Lec 7: How to Find Number of Candidate Keys in a Relation - part 1 | DBMS Tutorials
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- čas přidán 27. 11. 2019
- In this lecture, I have discussed a Simple Trick to Find Out all Candidate Keys in a Relation.
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Answer for exercise at 18:31
Number of candidate keys = 4
Set of candidate keys = { AB, CB , AD , CD }
Prime attributes = { A, B, C, D }
Thanks a lot ma'am !! 🤩🎊
This is one of the epic channels to learn DBMS !! Hats off !! 🙌
can you explain it?
@@carishmakhan4694 r(a,b,c,d)
ab->cd , d->b,c->a (prime attribute a,b,c,d)(if prime attribute is on the left arrow side, u can replace it with a new attribute)
ck?
abcd=(abcd)
abd=(abcd)
ab=(abcd) ->ck
(c->a so cb is sk but not sure bout ck)
cb=(abcd)-> ck
(d->b so ad is sk but not sure bout ck)
ad=(abcd) -> ck
(ab->cd so cd is sk but not sure bout ck)
cd=(abcd)-> ck
@@dsadsa5447
How does ad->c?
what I know is that you can only determine c using ab by applying decomposition rule. a alone can not determine c.
@@manytuch i think, AD->B after that we can use AB->CD to get C
@@rishabhsharma3022
Sure, I figured that out after watching the next video. Thanks
These lectures have been filling in all the information that is missing in the text books. Thank you so much!
Thank you jenny for such awesome videos...The thing that separate u from rest of the teachers is that you explain every concept with an example...and I'm a person who looks to knowledge for acquiring skill and making something from that skill rather than to just pass exams ....Thank's a lot for making such informative videos
Absolutely Brilliant. There is no doubt you are the best instructor on CZcams. I have checked out quite a few videos but none have been able to explain this core concept as clearly as you have.
Thank you mam , you are such an inspiration for all of us who are preparing for GATE
If this type of teacher will be available in India then all peoples will not have to learn like copy from book or Google then paste in exam nd also never forget any topics.... 😊 Thank you ma'm...
Exactly..
After watching several videos, not getting clear such concepts, but you make it so simple to understand. thank you so much.
AM TITUS from Ghana i have been watching your videos on data structure which is really helpful to me .God bless you .Thank you.
Really Your Technique of Teaching is Awesome.Your Viodeos are Really Helpful and understandable. Thank you Mam. You Make My Understanding About Candidate Key.
i dont know why u didnt start this series three month ago, coz i really wanted it in my last semester. I m from pakistan and i always watch your videos to clear concepts because u r much better than my lecturer ...... ->Brilliant teacher
The best course for competitive examination in Brazil cannot pass a subject at its level. Congratulations.
The explanation is very clear and easy to understand. Thanks.
you are a lifesaver, thanks for making such wonderful videos,
Thanks for your technique on finding the candidate keys. It's very very reliable compared to what I was taught in class.
somebody award this playlist!
You are the teacher. I can understand very clearly of finding candidate key😻. Before I really confused of it.😭 Thank u so much my lovely teacher. ❤
maam u are great , i like ur all videos,ur lactures help me a lot. thanku a lot
Thank you very much mam, after watching so many videos, this found to be very informative
Thank You Very Much for such excellent series on DBMS course.
Thanks Mam
Thank you MA'AM for such awesome video 🙌
Thanku so much ma’am for these lectures 🙂
How we got CD as candidate key:
we are given that C-> A and D->B, now by the help of Composition rule CD -> AB, thus AB is replaced with CD.
** Composition Rule of Armstrong's Axioms.
D->B does not stands a valid FD for the given Schema. However, BD->B stands valid[by IR1 Reflexivity property]. Your opinion would be correct iff and only if we were pre-provided with the FD D->B. However, this is not the case.
Your videos helped me in cracking GATE. Thank You so much mam.
Whats is GATE?
All the lecture in English Just The word "Ayaa Button" :)
Very informational videos ever i seen :)
Amazing ma'am ☺️...i understand all the things... thank you so much ma'am ☺️🥳
Really really such a wonderful video ma'am. Thanks a lot
Super Explanation... Very Very Thankx Maam...👌👌
Answer for last question to cross check!!
got AB,CB,CD,AD.
Yes
@@dineshtelangi3233 how AD?
@@essentialsATAesthetics D is determining B.... in place of B we can use D
Your teaching method is best and easy to understand you are really a genius. ❤❤❤
Bunch of thanks for the clear explanation🧡🧡
simply amazing. better than my professor.
Thank you so much mam really superb video 💫👌
Its remember my maths teacher. U give tough portion as assignment 😁
😍 Mam, I got Ck{ AB, CD, AB, CB } as the Candidate keys
After watching this video first time,
"Kitni awesome hain yaar.. "
🥰🥰🥰🥰🥰
Bhai thodi padhai bhi kar leta
Nice video mam always give proper solutions
Lots of thanks for this awesome explanation😊
I can't explain my word.. To say thank you.. But Thank you so much mem for your efforts to the students... 🙏💝❤
your way of explanation is too good...MAM
thank you mam, clear concept :)
love u so much mam, carry on ........
Mam could you please upload some videos related with database query . It will also be really helpful.
Mam great explanation ☺️
Good one👌👌👌👌👌
U r best teacher thank u mam🙏
Nice explanation👍
Thank you very much ma'am . you are very kind . Thank you :)
Well explained.......
Thanks mam
Allah ape ko buhat kamyabi day
Thanku maam 😘
Very helpful, thank you very much
thanks for uploading candidate key .............
My question is solved after watching this video 😊
Thanks for this mam !!
Hi jenny, can you please make a short video explaining the answer of the last question for us? I just wanted to confirm the procedure. Thanks
Jenny Mam....Really u r awesome to explain complex concept in understandable way....Really thanks to u.....
Thank you ma'am 😊
Got it ma'am AB,CB,CD,AD
PA-A,B,C,D
My favourite lectures and my favourite madam 😘😘 love you mam you are so beautiful but you didn't smile please smile mam 😅😅😅😝😬 👍👍👍
Thank You Soo much mam
Normalise watching Jenny ma'am's lectures in 1.5x 😅
wtf this person is awesome thank u :)
Hi ...myself mtech graduate ,,, your classes are amazing
Are the given FDs already a canonical cover (Fc)? Is finding the canonical cover a prerequisite to finding all candidate keys? Thanks Mam Jenny. Your lectures are great!
Candidate Keys are :AB,CD,AD,CD Prime Attributes are : A,B,C,D
very helpfully video thank you mam
Hi Jenny, what if I have FD as well as MVD? Do we only use FD to find out candidate key?
You are a darling... Thank you so much!
4 candidate keys possible- AB, CB, CD, AD
I think you're wrong there.
How can you find 'AD' please explain, I didn't understand this
Prime attributes - A,B,C,D
Ck - AB,AD,CB,CD
I've came to the same solution. So, is this correct?
AB,CB,AD,BD
@@fitnessgurl1396 BD is not even a super key. 🤣🤣
how can you please explain
how bc is termed as candidate key
mine toh only three is there AB AD AC
Thank You Mam❤!
Hi mam.. as a kind request... Pls make some videos on python programming language....
😍😎 HARD WORK NEVER FAIL
Please numbered each video with1 2 and 3 in play list it will become more organise .
you have taught very well but it is very complex
Excellent mam
I got AB, AD, CB, CD as candidate keys.
I got the same.
Yeah, I got these too.
I got these same
Explanation [Kindly correct If I'm wrong] @18:24
Ans. 4 - AB, CB, CD, AD
1. [ABCD]+ = {A,B,C,D} -> Super Key. But not candidate Key
Using, C->A, D->B, We simplify 1 as [ABAB]+ which is nothing but [AB]+
Now, [AB]+ = {A,B,C,D} -> Super key.
To check if [AB] is a candidate key,
[A]+ = {A}, [B]+ = {B} which are not super keys. So, AB is a CK
Also, Prime Attributes are {A,B} which is on the RHS of C->A and D->B.
So, the next possible super keys which we have to check as candidate keys are
Replace A with C, B with D and also AB with CD . Results are CB,CD,AD
[CB]+ -> super key. [C]+ = {C,A}. [B]+ = {B} which are not super keys => CB is a candidate key.
[CD]+ -> super key. [C]+ = {C,A}. [D]+ = {D,B} which are not super keys => CD is a candidate key.
[AD]+ -> super key. [A]+ = {A}. [D]+ = {D,B} which are not super keys => AD is a candidate key.
@@bense_tony nice work
Thank a lot . 4 candidate key . ck = {AB,ADBC,CD}
Plz bro explain how
Much love from UTCN
3 candidate keys are present in my point of view
chaa
tnk u..
Very nice
Please add english subtitle so that we(people who not having a very good listening skill) can understand you completely , thanks for well explained video though.
She's trying to teach in english,not her native language.so cooperate u moron.Instead of doing sarcasm....
@@SanjeevKumar-yt7sn I don't think it is sarcasm, if you are not used to one type of accent it can be difficult to understand sometimes. Anyway, awesome lectures
Thank you
Miss please do all videos in English because as ure thinking the whole world should benefit from your videos. For example u had done diwali video in hindi. I couldn't understand dear mam
3 candidate keys AB,CD and AD all are prime attributes
BC will also be a candidate key
@@alphonseprakash7459 what BC can determine bro is it giving the whole relation then definitely it is if not it is not
BC also will give whole relation
@@viplovekadre9371 yes bro find CB closure u get CD and C->A and B->D hence CB-> CDAB which contains all keys
Mam its really very useful . But I have a one doubt there is little bit difference between ur method and my class mams method by this can I get full mark mam.😘
❤❤❤
Super
for R(A,B,C,D,E) {A,B,C,D,E} will only be a SuperKey IF the table does not have duplicate rows right?
so for such a table how do you go about determining the maximal SK ?
AV ,CB,DA,DC are the candidate keys :)
CANDIDATE KEY : AB,AD,BC,CD
PRIME ATTRIBUTE : A,B,C,D
How can AD be candidate key plz explain
@@manishpritmani same doubt
@@manishpritmani proper subset of AD are A and D ,whose closure are not superkey ,therefore it is candidate key.
❤
Mam, Please do the videos on BackTracking, GreedyAlogrithms, Dynamic Programming Hash Table.
Thanks in Advance mam.
Already uploaded on dynamic programming and hashing..u can chk out the playlists.
@@JennyslecturesCSIT OK mam tq and then plz upload backtracking and greedy algorithms mam
Thanks in advance mam
Thnx
❣️
Mam,can u pls post the solution video for the last question as I have some doubts
Yes, the last question is harder than the solved questions😂😂
@mam, i have sat the entire day for the last hw question you gave, I got only AB and CD as candidate keys, But i am not able to understand how is CB and AD superkeys?
stop reading comments and focus on study........
hello bro....ans for questions asked by her will be seen in comment section .so that many will see comment section for that purpose.
@@tejaswigopaladasu7372 ok ok...
@@harshadlokare terer jaise hi jobless hote hein
@harshad lokare Stop commenting and focus xD...
Thanks mam