In an ER model,_____ is described in the database by storing its data.
Entity
Attribute
Relationship
Notation
Correct Answer :
A. Entity
Related Questions
DBMS helps achieve
Centralized control of data
Data independence
Both A and B
Neither A nor B
In a relational schema, each tuple is divided into fields called
Relations
Queries
Domains
All of the above
Which normal form is considered adequate for normal relational database design?
2NF
5NF
4NF
3NF
Relational Algebra does not have
Selection operator.
Projection operator.
Aggregation operators.
Division operator.
Use of UNIQUE while defining an attribute of a table in SQL means that the attribute values are
distinct values
cannot have NULL
both (A) & (B)
same as primary key
The data models defined by ANSI/SPARC architecture are
Conceptual, physical and internal
Conceptual, view and external
Logical, physical and internal
Logical, physical and view
The clause alter table in SQL can be used to
add an attribute
delete an attribute
alter the default values of an attribute
all of the above
The common column is eliminated in
theta join
outer join
natural join
composed join
The values of the attribute describes a particular
Entity set
File
Entity instance
Organization
Which two files are used during operation of the DBMS?
Query languages and utilities
DML and query language
Data dictionary and transaction log
Data dictionary and query language
Which of the following is not a recovery technique?
Deferred update
Immediate update
Two-phase commit
Shadow paging
The size of a data item is called its _______, which can be a field of some record or may be a larger unit such as a record.
Similarity
Granularity
Dimensionality
Arity
A transaction is in state after the final statement has been executed.
partially committed
active
committed
none of the above
Precedence graphs help to find a
Serializable schedule.
Recoverable schedule.
Deadlock free schedule.
Cascadeless schedule.
DROP is a statement in SQL.
Query
Embedded SQL
DDL
DCL
Whenever two independent one-to-many relationships are mixed in the same relation, a __________ arises.
Functional dependency
Multi-valued dependency
Transitive dependency
Partial dependency
The default level of consistency in SQL is
repeatable read
read committed
read uncommitted
serializable
When an E-R diagram is mapped to tables, the representation is redundant for
weak entity sets
weak relationship sets
strong entity sets
strong relationship sets
Given the following relation S(SNO,SNAME,CITY) write a query to update the value of CITY to KANPUR for the supplier S1.
UPDATE S CITY = KANPUR WHERE SNO=S1
UPDATE S SET CITY = KANPUR FOR SNO=S1
UPDATE S SET CITY = KANPUR WHERE SNO=S1
UPDATE S RENAME CITY = KANPUR WHERE SNO=S1
For correct behaviour during recovery, undo and redo operation must be
Commutative
Associative
idempotent
distributive
Which of the following statement on the view concept in SQL is invalid?
All views are not updateable
The views may be referenced in an SQL statement whenever tables are referenced.
The views are instantiated at the time they are referenced and not when they are defined.
The definition of a view should not have GROUP BY clause in it.
In 2NF
No functional dependencies (FDs) exist.
No multivalued dependencies (MVDs) exist.
No partial FDs exist.
No partial MVDs exist.
The relational model is based on the concept that data is organized and stored in two-dimensional tables called ______
Fields
Records
Relations
Keys
If two relations R and S are joined, then the non matching tuples of both R and S are ignored in
left outer join
right outer join
full outer join
inner join
Checkpoints are a part of
Recovery measures.
Security measures.
Concurrency measures.
uthorization measures.
The one guideline to be followed while designing the database is
A database design may be ambiguous.
It should avoid/reduce the redundancy.
Unrelated data should be in the same table so that updating the data will be easy.
An entity should not have attributes.
The part of a database management system which ensures that the data remains in a consistent state is
authorization and integrity manager
buffer manager
transaction manager
file manager
Which of the following concurrency control schemes is not based on the serializability property?
Two - phase locking
Graph-based locking
Time-stamp based locking
None of these .
A data type or format is specified for each _________
Relation
Tuple
Database
Domain
Which one is true statement :
With finer degree of granularity of locking a high degree of concurrency is possible.
Locking prevents non-serializable schedules.
Locking cannot take place at field level.
An exclusive lock on data item X is granted even if a shared lock is already held on X.