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.
Correct Answer :
A. With finer degree of granularity of locking a high degree of concurrency is possible.
Related Questions
The values of the attribute describes a particular
Entity set
File
Entity instance
Organization
Protection of data from unauthorized Disclosure results in loss of _______
Integrity
Availability
Confidentiality
Discretionary Security
Data independence means
data is defined separately and not included in programs.
programs are not dependent on the physical attributes of data
programs are not dependent on the logical attributes of data
both B and C
Drop Table cannot be used to drop a table referenced by a ______ constraint.
Primary Key
Local Key
Foreign Key
Composite Key
The rule that a value of a foreign key must appear as a value of some specific table is called a
Referential constraint.
Index.
Integrity constraint.
Functional dependency.
In 2NF
No functional dependencies (FDs) exist.
No multivalued dependencies (MVDs) exist.
No partial FDs exist.
No partial MVDs exist.
An advantage of views is
Data security
Derived columns
Hiding of complex queries
All of the above
Relational Algebra is
Data Definition Language .
Meta Language
Procedural query Language
None of the above
The clause in SQL that specifies that the query result should be sorted in ascending or descending order based on the values of one or more columns is
View
Order by
Group by
Having
A ______ module is typically designed so that it will run on a user workstation or personal computer.
Software
Server
Program
Client
Relationships among relationships can be represented in an-E-R model using
Aggregation
Association
Weak entity sets
Weak relationship sets
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.
A weak entity has an ______ dependency on its owner entity, which can be used for both ON UPDATE and ON DELETE.
Direct
Indirect
Existence
No
Grant and revoke are _____ statements.
TCL
DCL
DDL
DML
Processed data is called _____
Raw data
Source
Information
Useful data
The set of all values that can be taken by the attribute is called as _______ of the attribute.
Tuple
Cardinality
Degree
Domain
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 collection of information stored in a database at a particular moment is called as ......
schema
instance of the database
data domain
independence
What is a disjoint less constraint?
It requires that an entity belongs to no more than one level entity set.
The same entity may belong to more than one level.
The database must contain an unmatched foreign key value.
An entity can be joined with another entity in the same level entity set.
The statement that is executed automatically by the system as a side effect of the modification of the database is
backup
assertion
recovery
trigger
A logical schema
is the entire database
Describes how data is actually stored on disk.
is a standard way of organizing information into accessible parts.
All of the above
______contains information that defines valid values that are stored in a column or data type.
Default
Index
Rule
View
The _____ category includes storage media that can be operated on directly by the computers central processing unit.
Primary storage
Secondary Storage
All
Tertiary Storage
The division operator divides a dividend A of degree m+n by a divisor relation B of degree n and produces a result of degree
m - 1
m + 1
m * m
m
_____ database is used to provide statistical information or summaries of values based on various criteria.
Statistical
Mathematical
Normalized
Un normalized
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
The middleware databases in which the business rules act are applicable to _______ tier architectures
Single
Three
Two
None
The data in the database at a particular moment of time is called the _______
Snapshot
Dynaset
Stateless
Stateful
Which of the following is not a consequence of concurrent operations?
Lost update problem.
Update anomaly.
Unrepeatable read.
Dirty read.
In a multi-user database, if two users wish to update the same record at the same time, they are prevented from doing so by
jamming
password
documentation
record lock