceded development of SQL", 'Various individuals and companies proposed programming languages for relational models']}], 'highlights': ['Snowflake sponsors the class, paying for extra TAs and course development, with internships available for senior students. (Relevance: 10)', 'The waitlist for the class reaches 450 students, making it unlikely for unenrolled students to get in. (Relevance: 9)', 'The importance of using a database management system for high availability and consistency in handling and managing data. (Relevance: 8)', 'Gradescope has a built-in plagiarism detector and all projects will be public. (Relevance: 7)', 'The inefficiencies of a simple database model using CSV files include linear time querying, lack of organization due to unlabeled columns, inefficiency in parsing, and potential security vulnerabilities from parsing CSV data. (Relevance: 6)', 'The drawbacks of obsolete data models like hierarchical data model and IMS, and their rarity in modern use cases. Obsolete data models like hierarchical and IMS are discouraged due to their rarity and obsolescence in modern applications, with a suggestion to focus entirely on the relational data model. (Relevance: 5)', 'Ted Codd won the Turing Award in 1991 for his work on the relational model. (Relevance: 4)', 'Introducing artificial ID fields as primary keys is crucial for data systems, and different databases have their own methods for generating these IDs, such as sequences in the SQL standard and auto increment fields in MySQL. (Relevance: 3)', 'The join operator in relational algebra and SQL allows matching values between two relations based on the same attributes, serving as the building block for SQL joins. (Relevance: 2)', 'Database optimization preferred over manual query writing in 99% cases (Relevance: 1)']}