The default level of consistency in SQL is
repeatable read
read committed
read uncommitted
serializable
Correct Answer :
D. serializable
Related Questions
Which of the following is not a recovery technique?
Deferred update
Immediate update
Two-phase commit
Shadow paging
The cost of reading and writing temporary files while evaluating a query can be reduced by
building indices
pipelining
join ordering
none of the above
Which is the best file organization when data is frequently added or deleted from a file?
Sequential
Direct
Index sequential
None of the above
In SQL, testing whether a subquery is empty is done using
DISTINCT
UNIQUE
NULL
EXISTS
The ____ operator joins two or more conditions and displays rows only if that rows data satisfies all conditions specified.
OR
AND
NOT
ALL
Isolation of the transactions is ensured by
Transaction management
Application programmer
Concurrency control
Recovery management
The full form of GUI is _________
Government Union Internet
Graphical Unit Interface
Graphical User Interface
Graphical University Interface
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 fact that information in the data warehouse changes far less often and may be regarded as non-real-time with periodic updating; This implies that data warehouses are _______
Volatile
Non - Volatile
Logical
Physical
A relation is in attribute of other composite key. if an attribute of a composite key is dependent on an
2NF
3NF
BCNF
1NF
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.
A relational database developer refers to a record as
an attribute
a tuple
a criteria
a relation
Dependency preservation is not guaranteed in
BCNF
3NF
PJNF
DKNF
Whenever two independent one-to-many relationships are mixed in the same relation, a __________ arises.
Functional dependency
Multi-valued dependency
Transitive dependency
Partial dependency
If a transaction T has obtained an exclusive lock on item Q, then T can
read Q
write Q
both read and write Q
write Q but not read Q
As per equivalence rules for query transformation, selection operation distributes over
Union.
Set difference.
Intersection.
All of the above.
The graphical representation of a query is .
B-Tree
graph
Query Tree
directed graph
If the closure of an attribute set is the entire relation then the attribute set is a
superkey
candidate key
primary key
not a key
………………… approach reduces time and effort required for design and lesser risk in database management.
Single global database
Multiple databases
Top-down approach
None of the above
Which of the following is not comparison operator?
<>
<
=<
>=
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 data type or format is specified for each _________
Relation
Tuple
Database
Domain
Which of the following ensures the atomicity of the transaction?
Transaction management component of DBMS
Application Programmer
Concurrency control component of DBMS
Recovery management component of DBMS
Employees in a company are each assigned their own office, i.e. for each employee there exists a unique office and for each office there exists a unique employee; This statement is an example of ____ type of relation.
1:1
1: Many
Many: One
Many : Many
A top-to-bottom relationship among the items in a database is established by a
Hierarchical schema
Network schema
Relational Schema
All of the above
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 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
The normalization was first proposed by .
Code
Codd
Boyce Codd
Boyce
Immediate database modification technique uses
Both undo and redo.
Undo but no redo.
Redo but no undo.
Neither undo nor redo.
_______ product was acquired by Informix, integrated into its RDBMS and introduced as the Informix Universal Server an ORDBMS.
Star
llustar
SQL
Cygnus