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Recent questions tagged rdbms

2 votes

0 answers

31

database
what is the concept of nested loop join in database????????? link plz or give any example.

akankshadewangan24 asked in Databases Jan 12, 2018

by akankshadewangan24

185 views

0 votes

1 answer

32

ankitgupta.1729 asked in Databases Dec 16, 2017

by ankitgupta.1729

380 views

0 votes

1 answer

33

Number of tables
Number of tables required and also the attribute set of the tables

Mk Utkarsh asked in Databases Dec 11, 2017

401 views

3 votes

1 answer

34

MadeEasy Test Series: Databases - Er Diagram
In the solution they have merged E1 R4 E4 , E2 R3 E3 R5 , R6 E5. MY DOUBT IS , why cant we only merge R4 E4 instead of E1 R4 E4. since there is total participation on the E4 side of the relation and it would also decrease the number of attributes .

shaurya vardhan asked in Databases Dec 4, 2017

by shaurya vardhan

1.2k views

0 votes

1 answer

35

database self doubt
what does this line means - Let r and s be two relations over the relation schemes R and S respectively and R has attribute A.

iarnav asked in Databases Nov 27, 2017

by iarnav

431 views

6 votes

2 answers

36

One to one relationship with total participation of one entity. Can a single table be formed?
I am confused whether we need to have 2 tables or a single table when 2 strong entities are in 1:1 relationship with one having complete participation. Ex: How is it possible that we join Person and ... Bank Account may refer to some of the Person records which may go away on joining Person and License.

Ashish Sharma 3 asked in Databases Nov 24, 2017

by Ashish Sharma 3

12.8k views

5 votes

1 answer

37

Minimum relations required for ER diagram
How many minimum relations required for the above ER diagram? According to me it should be 7. Please let me know the answer according to you.

Ashish Sharma 3 asked in Databases Nov 24, 2017

by Ashish Sharma 3

2.7k views

1 vote

5 answers

38

UGC NET CSE | November 2017 | Part 3 | Question: 12
Consider a schema $R(A, B, C, D)$ and following functional dependencies. $A \rightarrow B$ $B \rightarrow C$ $C \rightarrow D$ $D \rightarrow B$ Then decomposition of $R$ ... preserving and lossless join Lossless join but dependency preserving Dependency preserving but not lossless join Not dependency preserving and not lossless join

Arjun asked in Databases Nov 5, 2017

by Arjun

3.5k views

2 votes

1 answer

39

UGC NET CSE | November 2017 | Part 3 | Question: 10
Consider a relation $R (A, B, C, D, E, F, G, H)$ where each attribute is atomic, and following functional dependencies exist. $ CH \rightarrow G$ $A \rightarrow BC$ $B \rightarrow CFH$ $E \rightarrow A$ $F \rightarrow EG$ The relation $R$ is ________ In $1NF$ but not in $2NF$ In $2NF$ but not in $3NF$ In $3NF$ but not in $BCNF$ In $BCNF$

Arjun asked in Databases Nov 5, 2017

by Arjun

4.6k views

0 votes

1 answer

40

Database doubt
Why B or B+ tree is prefer for database indexing rather than AVL tree ????

air1ankit asked in Databases Oct 28, 2017

347 views

0 votes

0 answers

41

Database #1NF
R(ABCDE) { A,BC,CD} are candidate key of relation R after 1 NF design which one is possible multi valued attributes before 1 NF design ???

air1ankit asked in Databases Oct 27, 2017

470 views

4 votes

1 answer

42

Doubt Database
What is difference between attributes set of cross product and attributes set of joine ???

air1ankit asked in Databases Oct 22, 2017

577 views

1 vote

1 answer

43

Doubt database
What is basic difference between mandatory attributes and multivalued attributes???

air1ankit asked in Databases Oct 19, 2017

301 views

0 votes

0 answers

44

Participation constraints
For what type of relationships we can't have participant constraints? I mean from unary, binary and ternary relationship is there any that we can't specify a participation constraint.

V MIDHUN 2 asked in Databases Aug 30, 2017

469 views

0 votes

1 answer

45

ERDiagram conversion to Database
Suppose i have Two strong entity E1 and E2 connected by a 1 to many relationship R. E1 <--------- R ---------- E2 How many table will be created when i will convert the above ER diagram into database ? I know that when E2 ... above. I have seen multiple places and found different answer. I am looking for some solid argument with answer. Answer can be 2 or 3.

lifeisshubh asked in Databases Jan 21, 2017

450 views

1 vote

2 answers

46

ER to Table Conversion
Any Good Resource to study this topic ? Or Could anyone explain this topic to me ?

PEKKA asked in Databases Nov 29, 2016

by PEKKA

1.4k views

1 vote

1 answer

47

ER to Relational mapping
How can trainer id be p.key of Parts??

KISHALAY DAS asked in Databases Oct 19, 2016

by KISHALAY DAS

1.5k views

0 votes

2 answers

48

UGC NET CSE | August 2016 | Part 2 | Question: 18
Consider the following statements regarding relational database model : (a) NULL values can be used to opt a tuple out of enforcement of a foreign key. (b) Suppose that table T has only one candidate key. If Q is in $3$NF, then it is also in BCNF. (c) The ... ) are true. (a) and (c) are true. (b) and (c) are true. (a), (b) and (c) are true.

makhdoom ghaya asked in Others Sep 24, 2016

by makhdoom ghaya

3.1k views

0 votes

1 answer

49

UGC NET CSE | August 2016 | Part 2 | Question: 16
DBMS provides the facility of accessing data from a database through DDL DML DBA Schema

makhdoom ghaya asked in Others Sep 24, 2016

by makhdoom ghaya

1.4k views

4 votes

1 answer

50

UGC NET CSE | June 2016 | Part 2 | Question: 18
In a relational database model, NULL values canbe used for all but which one of the following? To allow duplicate tuples in the table by filling the primary key column(s) with NULL To avoid confusion with actual legitimate data ... is unknown To fill a column in a tuple when that column does not really "exist" for that particular tuple

go_editor asked in Databases Aug 14, 2016

4.7k views

4 votes

1 answer

51

UGC NET CSE | June 2016 | Part 2 | Question: 16
In RDBMS, the constraint that no key attribute (column) may be NULL is referred to as: Referential integrity Multi-valued dependency Entity integrity Functional dependency

go_editor asked in Databases Aug 14, 2016

2.6k views

3 votes

2 answers

52

UGC NET CSE | June 2013 | Part 3 | Question: 34
Horn clauses are special kinds of propositions which can be described as Single atomic proposition on left side Single or multiple atomic proposition on left side A single atomic proposition on left side and a single atomic proposition on right side A single atomic proposition on left side or an empty left side

go_editor asked in Databases Jul 17, 2016

2.4k views

0 votes

1 answer

53

UGC NET CSE | June 2013 | Part 3 | Question: 7
The “PROJECT” operator of a relational algebra creates a new table that has always More columns than columns in original table More rows than original table Same number of rows as the original table Same number of columns as the original table

go_editor asked in Databases Jul 16, 2016

3.2k views

3 votes

2 answers

54

ISRO2011-21
Which type of DBMS provides support for maintaining several versions of the same entity? Relational Database Management System Hierarchical Object Oriented Database Management System Network

Isha Gupta asked in Databases Jun 15, 2016

3.7k views

6 votes

4 answers

55

ISRO2007-50
A view of database that appears to an application program is known as Schema Subschema Virtual table None of these

go_editor asked in Databases Jun 10, 2016

13.1k views

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Recent questions tagged rdbms