adplus-dvertising
frame-decoration

Question

An entity instance is a single occurrence of an …………..

a.

entity type

b.

relationship type

c.

entity and relationship type

d.

None of these

Answer: (a).entity type

Engage with the Community - Add Your Comment

Confused About the Answer? Ask for Details Here.

Know the Explanation? Add it Here.

Q. An entity instance is a single occurrence of an …………..

Similar Questions

Discover Related MCQs

Q. Generalization is ………… process.

Q. Match the following:

Set-I
I. 2 NF
II. 3 NF
III. 4 NF
IV. 5 NF

Set-II
(a) transitive dependencies eliminated
(b) multivalued attribute removed
(c) contain no partial functional dependencies
(d) contains no join dependency

Codes :
    I    II   III   IV

Q. Which data management language component enabled the DBA to define the schema components?

Q. The PROJECT Command will create new table that has

Q. A chained hash table has an array size of 100. What is the maximum number of entries that can be placed in the table?

Q. The E-R model is expressed in term of

I. Entities
II. The relationship among entities.
III. The attributes of the entities.
IV. Functional relationship.

Q. Specialization is …………… process.

Q. Match the following :

List-I
(1) Determinants
(2) Candidate key
(3) Non-redundancy
(4) Functional dependency

List-II
(a) No attribute can be added
(b) Uniquely identified a row
(c) A constraint between two attribute
(d) Group of attributes on the left hand side of arrow of function dependency.

Q. A function that has no partial functional dependencies is in ……………. form.

Q. Which of the following statement is wrong?

I. 2-phase locking protocol suffer from dead lock.
II. Time stamp protocol suffer from more aborts.
III. A block hole in a DFD is a data store with only inbound flows.
IV. Multivalued dependency among attribute is checked at 3 NF level.
V. An entity-relationship diagram is a tool to represent event model.

Q. The name of the transaction file shall be provided by the operator and the file that contains the edited transactions ready for execution shall be called

Q. (i) DML includes a query language based on both relation algebra and tuple calculus
(ii) DML includes a query language based on tuple calculus
(iii) DML includes a query language based on relational algebra
(iv) DML includes a query language based on none of the relational algebra and tuple calculus

Which one is correct?

Q. Which construct in SQL is used to test whether a subquery has any tuples in its result?

Q. An entity has:

(i) a set of properties
(ii) a set of properties and values for all the properties
(iii) a set of properties and the values for some set of properties may non-uniquely identify an entity
(iv) a set of properties and the values for some set of properties may uniquely identify an entity

Which of the above are valid?

Q. Aggregation is:

Q. Suppose R is a relation schema and F is a set of functional dependencies on R. Further, suppose R1 and R2 form a decomposition of R. Then the decomposition is a lossless join decomposition of R provided that:

Q. In a heap, every element is …………… of all the elements in the subtree.

Q. A superkey for an entity consists of:

Q. Which of the following set of keywords constitutes a mapping in SQL?

Q. If a relation is in 2NF then: