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Recent questions tagged natural-join

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DBMS Join | Test Series | MadeEasy
In relational databases, the natural join of two tables: Can be equivalent to cartesian product of these two tables Is combination of union and filtered cartesian product Is combination of selection and filtered cartesian product Is combination of projection and filtered cartesian product MSQ Please describe your choice(s).

anupamsworld asked in Databases Aug 7, 2022

by anupamsworld

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1 vote

1 answer

2

conditional join, DBMS, projection operator
why don't we use the projection operator in conditional join?

raginibhayana asked in Databases Feb 16, 2022

by raginibhayana

480 views

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0 answers

3

Natural Join Self Doubt
how to write the query for natural join on three relations in SQL using the NATURAL JOIN clause?

aditi19 asked in Databases May 8, 2019

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1 answer

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Molina Exercise-6.2.2 page-267 SQL
Product(maker, model, type) PC(model, speed, ram, hd, price) Laptop(model, speed, ram, hd, screen, price) Find those manufacturers of at least two different computers (PC's or laptops) with speeds of at least 3.0 is my query ... AND count(distinct model)>=2 UNION select maker from Product NATURAL JOIN Laptop where speed>=3 AND count(distinct model)>=2

aditi19 asked in Databases May 7, 2019

1.2k views

1 vote

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MadeEasy CBT Test 2019: Databases - Natural Join

singh chetan asked in Databases Jan 28, 2019

by singh chetan

601 views

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1 answer

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Natural Join
Suppose we have 2 tables R1(ABCD), R2(DE) . R1 has 500 entries whereas R2 has 1500 entries. Here D is a candidate key. If we join them using natural join. How many entires would be there in the resultant table and why ? Examples would be appreciated..

Shamim Ahmed asked in Databases Jan 8, 2019

by Shamim Ahmed

424 views

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0 answers

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JOIN (Natural join)
In a natural join, the common attribute occur only once, but in join https://gateoverflow.in/3718/gate2004-it-74 Select * from Student, Department in this common, attribute we have given m+n I tried in w3 schools https://www.w3schools.com/sql/ ... * FROM Orders, Customers WHERE City='Berlin' AND OrderID = '10248' here common attribute is occuring only once, PLease guide .

Learner_jai asked in Databases Dec 14, 2018

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Database Management System
If NO ATTRIBUTES are common in both relations (R and S) then the result of natural join is ?? a. Empty relation. b. Cartesian Product of the relations.

cidacoder asked in Databases Dec 8, 2018

179 views

1 vote

1 answer

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Database
consider $r1(A,B,C),r2(C,D,E)$ and $r3(F,G)$ with primary key $A,C,F, r1$ has $150 ,r2$ has $100$ and $r3$ has $75$ tuples the number of tuples in $r1$ natural join $r2$ natural join $r3?$

Abhisek Tiwari 4 asked in Databases Nov 30, 2018

by Abhisek Tiwari 4

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JOIN Doubt
in case of outer join for combining two tables, if there is no common attribute does it returns cartesian product just like natural join does?

aditi19 asked in Databases Nov 2, 2018

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#book
A B C 1 a c 2 b b 3 c a 4 c c A B D 1 a a 1 b b 3 c c 4 c d these are two table R AND S FIND NATURAL JOIN(*)

amit166 asked in Databases Nov 1, 2018

109 views

1 vote

1 answer

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ISI2017-PCB-CS-3-a
Let $R(A,B,C)$ be a relation with primary key $(A)$ and $S(A, D, E)$ a relation with primary key $(A, D)$. Each of the relations has $n$ tuples. If the number of tuples in $R \: \text{ natural join } S$ is $m$, then determine the number of tuples in $R$ $\text{ natural left outer join } S$.

go_editor asked in Databases Sep 20, 2018

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TestSeries
Consider two relations R(A, B, C) and S(B, D) with R contains 5000 tupples stored in a sequential file sorted on attribute A and S contain 100000 tupples stored in a sequential file sorted on attribute B. Each block can hold 10 R tupples or 10 S tupples. Which one of the following index is most appropriate for answering query (Assume index always stored in memory)

syncronizing asked in Databases Aug 19, 2018

by syncronizing

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14

Natural Join
Consider two relations R(A, B, C) and S(B, D) with R contains 5000 tuples stored in a sequential file sorted on attribute A and S contain 100000 tuples stored in a sequential file sorted on attribute B. Each block can hold 10 R tuples or 10 S tuples. Which one of the following index is most appropriate for answering query R (natural Join) S (Assume index always stored in memory)

Na462 asked in Databases Jul 14, 2018

by Na462

580 views

5 votes

1 answer

15

MadeEasy Test Series: Databases - Natural Join
Consider a relation r1(A, B, C), r2(C, D, E) and r3(F, G) with primary keys A, C and F respectively. Assume that r1 has 150 tupples, r2 has 100 tupples and r3 has 75 tupples. The number of resultant tuple in are ________.

Na462 asked in Databases Jun 14, 2018

by Na462

3.6k views

2 votes

3 answers

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MadeEasy Test Series: Databases - Relational Algebra
Consider relation R' and S' have n' and m' tuples, respectively. Choose the best matching between List-I (Expression) and List-II (Maximum number of tuple): Soln. According to me Answer should be Option C. 1.R union S = m+n (easy nothing to say) 2. ... 2 3 3 3 5 4 3 3 3 6 Now in R natual join S = m * n So option C should suffice isn't it ?

Na462 asked in Databases Jun 14, 2018

by Na462

2.0k views

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2 answers

17

Theta Join
When we do natural join say between R1(A,B,C) and R2(A,B,D) we get new Relation as ---> R(A,B,C,D) Say if we do Theta join using a Predicate P then the result will be ----> R(A,B,C,A,B,D) Am i right?

Na462 asked in Databases May 17, 2018

by Na462

336 views

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0 answers

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Understanding theta join operation
Q.1. Does theta join operator requires following union compatibility requirements?: Same number of columns Domain of corresponding columns should be same I feel no, since I came across following fact: $\sigma_\theta( R_1\times R_2)=R_1⋈_\theta R_2$ ... as shown above, does it mean columns of resultant relation will contain ALL columns from both $R_1$ and $R_2$?

GateAspirant999 asked in Databases May 12, 2018

by GateAspirant999

516 views

2 votes

0 answers

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Made easy test series2019 database
Consider two relations R(A, B, C) and S(B, D) with R contains 5000 tupples stored in a sequential file sorted on attribute A and S contain 100000 tupples stored in a sequential file sorted on attribute B. Each block can hold 10 R tupples or 10 S tupples. Which one of ... A A dense index on R.B B A sparse index on R.B C A dense index on S.B D A sparse index on S.B

visakh v asked in Databases May 4, 2018

274 views

1 vote

1 answer

20

Natural join
My answer is not matching with any of the option.so what is the correct answer

learner_geek asked in Databases Jan 24, 2018

by learner_geek

1.0k views

1 vote

1 answer

21

Natural Join
If a question asks anything about 'Join' without describing what sort of join it is, should I consider that as a cross product join or Natural Join? (PS: As far as my knowledge goes, Natural join is almost equivalent to Inner Join and not Cross product.) Refer this question : https://gateoverflow.in/1471/gate1999-1-18-isro2016-53

Warlock lord asked in Databases Jan 9, 2018

by Warlock lord

222 views

1 vote

0 answers

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MadeEasy Test Series: Databases - Natural Join
the answer should be 50 right?

Kalpataru Bose asked in Databases Jan 1, 2018

by Kalpataru Bose

303 views

0 votes

0 answers

23

Number of tuples
Consider the relation schema: Student(roll no, name course no) Enroll(roll no, course no,course name) The number of tuples in the student and enroll table is 30 and 40 respectively The natural join is performed on roll no., what is max. and min. no. of tuples that are possible?

srestha asked in Databases Dec 16, 2017

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DBMS Losless join
R is divided into R1 and R2 ,but since there is no common attribute in R1 and R2, so it should form lossy join,as for loseless join the common attribute has to be key in one of the table.But here the image above,it is comming as loseless join.Can someone please check?

rahul sharma 5 asked in Databases Dec 12, 2017

by rahul sharma 5

283 views

3 votes

2 answers

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#DBMS What will be the Minimum Number of Tuples?
Say we have two relations R (a,b,c) and S (b,d,e). Now, R has 200 tuples and S has 300 tuples. What will be Minimum number of tuples when we do R ⋈ S ( ⋈ = Natural Join)?

iarnav asked in Databases Dec 6, 2017

by iarnav

848 views

2 votes

1 answer

26

#DBMS Natural Join
Please kindly explain Natural Join by taking your own handmade example in layman terms. Thank you!

iarnav asked in Databases Nov 27, 2017

by iarnav

1.1k views

1 vote

0 answers

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DBMS SELF DOUBT
Let R and S be two relations with the following schema R(P−−,Q−−,R1,R2,R3) S(P−−,Q−−,S1,S2) where {P,Q} is the key for both schemas? R:{⟨"1","abc","p1","p2","p3"⟩, ⟨"2","xyz", ... ;,"q3"⟩ ⟨"2","def","q1","q2","q3"⟩ WHat is R *S? WHERE * IS NATURAL JOIN.

iarnav asked in Databases Nov 27, 2017

by iarnav

393 views

3 votes

1 answer

28

Database: equijoin v/s natural join
Which one is the more suitable answer for the following question, equijoin or natural join?

Manu Thakur asked in Databases Oct 25, 2017

827 views

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0 answers

29

equi natural inner join
Can we say inner and self join are same ?

set2018 asked in Databases Sep 29, 2017

223 views

2 votes

2 answers

30

Block Nested Loop Join
Consider a relation R with 2000 records and relation S with 500 records. Size of each record is 5 Byte and block size is 100 Byte, then minimum number of block access that are needed block nested loop join. I think its answer should be 2525.

Shubhanshu asked in Databases Aug 18, 2017

956 views

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Recent questions tagged natural-join