PPSC FPSC KPPSC BPSC SPSC Lecturer Computer Science Test 51

Leave a Comment / By Hassan / December 25, 2021

Online Free Taleem is free online MCQ’s test related to Lecturer Computer Science. All the individuals who are going to appear in Lecturer Computer Science written test can attempt these tests in order to prepare for it in best possible way. Our tests of Lecturer of Computer Science include all the important questions and Past Paper of Lecturer Computer Science, that have extremely high amount of chances for been included in the actual exam which make our test undoubtedly the best source of preparation.

Note:-

There will be 25 multiple choice question in the test.
Answer of the questions will change randomly each time you start this test.
Practice this test at least 5 times if you want to secure High Marks.
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Test Instructions:-
Test Name	Lecturer Computer Science
Subject	Computer Science Test 51
Test Type	MCQs
Total Questions	25
Total Time	20 Minutes
Total Marks	100

You have 20 minutes to pass to the quiz.

Lecturer Computer Science Online Test No. 51

1 / 25

Which of the following syntax of the basic query is correct?

select from

2 / 25

To specify the foreign keys in relations referencing temporal data we need to specify......

The time interval

The Boolean value for the working

The integer corresponding to the relation number

None of these

3 / 25

What does the ―x‖ operator do in relational algebra?

Output specified attributes from all rows of the input relation. Remove duplicate tuples from the output

Output pairs of rows from the two input relations that have the same value on all attributes that have the same name

Output all pairs of rows from the two input relations (regardless of whether or not they have the same values on common attributes)

Returns the rows of the input relation that satisfy the predicate

4 / 25

What action does ⋈ operator perform in relational algebra:

Output specified attributes from all rows of the input relation and remove duplicate tuples from the output

Outputs pairs of rows from the two input relations that have the same value on all attributes that have the same name

Output all pairs of rows from the two input relations (regardless of whether or not they have the same values on common attributes)

Return rows of the input relation that satisfy the predicate

5 / 25

Which of the following is the time of temporal data that record when a fact was recorded in a database?

Transaction time

Valid time

Enter time

Exit time

6 / 25

What is an Instance of a Database?

The logical design of the database system

The entire set of attributes of the Database put together in a single relation

The state of the database system at any given point of time

The initial values inserted into the Database immediately after its creation

7 / 25

If database modifications occur while the transaction is still active, the transaction is said to use the ________technique.

Deferred-modification

Late-modification

Immediate-modification

Undo

8 / 25

The current copy of the database is identified by a pointer, called __________, which is stored on disk.

Db-pointer

Update log

Update log records

All of these

9 / 25

What is a foreign key?

A foreign key is a primary key of a relation which is an attribute in another relation

A foreign key is a superkey of a relation which is an attribute in more than one other relations

A foreign key is an attribute of a relation that is a primary key of another relation

A foreign key is the primary key of a relation that does not occur anywhere else in the schema

10 / 25

In the _______ phase, the system replays updates of all transactions by scanning the log forward from the last checkpoint.

Repeating

Redo

Replay

Undo

11 / 25

.............using a log record sets the data item specified in the log record to the old value.

Deferred-modification

Late-modification

Immediate-modification

Undo

12 / 25

The ________ scheme uses a page table containing pointers to all pages; the page table itself and all updated pages are copied to a new location.

Shadow copy

Shadow Paging

Update log records

All of these

13 / 25

The data that have a time interval associated with them during which they are valid are called as........

Timed data

Temporal data

Model data

Clocked data

14 / 25

In the _______ scheme, a transaction that wants to update the database first creates a complete copy of the database.

Shadow copy

Shadow Paging

Update log records

All of these

15 / 25

The log is a sequence of _______, recording all the update activities in the database.

Log records

Records

Entries

Redo

16 / 25

The value of the data at a particular time is called as?

Instance

Picture

Snapshot

None of these

17 / 25

The actions which are played in the order while recording it is called __________ history.

Repeating

Redo

Replay

Undo

18 / 25

Choose the correct statement regarding superkeys:

A superkey is an attribute or a group of multiple attributes that can uniquely identify a tuple

A superkey is a tuple or a set of multiple tuples that can uniquely identify an attribute

Every superkey is a candidate key

A superkey is an attribute or a set of attributes that distinguish the relation from other relations

19 / 25

Which of the following keywords is used beside the select clause to explicitly specify that duplicates are not removed?

all

not unique

notnull

include

20 / 25

A special redo-only log record is written to the log, where V1 is the value being restored to data item Xj during the rollback. These log records are sometimes called:

Log records

Records

Compensation log records

Compensation redo records

21 / 25

The process of making a normalized schema unnormalized is called as.........

Unnormalization

Denormalization

Renormalization

Annormalization

22 / 25

An attribute is a _________ in a relation.

Row

Column

Value

Tuple

23 / 25

What is the method of specifying a primary key in a schema description?

By writing it in bold letters

By underlining it using a dashed line

By writing it in capital letters

By underlining it using a bold line

24 / 25

Functional dependencies that have a time associated with them during which they are valid are called as.......

Timed functional dependencies

Clocked functional dependencies

Temporal functional dependencies

Modeled functional dependencies

25 / 25

If a transaction does not modify the database until it has committed, it is said to use the ________ technique.

Deferred-modification

Late-modification

Immediate-modification

Undo

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PPSC FPSC KPPSC BPSC SPSC Lecturer Computer Science Test 51

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