Please keep at least one language enabled. || కనీసం ఒక భాషను ఎంచుకోండి.
Question 1
ప్రశ్న 1
In the relational model, which term refers to the structure that is commonly represented as a two-dimensional table of rows and columns?
Select an option first. || ముందుగా ఒక సమాధానాన్ని ఎంచుకోండి.
Explanation:
• A relation is the fundamental data structure of the relational model and is commonly represented as a table.
• Its rows correspond to tuples and its columns correspond to attributes.
• A record represents one row, while a domain specifies valid values for an attribute.
• Its rows correspond to tuples and its columns correspond to attributes.
• A record represents one row, while a domain specifies valid values for an attribute.
వివరణ:
Question 2
ప్రశ్న 2
An EMPLOYEE relation contains the row (105, 'Ravi', 'Hyderabad', 'Inspector'). In formal relational terminology, what is this complete row called?
Select an option first. || ముందుగా ఒక సమాధానాన్ని ఎంచుకోండి.
Explanation:
• A tuple is one complete row of a relation and contains values corresponding to the relation's attributes.
• In practical database terminology, a tuple is also commonly called a row or record.
• The individual named characteristics such as Employee_ID and City are attributes.
• In practical database terminology, a tuple is also commonly called a row or record.
• The individual named characteristics such as Employee_ID and City are attributes.
వివరణ:
Question 3
ప్రశ్న 3
A PERSON table contains columns Person_ID, Name, Date_of_Birth and City. In formal relational terminology, what is Date_of_Birth?
Select an option first. || ముందుగా ఒక సమాధానాన్ని ఎంచుకోండి.
Explanation:
• An attribute represents a characteristic of the entity described by a relation.
• Attributes are represented as columns in the tabular representation of a relation.
• Date_of_Birth is therefore an attribute of the PERSON relation.
• Attributes are represented as columns in the tabular representation of a relation.
• Date_of_Birth is therefore an attribute of the PERSON relation.
వివరణ:
Question 4
ప్రశ్న 4
In common database terminology, a complete horizontal entry containing all stored details about one employee is called a:
Select an option first. || ముందుగా ఒక సమాధానాన్ని ఎంచుకోండి.
Explanation:
• A record is a collection of related fields describing one particular instance, such as one employee.
• In a table, a record is normally represented by a row.
• A field or column represents only one category of information within such records.
• In a table, a record is normally represented by a row.
• A field or column represents only one category of information within such records.
వివరణ:
Question 5
ప్రశ్న 5
In common database terminology, which table component is most closely associated with a field such as Employee_Name?
Select an option first. || ముందుగా ఒక సమాధానాన్ని ఎంచుకోండి.
Explanation:
• In common database usage, a field such as Employee_Name corresponds to a category of data represented by a column.
• Each record can contain a value for that field.
• A complete horizontal row represents a record rather than a single field.
• Each record can contain a value for that field.
• A complete horizontal row represents a record rather than a single field.
వివరణ:
Question 6
ప్రశ్న 6
In formal relational terminology, a relation contains the attributes Roll_No, Name, Course, Year, Mobile_No and District. What is the degree of this relation?
Select an option first. || ముందుగా ఒక సమాధానాన్ని ఎంచుకోండి.
Explanation:
• The degree, or arity, of a relation is the number of attributes in that relation.
• The listed relation has six attributes: Roll_No, Name, Course, Year, Mobile_No and District.
• Therefore its degree is 6.
• The listed relation has six attributes: Roll_No, Name, Course, Year, Mobile_No and District.
• Therefore its degree is 6.
వివరణ:
Question 7
ప్రశ్న 7
In formal relational terminology, a STUDENT relation currently contains 250 tuples. What is the cardinality of the relation?
Select an option first. || ముందుగా ఒక సమాధానాన్ని ఎంచుకోండి.
Explanation:
• In formal relational terminology, the cardinality of a relation is the number of tuples contained in it.
• A table with 250 tuples therefore has relation cardinality 250.
• This use of cardinality should be distinguished from the separate concept of relationship cardinality such as one-to-many.
• A table with 250 tuples therefore has relation cardinality 250.
• This use of cardinality should be distinguished from the separate concept of relationship cardinality such as one-to-many.
వివరణ:
Question 8
ప్రశ్న 8
In a STUDENT table, the row for Student_ID 120 contains 'Warangal' under the District column. What does 'Warangal' represent in that particular row-column intersection?
Select an option first. || ముందుగా ఒక సమాధానాన్ని ఎంచుకోండి.
Explanation:
• The intersection of a particular row and column contains the value of that attribute for that record.
• Here, 'Warangal' is the value of the District field for Student_ID 120.
• District is the attribute or column name, whereas 'Warangal' is the stored value.
• Here, 'Warangal' is the value of the District field for Student_ID 120.
• District is the attribute or column name, whereas 'Warangal' is the stored value.
వివరణ:
Question 9
ప్రశ్న 9
Which description best represents a relation schema rather than the current contents of a relation?
Select an option first. || ముందుగా ఒక సమాధానాన్ని ఎంచుకోండి.
Explanation:
• A relation schema describes the structure or definition of a relation rather than its current set of tuples.
• It identifies the relation and its attributes and associated structural definitions.
• The actual tuples stored at a particular time constitute the relation's current data.
• It identifies the relation and its attributes and associated structural definitions.
• The actual tuples stored at a particular time constitute the relation's current data.
వివరణ:
Question 10
ప్రశ్న 10
Which statement correctly describes the relationship between a table and its rows in a relational database?
Select an option first. || ముందుగా ఒక సమాధానాన్ని ఎంచుకోండి.
Explanation:
• A table commonly describes a subject or entity type, such as employees.
• Each row then represents one particular instance of that subject, such as one employee.
• Columns describe the attributes or characteristics stored about those instances.
• Each row then represents one particular instance of that subject, such as one employee.
• Columns describe the attributes or characteristics stored about those instances.
వివరణ:
Question 11
ప్రశ్న 11
A database administrator inserts 20 additional employee records into an existing EMPLOYEE table without adding or removing any columns. Which statement is correct?
Select an option first. || ముందుగా ఒక సమాధానాన్ని ఎంచుకోండి.
Explanation:
• Adding employee records inserts additional rows or tuples into the table.
• The table can gain rows without changing its existing set of columns or attributes.
• This illustrates the distinction between the table's structure and the data instances stored within it.
• The table can gain rows without changing its existing set of columns or attributes.
• This illustrates the distinction between the table's structure and the data instances stored within it.
వివరణ:
Question 12
ప్రశ్న 12
In the formal mathematical relational model, which statement about duplicate tuples is correct?
Select an option first. || ముందుగా ఒక సమాధానాన్ని ఎంచుకోండి.
Explanation:
• Formally, a relation is a set of tuples, and a mathematical set does not contain duplicate members.
• Therefore two completely identical tuples do not represent two distinct members of the same formal relation.
• This theoretical property should be distinguished from practical SQL query results, which can contain duplicate rows unless uniqueness is enforced or requested.
• Therefore two completely identical tuples do not represent two distinct members of the same formal relation.
• This theoretical property should be distinguished from practical SQL query results, which can contain duplicate rows unless uniqueness is enforced or requested.
వివరణ:
Question 13
ప్రశ్న 13
Which statement about the order of rows in a formal relational relation is correct?
Select an option first. || ముందుగా ఒక సమాధానాన్ని ఎంచుకోండి.
Explanation:
• A relation is conceptually a set of tuples, so inherent tuple ordering is not part of the formal relational model.
• A DBMS may display rows in a particular order, but that presentation should not be treated as an inherent relational property unless an ordering operation is explicitly applied.
• Reordering displayed rows does not change the relation's attributes.
• A DBMS may display rows in a particular order, but that presentation should not be treated as an inherent relational property unless an ordering operation is explicitly applied.
• Reordering displayed rows does not change the relation's attributes.
వివరణ:
Question 14
ప్రశ్న 14
A table has the columns Complaint_ID, Date, Category and Status. Which statement is valid for the normal tabular representation of this relation?
Select an option first. || ముందుగా ఒక సమాధానాన్ని ఎంచుకోండి.
Explanation:
• Rows of a table conform to the same defined column structure.
• Each row therefore has values corresponding to Complaint_ID, Date, Category and Status, subject to the database's applicable rules for missing or null values.
• The values can differ between rows even though the set of attributes remains the same.
• Each row therefore has values corresponding to Complaint_ID, Date, Category and Status, subject to the database's applicable rules for missing or null values.
• The values can differ between rows even though the set of attributes remains the same.
వివరణ:
Question 15
ప్రశ్న 15
In relational terminology, what is a domain associated with an attribute?
Select an option first. || ముందుగా ఒక సమాధానాన్ని ఎంచుకోండి.
Explanation:
• A domain specifies the values or conditions that are valid for an attribute.
• For example, a domain may restrict an attribute to an appropriate type or permitted range of values.
• A domain is therefore concerned with valid attribute values, not physical storage or row ordering.
• For example, a domain may restrict an attribute to an appropriate type or permitted range of values.
• A domain is therefore concerned with valid attribute values, not physical storage or row ordering.
వివరణ:
Question 16
ప్రశ్న 16
A relation has degree 5. Which conclusion follows directly from this information?
Select an option first. || ముందుగా ఒక సమాధానాన్ని ఎంచుకోండి.
Explanation:
• Degree refers to the number of attributes in a relation.
• Therefore a relation of degree 5 has five attributes, represented as five columns in its tabular form.
• Degree does not specify how many tuples or records the relation contains.
• Therefore a relation of degree 5 has five attributes, represented as five columns in its tabular form.
• Degree does not specify how many tuples or records the relation contains.
వివరణ:
Question 17
ప్రశ్న 17
Consider the following statements about relational terminology:
1. A relation is commonly represented as a table.
2. A tuple corresponds to a row.
3. An attribute corresponds to a column.
4. In formal relational terminology, the cardinality of a relation refers to its number of tuples.
Which statements are correct?
1. A relation is commonly represented as a table.
2. A tuple corresponds to a row.
3. An attribute corresponds to a column.
4. In formal relational terminology, the cardinality of a relation refers to its number of tuples.
Which statements are correct?
Select an option first. || ముందుగా ఒక సమాధానాన్ని ఎంచుకోండి.
Explanation:
• A relation is represented as a table, with tuples represented as rows and attributes represented as columns.
• In formal relational terminology, relation cardinality is the number of tuples in the relation.
• Therefore all four statements are correct.
• In formal relational terminology, relation cardinality is the number of tuples in the relation.
• Therefore all four statements are correct.
వివరణ:
Question 18
ప్రశ్న 18
A POLICE_STATION relation contains 125 rows and the eight columns Station_ID, Station_Name, District, Division, Address, Phone, Officer_Name and Category. In formal relational terminology, which pair is correct?
Select an option first. || ముందుగా ఒక సమాధానాన్ని ఎంచుకోండి.
Explanation:
• Degree is the number of attributes or columns, so the degree is 8.
• Relation cardinality is the number of tuples or rows, so the cardinality is 125.
• The two terms therefore describe different dimensions of the relation.
• Relation cardinality is the number of tuples or rows, so the cardinality is 125.
• The two terms therefore describe different dimensions of the relation.
వివరణ:
Question 19
ప్రశ్న 19
Match List I with List II:
List I
(a) Relation
(b) Tuple
(c) Attribute
(d) Degree
List II
1. Number of attributes in a relation
2. Row in the tabular representation
3. Column in the tabular representation
4. Structure commonly represented as a table
Choose the correct matching code.
List I
(a) Relation
(b) Tuple
(c) Attribute
(d) Degree
List II
1. Number of attributes in a relation
2. Row in the tabular representation
3. Column in the tabular representation
4. Structure commonly represented as a table
Choose the correct matching code.
Select an option first. || ముందుగా ఒక సమాధానాన్ని ఎంచుకోండి.
Explanation:
• A relation is commonly represented as a table, giving (a)-4.
• A tuple corresponds to a row and an attribute corresponds to a column, giving (b)-2 and (c)-3.
• Degree is the number of attributes in the relation, giving (d)-1.
• A tuple corresponds to a row and an attribute corresponds to a column, giving (b)-2 and (c)-3.
• Degree is the number of attributes in the relation, giving (d)-1.
వివరణ:
Question 20
ప్రశ్న 20
Assertion (A): In an EMPLOYEE table, one complete row can be regarded as the record for one employee.
Reason (R): The row contains values corresponding to the table's defined columns or attributes for that particular employee instance.
Choose the correct answer.
Reason (R): The row contains values corresponding to the table's defined columns or attributes for that particular employee instance.
Choose the correct answer.
Select an option first. || ముందుగా ఒక సమాధానాన్ని ఎంచుకోండి.
Explanation:
• A complete row contains the field or attribute values associated with one represented instance, such as one employee.
• For this reason, a row is commonly described as a record and formally as a tuple.
• Both statements are true, and the Reason correctly explains the Assertion.
• For this reason, a row is commonly described as a record and formally as a tuple.
• Both statements are true, and the Reason correctly explains the Assertion.
వివరణ:
Answer Key సమాధానాల పట్టిక
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Question 1 ప్రశ్న 1Answer: C. Relation సమాధానం: C.
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Question 2 ప్రశ్న 2Answer: A. Tuple సమాధానం: A.
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Question 3 ప్రశ్న 3Answer: D. Attribute సమాధానం: D.
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Question 4 ప్రశ్న 4Answer: B. Record సమాధానం: B.
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Question 5 ప్రశ్న 5Answer: B. A column representing one category of data across records సమాధానం: B.
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Question 6 ప్రశ్న 6Answer: D. 6 సమాధానం: D.
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Question 7 ప్రశ్న 7Answer: A. 250 సమాధానం: A.
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Question 8 ప్రశ్న 8Answer: C. A field or attribute value సమాధానం: C.
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Question 9 ప్రశ్న 9Answer: D. The relation's defined structure, including its name and attributes సమాధానం: D.
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Question 10 ప్రశ్న 10Answer: B. A table can describe a subject such as EMPLOYEE, while each row represents one instance such as a particular employee. సమాధానం: B.
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Question 11 ప్రశ్న 11Answer: C. The number of rows increases, while the existing column structure can remain unchanged. సమాధానం: C.
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Question 12 ప్రశ్న 12Answer: A. A relation is a set of tuples, so two completely identical tuples are not distinct members of the same relation. సమాధానం: A.
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Question 13 ప్రశ్న 13Answer: A. The relational model does not assign inherent meaning to the physical order of tuples in a relation. సమాధానం: A.
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Question 14 ప్రశ్న 14Answer: C. Each row follows the same set of four columns, although the stored values can differ from row to row. సమాధానం: C.
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Question 15 ప్రశ్న 15Answer: B. The set or conditions of permissible values for that attribute సమాధానం: B.
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Question 16 ప్రశ్న 16Answer: D. The relation has five attributes or columns in its relational structure. సమాధానం: D.
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Question 17 ప్రశ్న 17Answer: C. 1, 2, 3 and 4 సమాధానం: C.
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Question 18 ప్రశ్న 18Answer: A. Degree = 8; Cardinality = 125 సమాధానం: A.
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Question 19 ప్రశ్న 19Answer: D. (a)-4, (b)-2, (c)-3, (d)-1 సమాధానం: D.
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Question 20 ప్రశ్న 20Answer: B. Both Assertion and Reason are true, and Reason is the correct explanation of Assertion. సమాధానం: B.