Lec 19: Practice Problem on Lossless Join Decomposition | DBMS Tutorials

[@chandrashekarr1977]

Kudos... For the first time am seeing a lecture in English from North India.. thank you

[@bense_tony]

Just in case if you are confused @20:27. Simple trick said by mam earlier is... C+ = {A,B,C} It has all the attributes of R1(A,B,C) which means, C is a super key. Also, C is a single attribute. So, it is a candidate key, since no proper subsets of C[which are just empty sets] is a super key.

[@gulcesafiye9579]

You are litterally perfect . I have been struggling to understand this topic ,I have found this playlist and now everything is crystal clear . You are amazing

[@ebrimajobe6535]

you deserve some credit ma'am. Everything i learned from you is more than explicit. Thanks!!

[@rithviksenthil7152]

At 14:47 we cannot say AB is a candidate key. A candidate key is a mimimal superkey. So A would be the candidate key. AB is a superkey.

[@deepakdobhal4388]

The common attribute of both the sub relations must be a super key of either R1 or R2 or both. if someone confuses in SK or CK. Every CK is super key but not all SK is CK. Mam is saying all time CK so plz consider it as SK. bcz in 4th sub-relation AB is not CK. it's SK.

[@souravsengupta627]

Plz make a video related to foreign key and primary key and the way of joining the tables.... ASAP.

[@impatientoptimist5632]

Toppee because of your bloopers 😆😆bcoz i started following you after your blooper😆😆

[@nickmorgan2822]

Beautifully explained. thank you. also I love your coat😉

[@ganeshrams4246]

Thank you so much mam,all your videos are very clear and it helps me to prepare gate/net exam very easily, u have saved my time .thanks a lot

[@p.bayapureddy6117]

I am in love with your eyebrows

[@nishantraj3869]

Love lapati chhod do bro... Sikhlo kuchh , Your perfection will make you glow . Jarurat nhi padegi tumko kisi ko love this that ya wahh krne ki.... After all bro.. pasand to hmm v krte but kya kare she is my online teacher .

[@snehasaha2310]

you're savior 😇

[@Russia_wala_Putin]

Bhai main commerce se hu pr pdh k a6a lg rha hai 😍😍😍

[@anshuraj6455]

You are great mam... 📲📲📲📲

[@elyasaf755]

Very clear. Thank you!

[@Attitudeandsigma]

Mam please continue your Valuable videos for gate please mam

[@M_Rimi]

Thank you mam 😊 you are great 😘

[@pavankumar8673]

The definition shouldn't be for candidate key because at 15:27 we have abc and you termed ab as candidate key ,but since a is a superkey, this is not valid. Instead you should change the terms you use, mam

[@pavankumar8673]

Instead of candiate key, just term that common attribute must be superkey

[@rukaiyadalroti2886]

At 13.55 your are deriving b can derive CDE in which due to at value of b at 1 having different value it can't be derive but if we take 3 in common from (6,3,6)than it can became similar soo can we do it that after removing common divider make it similar or not....?

[@RishiRaj-zs4fh]

Why aren't you making more videos on other computer science topics as well or on DBMS. At least with your help, we can really increase our knowledge in DBMS.

[@Mayurishihz11]

Thanks for this video

[@FINANCIALYOGI]

Is it ok to discard a tuple from a relation formed after decomposing R? Won't it be loss of record. Kindly explain. Thanks.

[@pranilthakare]

interesting ma'am thank u

[@anishjoshi1999]

love from nepal

[@velagabhavyasri6720]

Pls do on 4nf, 5nf and Multivalued dependency mam

[@rajsarkar]

Why should we remove the second 1 3? . I done it with it and its forming Lossy join where as while i removed it it created lossless join.

[@SureshBabu-og4ys]

Consider the relation R(P, Q, S, T, X, Y, Z, W) with the following functional dependencies. PQ → X; P → YX; Q → Y; Y → ZW Consider the decomposition of the relation R into the constituent relations according to the following two decomposition schemes. D1 : R = [(P, Q, S, T); (P, T, X); (Q, Y); (Y, Z, W)] D2 : R = [(P, Q, S); (T, X); (Q, Y); (Y, Z, W)] Which one of the following options is correct?

[@yaswanthb9733]

@@SureshBabu-og4ys first one

[@kailashuv3028]

Didi ,can you please make a video about "lpp simplex" method to attain optimal solution....

[@shyamprakashm6325]

Yes dude each book and videos teach different manner and different solution has arrived😥😥😣😣😣

[@Aakash-p7x]

Take Note : If Common attribute is CK of any one then it's lossless❤

[@ahmadabbas1836]

I love your eyes looking like carrer post graduate institute of medical science

[@SaurabhjiEngineer]

How AB can be ck,since A subdomain is a superkey? In 4th number ,16 min

[@gurjotsingh5924]

please add videos on network models and constraints in dbms.

[@axelbelkacemi7697]

I think there's a contradiction in the 4th decomposition : you said if A has distinct values then definitely AB determines C, so AB is CK . but A has different values means that it's SK (subset of AB is SK) what means that AB is not CK ... I'm confused , does it mean that its not lossless decomposition?

[@kirajan7333]

Mam was not talking about CK or SK, she was saying that if A has distinct values then AB combination also distinct values and there is no common rows of AB in table because A is like primary key with no duplicate values so AB will derive C

[@deepakdobhal4388]

AB is SK so still its lossless decomposition. The common attribute must be a SK.

[@arslanamjad2385]

Make some lectures in urdu mam Some people have poor english like me Reply please about my opinion mam Arslan from pakistan

[@nishantraj3869]

Hindi sikhna hai to bolo ... Hmm bataenge

[@MegaNivetha]

Madam how to find functional dependency then describe about how to find normalisation.madam please take some questions from gate or net exam and teach it clearly madam

[@shashikalaraju5769]

Please tell me what's that matrix you've written under Relation. What does it mean?

[@shashikalaraju5769]

Oh...that's the table. Okay

[@Mandeepsingh-jo5cf]

Thanks mam.

[@himavarshareddy4153]

Mam can u please make a video on multivalued dependencies

[@SHIVAMGUPTA-kl5gk]

nice explanation mam,but upload more video very soon please

[@shubhamchavan7828]

make a series on SQL

[@nubmidnight8543]

Mam please make videos on C language ... Please mam

[@SaravaniJawahar]

yes mam

[@chetanraj7974]

Hii mam , would you like to have dinner ? Final year student at IIT Kanpur

[@shekhar5599]

Jantey ho mam...mai yahi soch rha itney padhe likhey larki se sadi karne k liye . . . Kitna padhna parega.... and kash bachpan me mai English movie bina MUTE kiye dekhta to aaj mai puri class me sirf apko dekhta nhi balki sunta v....

[@devimadhumitha018]

🎉

[@NaveenKumar-os8dv]

15:32. This is wrong. You must not use this method. We don't do that for checking lossless join if R is divided into 3 or more relations. This is so wrong! I am telling guys. It works only if R is divided in 2 relations R1 and R2. For 3 or more relations, you should use "Chase Algorithm" to check for lossless join. Do some research on your own as well. Don't call any teacher god and praise them. Wrong concept was used here. Shocking that everyone is praising the wrong concept.

[@bonsugodfred801]

lecture 20 is missing

[@Aakash-p7x]

No it's just shuffled wrongly

[@ritvikdabas2436]

Mam plss guide me for dsssb tgt cs plss🙏

[@amitjajoo9510]

Ma'am upload more video

[@deepakkumarsaroj5374]

I am NEET aspirant but I don't know why I am here during my chemistry class 😎😎शायद ठरक 😜😜

[@ahmadabbas1836]

Mam ka no. Hai 7392810252

[@puspendudebnath2533]

uffffff Those eyes 🙈