caubert / CSCI_3410 (public) (License: CC BY 4.0) (since 2018-05-16) (hash sha1)
Material for Database Class.
Clone URLs: https://rocketgit.com/user/caubert/CSCI_3410 ssh://rocketgit@ssh.rocketgit.com/user/caubert/CSCI_3410 git://git.rocketgit.com/user/caubert/CSCI_3410
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List of commits:
Subject Hash Author Date (UTC)
Fixing NF part. 111dff5a3e9d04c66644b07bf1b57f042397acdc caubert 2021-10-15 17:34:08
Added exam 1 d0dd69017e6ec6a7c476fef569e4e6480230e099 caubert 2021-09-20 13:53:49
Fixed vote rel. model. 579bcb33b94039787bdb5f477394b428f0249666 caubert 2021-09-17 19:00:31
Added some precision following course. b5b1e27b4190ddc10df2b0383bed289be8d7a556 caubert 2021-09-01 18:34:26
Added example about self-referencing tuple. 0392e724d84f2a9264fec4be188fa74ef795266a caubert 2021-08-30 18:56:34
Clarified what a mini-world is. 7bc9938cbdcc8be11cd61c74899b330d626ec2b5 caubert 2021-08-25 16:23:12
Added emoji support and cleaned. f7b577db596410737f72c93fbcab615b53226ac5 aubert@math.cnrs.fr 2021-08-17 13:35:36
Finished final from previous semester. 7622ebd223bbbabaed014a175a0be5da7aff5d6f caubert 2021-08-13 17:05:28
Added final for Spring 2021. 6a4a0d94151df7ab940c814637be8ee5136de850 caubert 2021-08-13 16:55:09
Typo f1acfa7bcd31233571e74e176ee2a38880c08d72 caubert 2021-05-07 02:55:17
Added second problem of final. 38c448de2d0e38bf50efcf1b1da3e0a45def1707 caubert 2021-05-07 01:42:05
Added first exercise of final. df858593f1d47ff3442bcb6216b90605d81e0e1c caubert 2021-05-06 22:26:09
Fixed mongo db and added quiz 4$ 7f0f4b98f4b293927185ed3cb080554eb3af867c caubert 2021-04-23 19:15:53
Finishing with Exam 2 4e0eb343744b5f39ac32145ca7dc61a26b3f48ee caubert 2021-04-09 20:33:48
Added problem and solution of second exam 2b344a25e84c7ebc827c1503151981380ec08f31 caubert 2021-04-07 18:08:08
Worked on exam 2 649fce8b5cbc3f5a98ae905ae8cc56d8baa5df99 caubert 2021-04-06 19:18:54
Clarification on sql injection. f9450ef20ef15cc048c1c2775cbf5e29c4be7255 caubert 2021-03-31 14:56:56
Added an example of batch processing of prepared statement. f83adc39b5066412fa78fdc0aeccb51ccdba908a caubert 2021-03-31 13:39:52
Added an example of batch processing of prepared statement. c206f2899162396a7f391728db8be23031253454 caubert 2021-03-31 13:38:48
Fixed pb (CONSULTATION relation: justification, primary key and normal form) 14aef6161421064f879c5fe803abb4836eebba0a caubert 2021-03-25 20:58:59
Commit 111dff5a3e9d04c66644b07bf1b57f042397acdc - Fixing NF part.
Author: caubert
Author date (UTC): 2021-10-15 17:34
Committer name: caubert
Committer date (UTC): 2021-10-15 17:34
Parent(s): d0dd69017e6ec6a7c476fef569e4e6480230e099
Signer:
Signing key: 9406C0CE110CFCB0
Signing status: E
Tree: 03319c2ab24fc485560d3834c4bd3efe06ecde00
File Lines added Lines deleted
notes/example.md 4 1
notes/fig/fd/course_norm_01.tex 1 1
notes/fig/fd/example_2NF_02.tex 2 2
notes/fig/fd/example_2NF_03.tex 1 1
notes/lectures_notes.md 9 9
File notes/example.md changed (mode: 100644) (index 9289c51..effe12d)
... ... This is an example that shows how to include a UML activity diagram:
81 81 # Code Examples # Code Examples
82 82
83 83 By defaut, the code is colored as `SQL` code, due to the By defaut, the code is colored as `SQL` code, due to the
84 ```--lua-filter filters/default-code-class.lua -M default-code-class=sqlmysql```
84
85 ```
86 --lua-filter filters/default-code-class.lua -M default-code-class=sqlmysql
87 ```
85 88 option given to pandoc. option given to pandoc.
86 89 You can refer to <https://github.com/jgm/pandoc/issues/2104> for a discussion on that topic. You can refer to <https://github.com/jgm/pandoc/issues/2104> for a discussion on that topic.
87 90
File notes/fig/fd/course_norm_01.tex changed (mode: 100644) (index 9e63b26..5a8b407)
10 10 \depedge[lvl=1]{3}{5}{} \depedge[lvl=1]{3}{5}{}
11 11 \depedge[lvl=1]{2}{4}{} \depedge[lvl=1]{2}{4}{}
12 12 \depedge[lvl=1]{8}{9}{} \depedge[lvl=1]{8}{9}{}
13 \depedge[lvl=1, FK, edge above]{8}{3}{}
13 \depedge[lvl=1, FK, edge above]{3}{8}{}
14 14 \end{dependency} \end{dependency}
15 15
16 16 \end{document} \end{document}
File notes/fig/fd/example_2NF_02.tex changed (mode: 100644) (index c364a66..5478144)
9 9 \depedge[lvl=1]{3}{4}{} \depedge[lvl=1]{3}{4}{}
10 10 \depedge[lvl=1]{7}{8}{} \depedge[lvl=1]{7}{8}{}
11 11 \depedge[lvl=1]{11}{12}{} \depedge[lvl=1]{11}{12}{}
12 \depedge[lvl=1, FK, edge above]{7}{3}{}
13 \depedge[lvl=1, FK, edge above]{11}{3}{}
12 \depedge[lvl=1, FK, edge above]{3}{7}{}
13 \depedge[lvl=1, FK, edge above]{3}{11}{}
14 14 \end{dependency} \end{dependency}
15 15
16 16 \end{document} \end{document}
File notes/fig/fd/example_2NF_03.tex changed (mode: 100644) (index be82209..f274450)
9 9 \depedge[lvl=1]{3}{4}{} \depedge[lvl=1]{3}{4}{}
10 10 \depedge[lvl=1]{7}{8}{} \depedge[lvl=1]{7}{8}{}
11 11 \depedge[lvl=1]{7}{9}{} \depedge[lvl=1]{7}{9}{}
12 \depedge[lvl=1, FK, edge above]{7}{3}{}
12 \depedge[lvl=1, FK, edge above]{3}{7}{}
13 13 % \depedge[lvl=1, FK, edge above]{11}{3}{} % \depedge[lvl=1, FK, edge above]{11}{3}{}
14 14 \end{dependency} \end{dependency}
15 15
File notes/lectures_notes.md changed (mode: 100644) (index ea61950..ffc95ad)
... ... A FD : $X → Y$ is a **transivive dependency** if there exist a set of attribut
6394 6394
6395 6395 ### Normal Forms and Keys ### Normal Forms and Keys
6396 6396
6397 First, Second, Third, Fourth, Fifth normal form ("X"NF).
6398 Stronger than the Third, there is the Boyce-Codd NF (BCNF)
6399
6400 If you satisfy $N$, you satisfy $N-1$, $N-2$, etc.
6397 There exists multiple normal forms: First, Second, Third, Fourth, Fifth normal form ("X"NF), …
6398 Stronger than the Third, there is the Boyce-Codd NF (BCNF), but we will focus on the first three, that are "cumulative": to you satisfy $N$, a relation have to satisfy $N-1$, $N-2$, etc.
6401 6399 The *normal form* of a relation is the highest normal form condition that it meets. The *normal form* of a relation is the highest normal form condition that it meets.
6402 6400
6403 6401 #### Fist Normal Form #### Fist Normal Form
 
... ... Hence, we will always assume that a primary key is given, and it will be underli
6412 6410
6413 6411 ##### Normalization ##### Normalization
6414 6412
6415 **To be written**
6413 This essentially consists in
6414 - Picking a primary key,
6415 - Making the complex and multi-valued attributes atomic, following what was done when mapping entity-relationship models to relational models: by either "flattening" the complex attribute (i.e., picking the attributes composing it) or by creating a relation that will allow to store multiple values and linking it to the original relation.
6416 6416
6417 6417 #### Second Normal Form #### Second Normal Form
6418 6418
 
... ... For each attribute $A$ of the relation whose primary key is $A_1, …, A_n$:
6431 6431 - Yes, it depends only of $\{A'_1, …, A'_k\}$ → Do the following: - Yes, it depends only of $\{A'_1, …, A'_k\}$ → Do the following:
6432 6432 - Create a new relation with $A$ and $\{A'_1, …, A'_k\}$, make $\{A'_1, …, A'_k\}$ the primary key, and "import" all the functional dependencies, - Create a new relation with $A$ and $\{A'_1, …, A'_k\}$, make $\{A'_1, …, A'_k\}$ the primary key, and "import" all the functional dependencies,
6433 6433 - Remove $A$ from the original relation, and all the functional dependencies that implied it, - Remove $A$ from the original relation, and all the functional dependencies that implied it,
6434 - Add a foreign key from $\{A'_1, …, A'_k\}$ to their original counterparts in the original relation.
6434 - Add a foreign key to $\{A'_1, …, A'_k\}$ from their original counterparts in the original relation.
6435 6435
6436 6436 ![](fig/fd/course) ![](fig/fd/course)
6437 6437
 
... ... For instance, considering
6445 6445
6446 6446 ![](fig/fd/example_2NF_01) ![](fig/fd/example_2NF_01)
6447 6447
6448 applying the algorithm would give
6448 applying the algorithm would give (the incorrect, since a foreign key can not refer two attributes in two different tables)
6449 6449
6450 6450 ![](fig/fd/example_2NF_02) ![](fig/fd/example_2NF_02)
6451 6451
 
... ... whereas a more subtle algorithm would give
6453 6453
6454 6454 ![](fig/fd/example_2NF_03) ![](fig/fd/example_2NF_03)
6455 6455
6456 Note that in both cases, all the relations are in Second Normal Form, though.
6456 Note that in both cases, all the relations are in Second Normal Form, though (and valid if we ignore the foreign key issue discussed above).
6457 6457
6458 6458 Note also that, sometimes, removing the "original" relation may be preferable: cf. an example in [%D %n (%T)](#problem:coffeeNF). Note also that, sometimes, removing the "original" relation may be preferable: cf. an example in [%D %n (%T)](#problem:coffeeNF).
6459 6459
6460 Note also that if our primary key is a singleton, then there is nothing to do, we are in 2NF as soon as we are in 1NF.
6460 Note also that if our primary key is a singleton (a set with only one element), then there is nothing to do, we are in 2NF as soon as we are in 1NF: every functional dependency from a single element is always full!
6461 6461
6462 6462 #### Third Normal Form #### Third Normal Form
6463 6463
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