UHCL 23a Graduate Database Course - Minimal Covers Example

[@barancanboral3039]

This Professor is amazing at explaining, i am shock right now how easy he explained it.

[@dieterjacobs]

You sir are a legend, you just saved my exam. This is so easy and well-explained compared to my book here. Thanks a million!

He has just saved me too LOL

[@SavageScientist]

Finally CS in English

[@Guide4Ever]

true ffs

[@SavageScientist]

Thanks to courses like this im doing my own data structures series on youtube

[@robertkrieter9065]

Literally had to sort through all the others lol just to find a normal dude teaching it

[@nguyentu3321]

@@robertkrieter9065 Same

[@Digitals]

I'm surprised my databases professor who teaches this class at the undergraduate level is touching on this kind of theory. Anywho, your videos are AMAZING and I have learned more from watching your 10 min video than sitting in a lecture for 90 min. Thank you so much for uploading this you have saved me from a bad grade.

[@kursdragon]

Thank you so much, you explained this so easily and straightforward, understood it first time through! Much more helpful than the professor I have!

[@jassemtoumi8748]

13 years later and still helpful, thanks sir

[@Thomas91K]

I was looking for explanations on how to do this all day. I have an exam tomorrow on databases and I missed this lecture, thank you so very much for going at this so slowly and calmly. I now understand and can do the practice problems myself. You're awesome!

[@wiktoria9304]

really helpful for us, student from Poland, even 13 years later, lots of love for u man

[@jonesrz]

So well explained for a complex algorithm per se. Fantastic. If you teach this to students, the algorithm will be used from the head straightaway. Don't need any reference to the actual algorithm. Excellent for uni students. Superb!!

[@glenmacdonald3477]

Thanks Gary! Clear and concise. You taught in 10min, what I struggled to comprehend after a few hours looking through my universities lecture notes and examples (specific to simplifying the LHS).

[@rumplstielz]

you helped me so much, I can not explain. It is really awesome how simple things can be explained by one who knows what he is doing and who does not want to keep his knowledge for himself, as many other teachers/profs do... THANK YOU!

[@jffryjeffries568]

taking a graduate course in DBMS this semester, book is by garcia-molina and course is taught by one of his previous phd students (not sergey brin). however, coverage on this minimal dependencies topic is minimal (ha...ha...), and after much frustration I took to youtube. this video is great! Thanks dr boetticher

[@harclevuyk]

Thnx a lot Professor . You are a great person . It was very hard for me to understand that using my professor's lessons . Blessed are those who give without remembering.

[@fatimazahraedakki4203]

thank you so much you are the only one who explained it in a easy way

[@skenderoo]

Watching this in 2023, I finally understand this topic after failing the first database exam. Thank you very much for saving me! Greetings from overseas :)

[@mattt7806]

Sir: Thank you so much for a great educational video. You explained the topic in a very easy and comprehensible language. I have watched all your videos and they are all great.

[@xRoboRedx]

Finally...a clear, easy to understand explanation. Thank you!

[@andy76667]

Amazing, well explained, not too fast, not too slow, just great.

[@d1357900]

I study at GMU ..I thought that my prof is good but after watching you....ideas are clear !!!

[@GaryBoetticher]

Hi Arijit: Thanks for watching the videos! The course syllabus contains all the videos. Google the following words: boetticher 5333 Best wishes, Dr. B.

[@lucam9806]

Thank you very much. It makes a lot of sense the way you explained it. I think i finally understand it. I only have one week left to study for my exam.

[@geogaddi84]

I love how systematic you made this. It's the hill I am going to die on on my final....

[@CustomNameHere]

That is best explanation for determining minimum covers (bias) that I have found. Thank you!!

[@kumaranthiru3505]

Thank you sir.. I've confused myself when I'm going through this concept. Your explanation is so crisp, understandable and easy. I'm clear now, in finding the minimal cover from the given set of functional dependencies. Thanks again

[@shadoninja]

You are a boss

[@chaosolid]

The explanations and tricks really made the life much easier. Thank You!

[@ItzTinonTime]

A very great video. I finally understood the method and the procedure. Thank you!

[@johnds123]

Thank you so much...I so wish you were my Database teacher right now...

[@GaryBoetticher]

@nxjohny You may eliminate either the A or the B. Given a set of FDs, there may be 2 more minimal covers.

[@cawker1984]

Great video. Thank you for explaining everything and not skipping steps. It was extremely clear :)

[@AshleyJae12]

Thank you so much, your detailed explanation really saves me lots of time struggling to understand this topic just before examinations :D

[@mindroam]

Excellent explanation. Very easy to follow. Thanks for uploading!

[@19bakke]

great, thanks Gary, you have helped me so much in this video!!!! Keep up the good work, many thanks from Ireland!!

[@AA-fe1zl]

Mate this video is so well done and concise. Thank you so much!!! Also, it's not in Hindi like the other 10 thousand videos on KZbin which helps.

[@kraller1992]

Great explanation Gary, thanks a lot!

[@teodorvb]

You just saved my live. This was the ultimate help.

[@seashock]

Thanks a lot professor! Your explanation really helped me before my Final Exam.

[@vivekpandey6688]

Thanx a lot to you sir I was struggling with this for 1 week I have semester on monday so hopefully I am clear with the topic after watching your Video.😊👍 keep making this kind of videos it helps a lot .

[@darley436]

this video is a life saver !!

[@juansemoralesmusic]

@TheNemoooz since we have C-> B (bottom line), then C closure will include the B, and therefore the A as well (in the FD we are analyzing)

[@gyeongminkim5215]

Finally i found the video that explain what the "minimum cover" is

[@LaughingBread]

For eliminating the LHS attributes, I think it's because the closure contains the RHS attribute that you can eliminate the LHS attribute. So for the BC-> D, closure on C contains D, so you can eliminate B, not because C contained B that you eliminate B.

[@asadaleem4601]

I had the same question. I think you are right.

[@felixstoger2800]

It probably won't help you anymore, but maybe it will help someone else. The thing is, that as soon as B \in C^+, then we know that by reflexivity, C, B \in C^+. Moreover, by union of FDs, we get that C -> B AND C -> C => C -> BC (this is intuitively clear, but to formalize it one can use the rule). Hence, we get C -> BC, BC -> D, i.e. C -> D by transitivity. So, the statement that B \in C^+ => can simplify BC -> D to C -> D holds :). One can even prove my induction, that for a LHS of n attributes, if one element, say "B", entails the other (n-1), then wen can get rid of these (n-1) and just keep "B".

[@sunoharachan3820]

At time 3:43, if for example the closure of B contained D, but not C then we would still get rid of C resulting in B -> D?

[@giack6235]

Hello, thank you for the very clear video. Just a question: at 9:46 you are saying that swapping steps 2 and 3 you get an incorrect answer, why? (my book instead tells it must be done first step 3 and then step 2 instead)

[@danielbetter4320]

Great explanation. Very easy to follow and understand. Thanks.

[@mbadashehady3261]

How to find if there is more than one minimal cover?

[@amirkamel8]

This is so awesome, so useful for my final exam of DB

[@SuperWacky15]

great video! The way in which you explained was too good sir! thank you :)

[@rcbevans]

For the final step, do you only look for redundant FDs with singles on the LHS? Still trying to form something containing the RHS in the closed set?

[@akshayajddn]

Hello Chintan, if you have 2 attributes on RHS for eg:- A->BC, then it would imply A->B and A->C, however if AB->C, then we cannot write A->C and B->C Hope it answers your question..:)

[@TheNemoooz]

great video, but I have one question though. In the 2nd step of removing extraneous left attributes, and we wanted to find the closure of C in the FD (BC -> A), why did we use this same functional dependency that I am trying to reduce. I am trying to reduce the BC and therefor shouldn't use it, maybe just use the C ??

[@stefano_fiore]

That's how to explain in a clear and simple way... thank you

[@chaozkreator]

Hi, does L-reduced (left reduced) mean the same as your step 2, where you remove extraneous attributes on the left hand side? My lecturer use slightly different notations and I don't really get it, and most materials I found are the same as what you used, but are different to what my lecturer uses. The definition he gave on L-reduced is that for every X->Y that belong to a set of FDs and for all X->Z, we do NOT have Z->Y.

[@GIChiyo]

Thank you so much for explaining this. It 100% makes sense now.

[@BREEZERHD123]

Not every hero wears a cape! Thank you sir!

[@HGezeery]

Easy and simple to understand. Thank you !

[@labpluto123]

You are awesome, you've made one of my hardest class relatively easier!! Allaaahh

[@nxjohny]

Just a short question: What should i do, if in the second step, when we eliminate the extraneous member of the left hand side, for example AB the left hand side, and the closure of A contain B and B closure contain A.

[@ChitrakShaw]

Thanks! Semester preps just got better!

[@AnamitraBoseIsHere]

Koto poris tui! -_-

[@ChitrakShaw]

Copy cat.

[@Josh1billion]

You explained this very, very clearly. Thank you for uploading it. :)

[@atulrana102]

thanks..got everything clearly..I needed it for my exams badly..

[@victoriac7257]

Somehow in my textbook they do not allow the same left side. So I assume we should just put C->A and C->B to C->AB?

[@Travigne]

thanks alot. Regarding to remove extraneous attributes, for example if i have F = {AE->BC, BE->C, AE->D}. Can we reduce attribute on the right hand side of BC? If yes, how do we know?

[@starizard42]

Thanks a lot Prof. Gary !!! this helped me a lot

[@rnramakr]

excellent and concise explanation. Thanks!

[@jayanth_luffy]

Thank u sooooo much sir :) I got the complete idea about how to find the minimal cover, thanks to u.....

[@JanaSuzanne]

thanks, i understood more in 5 minutes than i did 3 hours reading my textbook

[@hunt007a]

thank you proffessor...your lectures are very soothing....how can i get the entire bunch of all your database videos

[@MrLazini]

Very informative video, thanks Professor !

[@cennerz]

Thank you sir ur tutorials are superb and easy to understand

[@lucam9806]

My professor told us to summarize the FDs which have the same left-hand side. So that C-->A and C--> B would become C-->AB at the end. Would this also be correct?

[@d41d8cd]

What if I have, say, ABC -> D? I should test every possible subset of ABC (A, B, C, AB, AC, BC), right?

[@YKLUO]

this one ist what i am looking for! thx for sharing this!

[@kksandyrox]

what if there are 3 elements on the right hand side? how to decompose and move forward? ex: D-->AEH?

[@chintandesai9459]

thank you sir for this great and easy tutorial but i have question what if we have 2 elements on right hand side ?

[@atrirules]

Are canonical covers and minimal covers the same?

[@Emilia-jh2hi]

This video is so good ! Thank you !

[@chinamd1971]

I like the video thanks for sharing. I am having a bit of a struggle with my attribute set ABCDEFGH. Do all attributes have to be present in a minimal cover?

[@talibshabbir7839]

Hello Sir, Whats is minimal SET of FD and what is the difference between minimal set of FD and minimal cover of FD.. I have understood minimal cover very well, Thank you for that.. And can you please tell me the trick to find primary key from the above example or any example you want..

[@BreezyInfernoNinja]

is minimal cover the same as minimal basis?

[@talibshabbir7839]

Hello Sir, What is minimal SET of FD and whats the difference between minimal covers and minimal set of FD.. I have understood minimal covers very well..Thankyou for that.. And can you tell me the trick to find primary key from the above FD

[@XGamerJan]

Excellent explanation!

[@orhancanceylan]

Thank you very much for that video ! But I have a question, after doing all of these steps, will the minimal cover also be a boyce codd normal form ? Or is each left side of the FDs a key ?

[@yashsoni6366]

owesome explinaton,,,,finally i understand whats canonical cover just bcz of this tutuorial

[@xzillione]

wow this is awesome.. u just helped me past my final!!

[@hiddeninplainvw6]

This video great.. explains a complicated subject very well

[@ON-zd3vf]

Can you combine C->A and E->A so that it reads CE->A ?

[@nitingovil391]

Consider a given relation R=(P,Q,R,S) with following set of FDs: PQ→R PS→Q QS→P PR→Q S→R Find the minimal set of FDs from the above set. Please help

[@selineryilmaz1961]

How to eliminate BC-->D??? (C+={CAD}. I dont understand where is it come B there?D is not go anywhere ???

[@howlade3]

Amazing Tutorial for DB, its really helpful!!

[@leutekon]

one question? is minimal cover same as the so called ''canonical cover?''

[@GuitarwolfZero]

Much easier to understand compared to those confusing algorithms in textbooks.

[@TheCarlosis]

is minimal the same as Canonical cover:

[@moray8882]

Thank you very much! Love from Austria

[@MaxDiscere]

Thanks Mister Bötticher, very helpful

[@AshwathMenon]

Hello Gary, Thanks for posting such an informative session on minimal cover. I have a query regarding this, consider if I have a relation 𝑅(𝐴,𝐵,𝐶,𝐷,𝐸,𝐾,𝐺,𝐻,𝐼,𝐽) and its FD set 𝐹={𝐴→𝐻,𝐺→𝐴,𝐸→𝐷,𝐷→𝐴𝐺,𝐸→𝐻𝐼,𝐴𝐵→𝐶𝐷,𝐴𝐵𝐶→𝐸𝐾,𝐴𝐶𝐷→𝐾𝐺}. So as per your first step, i have reduced the terms on the right side and now will doing the step 2, i have a relation AB-> C and AB->D So from here A* = {A,H} and B* = {B}. In this case how do I proceed further.

[@piacare]

When computing C+ in the first example, BC->A was used to get A in the closure. But then you remove B from BC->A... wouldn't you then not be able to get A in the closure anymore? Seems like circular reasoning...

[@uberripebanana]

***** BC->A look at closure of C without that relation: C+ = {C,B}. You see that C->B If B played an important role in BC->A, it wouldn't make sense that C->B. So we can cut the B and get C->A. Then A can be added to C+={C,B,A} using C->A.

[@Turretism]

Really well explained, thank you very much.

[@kpongsukjai]

Thank you for the great explanation.!!!

[@meshaelshahid7082]

Excellent explanation