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The term "ODBC" stands for_____- a)Oral database connectivity
- b)Oracle database connectivity
- c)Open database connectivity
- d)Object database connectivity
Correct answer is option 'C'. Can you explain this answer?
The term "ODBC" stands for_____
a)
Oral database connectivity
b)
Oracle database connectivity
c)
Open database connectivity
d)
Object database connectivity
|
Aniket Banerjee answered |
"term" can have different meanings depending on the context in which it is used. Here are a few possible interpretations:
1. In linguistics, a term refers to a word or phrase that represents a specific concept or object.
2. In mathematics, a term is a component of an algebraic expression or equation that can be added or subtracted.
3. In education, a term refers to a specific period of time during which academic instruction takes place, such as a semester or a quarter.
4. In law, a term refers to the conditions or provisions of a contract or agreement.
5. In business, a term can refer to the length of time for which a loan or financial agreement is in effect.
These are just a few examples, and the meaning of the term "term" can vary depending on the specific field or context in which it is used.
1. In linguistics, a term refers to a word or phrase that represents a specific concept or object.
2. In mathematics, a term is a component of an algebraic expression or equation that can be added or subtracted.
3. In education, a term refers to a specific period of time during which academic instruction takes place, such as a semester or a quarter.
4. In law, a term refers to the conditions or provisions of a contract or agreement.
5. In business, a term can refer to the length of time for which a loan or financial agreement is in effect.
These are just a few examples, and the meaning of the term "term" can vary depending on the specific field or context in which it is used.
Which of the following levels is considered as the level closed to the end-users?- a)Internal Level
- b)External Level
- c)Conceptual Level
- d)Physical Level
Correct answer is option 'B'. Can you explain this answer?
Which of the following levels is considered as the level closed to the end-users?
a)
Internal Level
b)
External Level
c)
Conceptual Level
d)
Physical Level
|
Hansa Sharma answered |
The database's external level is the one and only level that is considered the closest level to the end-users. So the correct answer will be the B.
Which one of the following refers to the "data about data"?- a)Directory
- b)Sub Data
- c)Warehouse
- d)Meta Data
Correct answer is option 'D'. Can you explain this answer?
Which one of the following refers to the "data about data"?
a)
Directory
b)
Sub Data
c)
Warehouse
d)
Meta Data
|
Kavya Khanna answered |
Sorry, but I need more information to answer your question. Can you please provide the options you are referring to?
Which of the following is used in the application programs to request data from the database management system?- a)Data Manipulation language
- b)Data Definition Language
- c)Data Control Language
- d)All of the above
Correct answer is option 'A'. Can you explain this answer?
Which of the following is used in the application programs to request data from the database management system?
a)
Data Manipulation language
b)
Data Definition Language
c)
Data Control Language
d)
All of the above
|
|
Ravi Sharma answered |
To fetch data from the database management system, generally, the "select" statement is used. Therefore, the Data Manipulation Language is used in the application programs while requesting the data from the database management system.
Ready the Query carefully:SELECT emp_name
FROM department
WHERE dept_name LIKE ' _____ Computer Science'; In the above-given Query, which of the following can be placed in the Query's blank portion to select the "dept_name" that also contains Computer Science as its ending string?- a)&
- b)_
- c)%
- d)$
Correct answer is option 'C'. Can you explain this answer?
Ready the Query carefully:
SELECT emp_name
FROM department
WHERE dept_name LIKE ' _____ Computer Science';
FROM department
WHERE dept_name LIKE ' _____ Computer Science';
In the above-given Query, which of the following can be placed in the Query's blank portion to select the "dept_name" that also contains Computer Science as its ending string?
a)
&
b)
_
c)
%
d)
$
|
Devansh Choudhary answered |
Employee names from the "Computer Science" department?
A. '%'
B. '_'
C. '%Computer Science%'
D. 'Computer Science'
A. '%'
B. '_'
C. '%Computer Science%'
D. 'Computer Science'
Which of the following is generally used for performing tasks like creating the structure of the relations, deleting relation?- a)DML(Data Manipulation Language)
- b)Query
- c)Relational Schema
- d)DDL(Data Definition Language)
Correct answer is option 'D'. Can you explain this answer?
Which of the following is generally used for performing tasks like creating the structure of the relations, deleting relation?
a)
DML(Data Manipulation Language)
b)
Query
c)
Relational Schema
d)
DDL(Data Definition Language)
|
Gaurav Kumar answered |
The term "DDL" stands for Data Definition Language, used to perform all other essential tasks such as deleting relation and related schemas in defining the structure relation.
Which one of the following command is used to delete the existing row in a table?- a)Delete
- b)Update
- c)Insert
- d)None of the above
Correct answer is option 'A'. Can you explain this answer?
Which one of the following command is used to delete the existing row in a table?
a)
Delete
b)
Update
c)
Insert
d)
None of the above
|
|
Hansa Sharma answered |
To delete an existing row in a table the generally, the "delete" command is used. The "delete" command is one of the commands that belong to the Data manipulation language.
The term "Data" refers to:- a)The electronic representation of the information( or data)
- b)Basic information
- c)Row Facts and figures
- d)Both A and C
Correct answer is option 'C'. Can you explain this answer?
The term "Data" refers to:
a)
The electronic representation of the information( or data)
b)
Basic information
c)
Row Facts and figures
d)
Both A and C
|
Ankit Shah answered |
"term" can have multiple meanings depending on the context in which it is used. Here are a few potential meanings:
1. A word or phrase that is used to describe or identify something. For example, the term "apple" refers to a type of fruit.
2. A set period of time. For example, the term "semester" refers to a specific period of time in an academic year.
3. A condition or requirement. For example, someone may agree to a contract "on the terms and conditions" stated.
4. A concept or idea. For example, the term "democracy" refers to a form of government where power is held by the people.
5. A specific meaning or definition. For example, the term "capitalism" has various interpretations and definitions.
It is important to consider the context in which the term is used to determine its specific meaning.
1. A word or phrase that is used to describe or identify something. For example, the term "apple" refers to a type of fruit.
2. A set period of time. For example, the term "semester" refers to a specific period of time in an academic year.
3. A condition or requirement. For example, someone may agree to a contract "on the terms and conditions" stated.
4. A concept or idea. For example, the term "democracy" refers to a form of government where power is held by the people.
5. A specific meaning or definition. For example, the term "capitalism" has various interpretations and definitions.
It is important to consider the context in which the term is used to determine its specific meaning.
The term "NTFS" refers to which one of the following?- a)New Technology File System
- b)New Tree File System
- c)New Table type File System
- d)Both A and C
Correct answer is option 'A'. Can you explain this answer?
The term "NTFS" refers to which one of the following?
a)
New Technology File System
b)
New Tree File System
c)
New Table type File System
d)
Both A and C
|
|
Gaurav Kumar answered |
In the old operating systems, the file structure used to store and manage files is called the FAT 32 ( or File Allocation Table). Later, when the technology evolves with time, a new type of file system is introduced, known as the New Technology File System. It overcomes all the drawbacks, issues that exist in FAT file architecture and has many other new features such as it is fast, it can handle files whose size is even greater than 4 GB.
Which one of the following refers to the copies of the same data (or information) occupying the memory space at multiple places.- a)Data Repository
- b)Data Inconsistency
- c)Data Mining
- d)Data Redundancy
Correct answer is option 'D'. Can you explain this answer?
Which one of the following refers to the copies of the same data (or information) occupying the memory space at multiple places.
a)
Data Repository
b)
Data Inconsistency
c)
Data Mining
d)
Data Redundancy
|
|
Hansa Sharma answered |
The data redundancy generally occurs whenever more than one copy of the exact same data exists in several different places. Sometimes it may cause data inconsistency, which can result in an unreliable source of data or information that is not good for anyone.
Rows of a relation are known as the _______.
- a)Degree
- b)All of the above
- c)Entity
- d)Tuples
Correct answer is option 'D'. Can you explain this answer?
Rows of a relation are known as the _______.
a)
Degree
b)
All of the above
c)
Entity
d)
Tuples
|
Sarthak Banerjee answered |
Rows of a relation are known as the Tuples.
Rows of a relation in a database are known as tuples. A tuple is a collection of attributes or fields that represents a single record in a table. Each tuple contains a unique combination of attribute values, which represents a specific instance or entity in the database.
What is a relation?
In the context of databases, a relation refers to a table that consists of rows and columns. A relation represents a specific entity or concept in the real world, and each row in the relation represents a unique instance or occurrence of that entity. For example, a relation can represent a customer table, where each row represents a unique customer.
What are tuples?
Tuples are the rows of a relation. Each tuple contains a set of attribute values that correspond to the columns or attributes of the relation. For example, in a customer table, each tuple represents a specific customer and contains attribute values such as customer ID, name, address, and phone number.
What are attributes?
Attributes are the columns or fields of a relation. Each attribute represents a specific characteristic or property of the entity being represented by the relation. In the customer table example, attributes could include customer ID, name, address, and phone number.
Why are tuples important?
Tuples are important because they allow us to represent and manipulate data in a structured and organized manner. By organizing data into tuples, we can easily retrieve, update, and analyze specific instances or entities within a database. Tuples also provide a way to establish relationships between different tables or relations in a database.
Summary:
In a database, rows of a relation are known as tuples. Tuples represent unique instances or occurrences of an entity and contain a set of attribute values that correspond to the columns or attributes of the relation. By organizing data into tuples, we can easily manage and manipulate data within a database.
Rows of a relation in a database are known as tuples. A tuple is a collection of attributes or fields that represents a single record in a table. Each tuple contains a unique combination of attribute values, which represents a specific instance or entity in the database.
What is a relation?
In the context of databases, a relation refers to a table that consists of rows and columns. A relation represents a specific entity or concept in the real world, and each row in the relation represents a unique instance or occurrence of that entity. For example, a relation can represent a customer table, where each row represents a unique customer.
What are tuples?
Tuples are the rows of a relation. Each tuple contains a set of attribute values that correspond to the columns or attributes of the relation. For example, in a customer table, each tuple represents a specific customer and contains attribute values such as customer ID, name, address, and phone number.
What are attributes?
Attributes are the columns or fields of a relation. Each attribute represents a specific characteristic or property of the entity being represented by the relation. In the customer table example, attributes could include customer ID, name, address, and phone number.
Why are tuples important?
Tuples are important because they allow us to represent and manipulate data in a structured and organized manner. By organizing data into tuples, we can easily retrieve, update, and analyze specific instances or entities within a database. Tuples also provide a way to establish relationships between different tables or relations in a database.
Summary:
In a database, rows of a relation are known as tuples. Tuples represent unique instances or occurrences of an entity and contain a set of attribute values that correspond to the columns or attributes of the relation. By organizing data into tuples, we can easily manage and manipulate data within a database.
Which one of the following given statements possibly contains the error?- a)select * from emp where empid = 10003;
- b)select empid from emp where empid = 10006;
- c)select empid from emp;
- d)select empid where empid = 1009 and Lastname = 'GELLER';
Correct answer is option 'D'. Can you explain this answer?
Which one of the following given statements possibly contains the error?
a)
select * from emp where empid = 10003;
b)
select empid from emp where empid = 10006;
c)
select empid from emp;
d)
select empid where empid = 1009 and Lastname = 'GELLER';
|
|
Hansa Sharma answered |
The Query given in option D does not contain the "from" clause, which specifies the relation from which the values have to be selected or fetched. Therefore the correct answer is D.
The term "Data independence" refers to____- a)Data is defined separately and not included in the programs
- b)Programs are not dependent on the logical attributes of the data
- c)Programs are not dependent on the physical attributes of the data
- d)Both B & C
Correct answer is option 'D'. Can you explain this answer?
The term "Data independence" refers to____
a)
Data is defined separately and not included in the programs
b)
Programs are not dependent on the logical attributes of the data
c)
Programs are not dependent on the physical attributes of the data
d)
Both B & C
|
|
Gaurav Kumar answered |
The term "Data independence" refers that the program should not be dependent on either the logical attributes of data or physical attributes of data.
Which of the following can be considered as the maximum size that is supported by FAT?- a)8GB
- b)4GB
- c)4TB
- d)None of the above
Correct answer is option 'B'. Can you explain this answer?
Which of the following can be considered as the maximum size that is supported by FAT?
a)
8GB
b)
4GB
c)
4TB
d)
None of the above
|
|
Anaya Patel answered |
The files with a size of less than 4 GB or equal to 4GB are easily supported by the FAT. All files with a size greater than the maximum size (or is 4Gb) are not supported by the FAT.
What is the relation calculus?- a)It is a kind of procedural language
- b)It is a non-procedural language
- c)It is a high-level language
- d)It is Data Definition language
Correct answer is option 'B'. Can you explain this answer?
What is the relation calculus?
a)
It is a kind of procedural language
b)
It is a non-procedural language
c)
It is a high-level language
d)
It is Data Definition language
|
|
Anaya Patel answered |
In database management systems, relation calculus is a type of non-procedural query language that describes what data needs to be retrieved. However, it does not explain how to retrieve the data.
In which one of the following, the multiple lower entities are grouped (or combined) together to form a single higher-level entity?- a)Specialization
- b)Generalization
- c)Aggregation
- d)None of the above
Correct answer is option 'B'. Can you explain this answer?
In which one of the following, the multiple lower entities are grouped (or combined) together to form a single higher-level entity?
a)
Specialization
b)
Generalization
c)
Aggregation
d)
None of the above
|
|
Harshitha Basu answered |
Generalization
Generalization is the process of combining multiple lower entities to form a single higher-level entity. It is a concept used in various fields, including computer science, data modeling, and even in the study of human knowledge and understanding.
Explanation:
Generalization involves creating a higher-level entity that represents a commonality or abstraction of multiple lower-level entities. It is typically used when there are similarities or shared characteristics among the lower entities that can be generalized into a single concept.
Example:
To better understand generalization, let's consider an example in the field of computer science. Suppose we have a class hierarchy for vehicles, where we have specific classes for cars, motorcycles, and bicycles. Each of these lower-level entities has its own unique attributes and behaviors.
However, we can also identify common attributes and behaviors that are shared among all vehicles. For example, all vehicles have a color, a number of wheels, and a maximum speed. Instead of duplicating these attributes and behaviors in each specific class, we can create a higher-level entity called "Vehicle" and generalize these common characteristics.
By generalizing the common attributes and behaviors into the "Vehicle" class, we can reduce redundancy and make the class hierarchy more organized and efficient. This also allows us to define common methods or functions that can be used by all types of vehicles.
Advantages of Generalization:
- Reduces redundancy: Generalization helps to eliminate the repetition of common attributes and behaviors among lower entities, leading to more efficient and maintainable code or data models.
- Enhances organization: By grouping similar entities together, generalization improves the organization and structure of a system or model.
- Enables abstraction: Generalization allows us to abstract the common characteristics of lower entities, making it easier to understand and work with complex systems.
In conclusion, generalization is the process of combining multiple lower entities into a single higher-level entity. It helps to eliminate redundancy, improve organization, and enable abstraction in various fields.
Generalization is the process of combining multiple lower entities to form a single higher-level entity. It is a concept used in various fields, including computer science, data modeling, and even in the study of human knowledge and understanding.
Explanation:
Generalization involves creating a higher-level entity that represents a commonality or abstraction of multiple lower-level entities. It is typically used when there are similarities or shared characteristics among the lower entities that can be generalized into a single concept.
Example:
To better understand generalization, let's consider an example in the field of computer science. Suppose we have a class hierarchy for vehicles, where we have specific classes for cars, motorcycles, and bicycles. Each of these lower-level entities has its own unique attributes and behaviors.
However, we can also identify common attributes and behaviors that are shared among all vehicles. For example, all vehicles have a color, a number of wheels, and a maximum speed. Instead of duplicating these attributes and behaviors in each specific class, we can create a higher-level entity called "Vehicle" and generalize these common characteristics.
By generalizing the common attributes and behaviors into the "Vehicle" class, we can reduce redundancy and make the class hierarchy more organized and efficient. This also allows us to define common methods or functions that can be used by all types of vehicles.
Advantages of Generalization:
- Reduces redundancy: Generalization helps to eliminate the repetition of common attributes and behaviors among lower entities, leading to more efficient and maintainable code or data models.
- Enhances organization: By grouping similar entities together, generalization improves the organization and structure of a system or model.
- Enables abstraction: Generalization allows us to abstract the common characteristics of lower entities, making it easier to understand and work with complex systems.
In conclusion, generalization is the process of combining multiple lower entities into a single higher-level entity. It helps to eliminate redundancy, improve organization, and enable abstraction in various fields.
Which of the following can be considered as the maximum size that is supported by NTFS?- a)4GB
- b)16TB
- c)64TB
- d)8TB
Correct answer is option 'A'. Can you explain this answer?
Which of the following can be considered as the maximum size that is supported by NTFS?
a)
4GB
b)
16TB
c)
64TB
d)
8TB
|
|
Hansa Sharma answered |
The New Technology File System was introduced in 1993 for the very first time as a part of new Windows operating systems (Windows NT 3.1).
You may be surprised to know that windows are still using it because of its fast speed and can support files whose size is up to 16TB (16 terabytes), which is much more than that file size supported by the old system.
You may be surprised to know that windows are still using it because of its fast speed and can support files whose size is up to 16TB (16 terabytes), which is much more than that file size supported by the old system.
Which of the following can be used to extract or filter the data & information from the data warehouse?- a)Data redundancy
- b)Data recovery tool
- c)Data mining
- d)Both B and C
Correct answer is option 'C'. Can you explain this answer?
Which of the following can be used to extract or filter the data & information from the data warehouse?
a)
Data redundancy
b)
Data recovery tool
c)
Data mining
d)
Both B and C
|
|
Ravi Sharma answered |
The tools used to obtain meaningful information or Data from the large collection of data (or from the Data Warehouses) are known as the Data mining tools. Through data mining, one can easily filter the useful information or data from the massive collection of the data. Therefore the correct answer is Data Mining.
Which of the following keys is generally used to represents the relationships between the tables?- a)Primary key
- b)Foreign key
- c)Secondary key
- d)None of the above
Correct answer is option 'B'. Can you explain this answer?
Which of the following keys is generally used to represents the relationships between the tables?
a)
Primary key
b)
Foreign key
c)
Secondary key
d)
None of the above
|
Sanskriti Deshpande answered |
Foreign key
A foreign key is generally used to represent the relationships between tables in a database. Let's understand this concept in detail:
Tables in a database:
- In a database, data is stored in tables that are organized into rows and columns. Each table represents a specific entity or concept, and each row in the table represents a specific instance or record of that entity.
- For example, in a database for a school, you might have separate tables for students, teachers, and classes. Each table would contain relevant data about the respective entities.
Relationships between tables:
- In a relational database, tables are often related to each other through common attributes or fields.
- For example, in the school database, the students table and the classes table might be related by a common attribute such as the class ID.
- These relationships allow us to retrieve and manipulate data across multiple tables, enabling the database to represent complex real-world scenarios.
Foreign key:
- A foreign key is a field or combination of fields in one table that refers to the primary key in another table.
- It establishes a link between two tables by enforcing referential integrity, which ensures that the values in the foreign key field(s) correspond to an existing value in the referenced table's primary key.
- In the school database example, the classes table might have a foreign key field called "student_id" that references the primary key field "id" in the students table.
- This foreign key relationship would indicate that each class entry is associated with a specific student entry.
Representing relationships:
- By using foreign keys, we can represent various types of relationships between tables, such as one-to-one, one-to-many, and many-to-many.
- For example, a one-to-many relationship can be represented by having the primary key of the "one" table as a foreign key in the "many" table.
- This allows us to establish connections and retrieve related data efficiently when querying the database.
Conclusion:
In summary, the foreign key is generally used to represent the relationships between tables in a database. It establishes connections between tables by referencing the primary key of one table in another table, enabling efficient retrieval and manipulation of related data.
A foreign key is generally used to represent the relationships between tables in a database. Let's understand this concept in detail:
Tables in a database:
- In a database, data is stored in tables that are organized into rows and columns. Each table represents a specific entity or concept, and each row in the table represents a specific instance or record of that entity.
- For example, in a database for a school, you might have separate tables for students, teachers, and classes. Each table would contain relevant data about the respective entities.
Relationships between tables:
- In a relational database, tables are often related to each other through common attributes or fields.
- For example, in the school database, the students table and the classes table might be related by a common attribute such as the class ID.
- These relationships allow us to retrieve and manipulate data across multiple tables, enabling the database to represent complex real-world scenarios.
Foreign key:
- A foreign key is a field or combination of fields in one table that refers to the primary key in another table.
- It establishes a link between two tables by enforcing referential integrity, which ensures that the values in the foreign key field(s) correspond to an existing value in the referenced table's primary key.
- In the school database example, the classes table might have a foreign key field called "student_id" that references the primary key field "id" in the students table.
- This foreign key relationship would indicate that each class entry is associated with a specific student entry.
Representing relationships:
- By using foreign keys, we can represent various types of relationships between tables, such as one-to-one, one-to-many, and many-to-many.
- For example, a one-to-many relationship can be represented by having the primary key of the "one" table as a foreign key in the "many" table.
- This allows us to establish connections and retrieve related data efficiently when querying the database.
Conclusion:
In summary, the foreign key is generally used to represent the relationships between tables in a database. It establishes connections between tables by referencing the primary key of one table in another table, enabling efficient retrieval and manipulation of related data.
What do you mean by one to many relationships?- a)One class may have many teachers
- b)One teacher can have many classes
- c)Many classes may have many teachers
- d)Many teachers may have many classes
Correct answer is option 'B'. Can you explain this answer?
What do you mean by one to many relationships?
a)
One class may have many teachers
b)
One teacher can have many classes
c)
Many classes may have many teachers
d)
Many teachers may have many classes
|
|
Gaurav Kumar answered |
We can understand the "one to many" relationship as a teacher who may have more than one class to attend.
Which of the following refers to the number of attributes in a relation?- a)Degree
- b)Row
- c)Column
- d)All of the above
Correct answer is option 'A'. Can you explain this answer?
Which of the following refers to the number of attributes in a relation?
a)
Degree
b)
Row
c)
Column
d)
All of the above
|
Aryan Chavan answered |
The Number of Attributes in a Relation
Explanation:
In the context of relational databases, a relation refers to a table that consists of rows and columns. Each row represents a record or a tuple, and each column represents an attribute or a field. The number of attributes in a relation refers to the total number of columns present in the table.
Definition of Degree:
Degree is a term used in database management systems to describe the number of attributes or columns in a relation. It represents the total number of fields or properties that a relation has. In other words, the degree of a relation indicates the number of columns or attributes present in the table.
Relation to the Given Options:
Among the given options, the correct answer is option 'A' - Degree. The degree of a relation refers to the number of attributes in that relation. Therefore, option 'A' is the most appropriate choice.
Other Options:
- Option 'B' - Row: This refers to a single record or tuple in a relation. The number of rows does not indicate the number of attributes.
- Option 'C' - Column: This refers to an attribute or field in a relation. While it is related to the number of attributes, it does not specifically represent the total count of attributes.
- Option 'D' - All of the above: This option is incorrect as it includes options 'B' and 'C', which do not accurately represent the number of attributes in a relation.
Conclusion:
The correct answer to the question is option 'A' - Degree. It specifically represents the number of attributes or columns in a relation, accurately reflecting the total count of fields or properties in the table.
Explanation:
In the context of relational databases, a relation refers to a table that consists of rows and columns. Each row represents a record or a tuple, and each column represents an attribute or a field. The number of attributes in a relation refers to the total number of columns present in the table.
Definition of Degree:
Degree is a term used in database management systems to describe the number of attributes or columns in a relation. It represents the total number of fields or properties that a relation has. In other words, the degree of a relation indicates the number of columns or attributes present in the table.
Relation to the Given Options:
Among the given options, the correct answer is option 'A' - Degree. The degree of a relation refers to the number of attributes in that relation. Therefore, option 'A' is the most appropriate choice.
Other Options:
- Option 'B' - Row: This refers to a single record or tuple in a relation. The number of rows does not indicate the number of attributes.
- Option 'C' - Column: This refers to an attribute or field in a relation. While it is related to the number of attributes, it does not specifically represent the total count of attributes.
- Option 'D' - All of the above: This option is incorrect as it includes options 'B' and 'C', which do not accurately represent the number of attributes in a relation.
Conclusion:
The correct answer to the question is option 'A' - Degree. It specifically represents the number of attributes or columns in a relation, accurately reflecting the total count of fields or properties in the table.
A huge collection of the information or data accumulated form several different sources is known as ________:- a)Data Management
- b)Data Mining
- c)Data Warehouse
- d)Both B and C
Correct answer is option 'C'. Can you explain this answer?
A huge collection of the information or data accumulated form several different sources is known as ________:
a)
Data Management
b)
Data Mining
c)
Data Warehouse
d)
Both B and C
|
|
Preethi Sen answered |
Data Warehouse:
- A data warehouse is a huge collection of data that is accumulated from several different sources. It is a central repository of integrated data that allows organizations to store, manage, and analyze large amounts of data from various sources.
- The main purpose of a data warehouse is to provide a consolidated view of data that can be used for reporting, analysis, and decision-making.
- Data warehouses are designed to support the efficient retrieval and analysis of data, making it easier for organizations to gain insights and make informed decisions.
- Data warehouses typically contain historical data, which is stored in a structured and organized manner. This allows users to analyze trends and patterns over time.
- The data in a data warehouse is often cleaned, transformed, and integrated to ensure consistency and accuracy. This process, known as ETL (Extract, Transform, Load), involves extracting data from various sources, transforming it into a common format, and loading it into the data warehouse.
- Data warehouses are typically used by businesses and organizations that have large amounts of data and need to analyze it for various purposes, such as business intelligence, reporting, and decision support.
- Data warehouses are different from operational databases, which are designed for transactional processing and day-to-day operations. Data warehouses are optimized for analytical processing and provide a separate environment for data analysis.
- By consolidating data from different sources into a single data warehouse, organizations can eliminate data silos and gain a holistic view of their data. This enables them to make better-informed decisions and improve overall business performance.
- A data warehouse is a huge collection of data that is accumulated from several different sources. It is a central repository of integrated data that allows organizations to store, manage, and analyze large amounts of data from various sources.
- The main purpose of a data warehouse is to provide a consolidated view of data that can be used for reporting, analysis, and decision-making.
- Data warehouses are designed to support the efficient retrieval and analysis of data, making it easier for organizations to gain insights and make informed decisions.
- Data warehouses typically contain historical data, which is stored in a structured and organized manner. This allows users to analyze trends and patterns over time.
- The data in a data warehouse is often cleaned, transformed, and integrated to ensure consistency and accuracy. This process, known as ETL (Extract, Transform, Load), involves extracting data from various sources, transforming it into a common format, and loading it into the data warehouse.
- Data warehouses are typically used by businesses and organizations that have large amounts of data and need to analyze it for various purposes, such as business intelligence, reporting, and decision support.
- Data warehouses are different from operational databases, which are designed for transactional processing and day-to-day operations. Data warehouses are optimized for analytical processing and provide a separate environment for data analysis.
- By consolidating data from different sources into a single data warehouse, organizations can eliminate data silos and gain a holistic view of their data. This enables them to make better-informed decisions and improve overall business performance.
Which one of the following commands is used for removing (or deleting) a relation forms the SQL database?- a)Delete
- b)Drop
- c)Remove
- d)All of the above
Correct answer is option 'B'. Can you explain this answer?
Which one of the following commands is used for removing (or deleting) a relation forms the SQL database?
a)
Delete
b)
Drop
c)
Remove
d)
All of the above
|
|
Sanskriti Deshpande answered |
Explanation:
In SQL, the command used for removing or deleting a relation or table from the database is the DROP command. This command permanently removes the specified relation from the database.
Details:
The DROP command is used to delete an entire relation or table along with all its data and associated objects such as indexes, constraints, triggers, etc. It is a powerful command that should be used with caution as it cannot be undone and the data will be lost permanently.
Syntax:
The syntax of the DROP command is as follows:
```
DROP TABLE table_name;
```
Here, `table_name` refers to the name of the relation or table that needs to be dropped.
Example:
Suppose we have a relation named "employees" in our database, and we want to delete it. We can use the DROP command as follows:
```
DROP TABLE employees;
```
This command will remove the "employees" relation from the database, along with all its data and associated objects.
Alternative commands:
- The DELETE command is used to delete specific rows or records from a relation, but it does not remove the entire relation itself. It is used to remove specific data from a table based on certain conditions.
- The REMOVE command is not a standard SQL command for removing relations. It may be a command specific to certain database management systems or programming languages.
- Therefore, the correct answer is option B) Drop, as it is the standard SQL command used for removing or deleting a relation or table from the database.
In SQL, the command used for removing or deleting a relation or table from the database is the DROP command. This command permanently removes the specified relation from the database.
Details:
The DROP command is used to delete an entire relation or table along with all its data and associated objects such as indexes, constraints, triggers, etc. It is a powerful command that should be used with caution as it cannot be undone and the data will be lost permanently.
Syntax:
The syntax of the DROP command is as follows:
```
DROP TABLE table_name;
```
Here, `table_name` refers to the name of the relation or table that needs to be dropped.
Example:
Suppose we have a relation named "employees" in our database, and we want to delete it. We can use the DROP command as follows:
```
DROP TABLE employees;
```
This command will remove the "employees" relation from the database, along with all its data and associated objects.
Alternative commands:
- The DELETE command is used to delete specific rows or records from a relation, but it does not remove the entire relation itself. It is used to remove specific data from a table based on certain conditions.
- The REMOVE command is not a standard SQL command for removing relations. It may be a command specific to certain database management systems or programming languages.
- Therefore, the correct answer is option B) Drop, as it is the standard SQL command used for removing or deleting a relation or table from the database.
A Database Management System is a type of _________software.- a)It is a type of system software
- b)It is a kind of application software
- c)It is a kind of general software
- d)Both A and C
Correct answer is option 'A'. Can you explain this answer?
A Database Management System is a type of _________software.
a)
It is a type of system software
b)
It is a kind of application software
c)
It is a kind of general software
d)
Both A and C
|
Aditya Choudhary answered |
A Database Management System (DBMS) is a type of system software.
The term "TCL" stands for_____.- a)Ternary Control Language
- b)Transmission Control Language
- c)Transaction Central Language
- d)Transaction Control Language
Correct answer is option 'D'. Can you explain this answer?
The term "TCL" stands for_____.
a)
Ternary Control Language
b)
Transmission Control Language
c)
Transaction Central Language
d)
Transaction Control Language
|
Priyanka Chavan answered |
"term" can have several different meanings depending on the context in which it is used. Here are a few possible interpretations:
1. In linguistics, a term refers to a word or phrase that has a specific meaning within a particular field or domain. For example, in computer science, the term "algorithm" refers to a step-by-step procedure for solving a problem.
2. In mathematics, a term is a single element or component of an expression or equation. For example, in the expression 3x^2 + 5x - 2, each of the numbers and variables (3x^2, 5x, and -2) is a term.
3. In education, a term refers to a specific period of time during which classes are taught and academic activities take place. For example, a school year may be divided into multiple terms, such as fall, winter, and spring terms.
4. In legal contexts, a term refers to a condition or provision that is included in a contract or agreement. These terms define the rights and obligations of the parties involved.
Overall, the meaning of the term "term" depends on the context in which it is used.
1. In linguistics, a term refers to a word or phrase that has a specific meaning within a particular field or domain. For example, in computer science, the term "algorithm" refers to a step-by-step procedure for solving a problem.
2. In mathematics, a term is a single element or component of an expression or equation. For example, in the expression 3x^2 + 5x - 2, each of the numbers and variables (3x^2, 5x, and -2) is a term.
3. In education, a term refers to a specific period of time during which classes are taught and academic activities take place. For example, a school year may be divided into multiple terms, such as fall, winter, and spring terms.
4. In legal contexts, a term refers to a condition or provision that is included in a contract or agreement. These terms define the rights and obligations of the parties involved.
Overall, the meaning of the term "term" depends on the context in which it is used.
Which of the following refers collection of the information stored in a database at a specific time?- a)Independence
- b)Instance of the database
- c)Schema
- d)Data domain
Correct answer is option 'B'. Can you explain this answer?
Which of the following refers collection of the information stored in a database at a specific time?
a)
Independence
b)
Instance of the database
c)
Schema
d)
Data domain
|
|
Isha Kaur answered |
Instance of the database
The term "instance of the database" refers to a collection of the information stored in a database at a specific point in time. This snapshot of the data represents how the database looked at that particular moment. Let's break down this concept further:
Definition
An instance of a database is a specific representation of the data within the database at a given time. It captures the current state of the information stored in the database, including the values of the various fields and records.
Importance
Having an instance of the database is crucial for various reasons, such as data analysis, reporting, and ensuring data integrity. It allows users to work with a consistent set of data for specific tasks or analysis.
Usage
Database administrators often create instances of the database for backup purposes, to track changes over time, or to compare different versions of the data. This practice helps in understanding how the data evolves and ensuring that the right information is available when needed.
Conclusion
In summary, an instance of the database represents a snapshot of the data stored in a database at a particular time. It is a valuable tool for data management, analysis, and ensuring the accuracy and consistency of information within the database.
In general, a file is basically a collection of all related______.- a)Rows & Columns
- b)Fields
- c)Database
- d)Records
Correct answer is option 'D'. Can you explain this answer?
In general, a file is basically a collection of all related______.
a)
Rows & Columns
b)
Fields
c)
Database
d)
Records
|
|
Hansa Sharma answered |
Whenever we have some related data, information or records, we collect all those related data (or records), put them together, store them in one place, and give that collection a name that is known as a file.
In the following Query, which of the following can be placed in the Query's blank portion to display the salary from highest to lowest amount, and sorting the employs name alphabetically?SELECT *
FROM instructor
ORDER BY salary ____, name ___; - a)Ascending, Descending
- b)Asc, Desc
- c)Desc, Asc
- d)All of the above
Correct answer is option 'C'. Can you explain this answer?
In the following Query, which of the following can be placed in the Query's blank portion to display the salary from highest to lowest amount, and sorting the employs name alphabetically?
SELECT *
FROM instructor
ORDER BY salary ____, name ___;
FROM instructor
ORDER BY salary ____, name ___;
a)
Ascending, Descending
b)
Asc, Desc
c)
Desc, Asc
d)
All of the above
|
|
Kavya Khanna answered |
Explanation:
To display the salary from highest to lowest amount and sort the employees' names alphabetically, we need to use the SQL ORDER BY clause. The ORDER BY clause is used to sort the result set based on one or more columns.
Query:
SELECT * FROM instructor ORDER BY salary _____, name _____;
Options:
a) Ascending, Descending
b) Asc, Desc
c) Desc, Asc
d) All of the above
Analysis of options:
a) Ascending, Descending: This option specifies sorting the columns in ascending order for the first column and descending order for the second column.
b) Asc, Desc: This option specifies sorting the columns in ascending order for the first column and descending order for the second column.
c) Desc, Asc: This option specifies sorting the columns in descending order for the first column and ascending order for the second column.
d) All of the above: This option includes both a) and b) options which specify sorting in both ascending and descending order for different columns.
Answer:
The correct answer is option c) Desc, Asc.
Reasoning:
Since we want to display the salary from the highest amount to the lowest amount, we need to sort the "salary" column in descending order. This can be achieved by using "DESC" (short for descending) in the ORDER BY clause for the "salary" column.
Additionally, we also want to sort the employees' names alphabetically. To achieve this, we need to sort the "name" column in ascending order. This can be achieved by using "ASC" (short for ascending) in the ORDER BY clause for the "name" column.
Therefore, the correct ORDER BY clause to achieve the desired result is:
ORDER BY salary DESC, name ASC.
This will display the records in the following order:
1. The records will be sorted based on the salary column in descending order (highest to lowest).
2. If there are multiple records with the same salary, those records will be further sorted based on the name column in ascending order (A-Z).
To display the salary from highest to lowest amount and sort the employees' names alphabetically, we need to use the SQL ORDER BY clause. The ORDER BY clause is used to sort the result set based on one or more columns.
Query:
SELECT * FROM instructor ORDER BY salary _____, name _____;
Options:
a) Ascending, Descending
b) Asc, Desc
c) Desc, Asc
d) All of the above
Analysis of options:
a) Ascending, Descending: This option specifies sorting the columns in ascending order for the first column and descending order for the second column.
b) Asc, Desc: This option specifies sorting the columns in ascending order for the first column and descending order for the second column.
c) Desc, Asc: This option specifies sorting the columns in descending order for the first column and ascending order for the second column.
d) All of the above: This option includes both a) and b) options which specify sorting in both ascending and descending order for different columns.
Answer:
The correct answer is option c) Desc, Asc.
Reasoning:
Since we want to display the salary from the highest amount to the lowest amount, we need to sort the "salary" column in descending order. This can be achieved by using "DESC" (short for descending) in the ORDER BY clause for the "salary" column.
Additionally, we also want to sort the employees' names alphabetically. To achieve this, we need to sort the "name" column in ascending order. This can be achieved by using "ASC" (short for ascending) in the ORDER BY clause for the "name" column.
Therefore, the correct ORDER BY clause to achieve the desired result is:
ORDER BY salary DESC, name ASC.
This will display the records in the following order:
1. The records will be sorted based on the salary column in descending order (highest to lowest).
2. If there are multiple records with the same salary, those records will be further sorted based on the name column in ascending order (A-Z).
In a relation database, every tuples divided into the fields are known as the______.- a)Queries
- b)Domains
- c)Relations
- d)All of the above
Correct answer is option 'B'. Can you explain this answer?
In a relation database, every tuples divided into the fields are known as the______.
a)
Queries
b)
Domains
c)
Relations
d)
All of the above
|
|
Ravi Sharma answered |
In a database, the number of rows inside a table is known as tuples, and if we further divide those tuples (or rows) into those fields, they become the domains. So the correct answer will be B.
The Database Management Query language is generally designed for the _____- a)Support end-users who use English like commands
- b)Specifying the structure of the database
- c)Support in the development of the complex applications software
- d)All of the above
Correct answer is option 'D'. Can you explain this answer?
The Database Management Query language is generally designed for the _____
a)
Support end-users who use English like commands
b)
Specifying the structure of the database
c)
Support in the development of the complex applications software
d)
All of the above
|
|
Gaurav Kumar answered |
The database management query language is generally designed by keeping in mind that it must support the end-users who are familiar with the English-like commands. It should also boost the process of development of the complex applications software and helps in specifying the structure of the database.
Which of the following commands is used to save any transaction permanently into the database?- a)Commit
- b)Rollback
- c)Savepoint
- d)None of the above
Correct answer is option 'A'. Can you explain this answer?
Which of the following commands is used to save any transaction permanently into the database?
a)
Commit
b)
Rollback
c)
Savepoint
d)
None of the above
|
|
Kavya Khanna answered |
Commit
The command used to permanently save a transaction into the database is 'Commit'. When a transaction is executed in a database management system (DBMS), it may involve multiple operations such as inserting, updating, or deleting data. These operations are grouped together as a single unit called a transaction. The purpose of a transaction is to maintain the consistency and integrity of the database.
Explanation:
When a transaction is executed, the changes made to the database are temporarily stored in a transaction log. This log records all the modifications made during the transaction. However, these changes are not immediately applied to the actual database. The 'Commit' command is used to permanently save these changes and make them visible to other users accessing the database.
Importance of Commit:
Committing a transaction is important for several reasons:
1. Data Consistency: By committing a transaction, the changes made to the database are finalized and all related data is updated accordingly. This ensures that the database remains consistent and avoids any conflicting or incorrect information.
2. Data Integrity: Committing a transaction ensures that the changes made are durable and will persist even in the event of a system failure or power outage. It guarantees that the database will be in a consistent state after recovery.
3. Concurrency Control: In a multi-user environment, multiple transactions can be executed concurrently. The 'Commit' command allows one transaction to complete its execution and release any locks it holds on the data, allowing other transactions to access the modified data.
4. Rollback Prevention: Once a transaction is committed, it cannot be rolled back unless a new transaction is executed to undo the changes. Committing a transaction ensures that the changes are permanent and cannot be easily reversed, providing data integrity.
Conclusion:
The 'Commit' command is used to permanently save a transaction into the database, ensuring data consistency, integrity, and durability. It is a crucial step in the transaction process and plays a vital role in maintaining a reliable and accurate database.
The command used to permanently save a transaction into the database is 'Commit'. When a transaction is executed in a database management system (DBMS), it may involve multiple operations such as inserting, updating, or deleting data. These operations are grouped together as a single unit called a transaction. The purpose of a transaction is to maintain the consistency and integrity of the database.
Explanation:
When a transaction is executed, the changes made to the database are temporarily stored in a transaction log. This log records all the modifications made during the transaction. However, these changes are not immediately applied to the actual database. The 'Commit' command is used to permanently save these changes and make them visible to other users accessing the database.
Importance of Commit:
Committing a transaction is important for several reasons:
1. Data Consistency: By committing a transaction, the changes made to the database are finalized and all related data is updated accordingly. This ensures that the database remains consistent and avoids any conflicting or incorrect information.
2. Data Integrity: Committing a transaction ensures that the changes made are durable and will persist even in the event of a system failure or power outage. It guarantees that the database will be in a consistent state after recovery.
3. Concurrency Control: In a multi-user environment, multiple transactions can be executed concurrently. The 'Commit' command allows one transaction to complete its execution and release any locks it holds on the data, allowing other transactions to access the modified data.
4. Rollback Prevention: Once a transaction is committed, it cannot be rolled back unless a new transaction is executed to undo the changes. Committing a transaction ensures that the changes are permanent and cannot be easily reversed, providing data integrity.
Conclusion:
The 'Commit' command is used to permanently save a transaction into the database, ensuring data consistency, integrity, and durability. It is a crucial step in the transaction process and plays a vital role in maintaining a reliable and accurate database.
The given Query can also be replaced with_______:SELECT name, course_id
FROM instructor, teaches
WHERE instructor_ID= teaches_ID; - a)Select name,course_id from teaches,instructor where instructor_id=course_id;
- b)Select name, course_id from instructor natural join teaches;
- c)Select name, course_id from instructor;
- d)Select course_id from instructor join teaches;
Correct answer is option 'B'. Can you explain this answer?
The given Query can also be replaced with_______:
SELECT name, course_id
FROM instructor, teaches
WHERE instructor_ID= teaches_ID;
FROM instructor, teaches
WHERE instructor_ID= teaches_ID;
a)
Select name,course_id from teaches,instructor where instructor_id=course_id;
b)
Select name, course_id from instructor natural join teaches;
c)
Select name, course_id from instructor;
d)
Select course_id from instructor join teaches;
|
|
Varun Datta answered |
Explanation:
The given query is:
SELECT name, course_id
FROM instructor, teaches
WHERE instructor_ID = teaches_ID;
This query retrieves the name and course_id from two tables, instructor and teaches, based on the condition that the instructor_ID is equal to the teaches_ID.
The given options are:
a) Select name, course_id from teaches, instructor where instructor_id = course_id;
b) Select name, course_id from instructor natural join teaches;
c) Select name, course_id from instructor;
d) Select course_id from instructor join teaches;
Option B: Select name, course_id from instructor natural join teaches;
Explanation:
In the given query, "natural join" is used to combine the instructor and teaches tables. It automatically matches the columns with the same names in both tables and returns the result.
The resulting table will contain only the common columns (name and course_id) from both tables. This is why the SELECT statement retrieves only the name and course_id.
Using the natural join eliminates the need to explicitly define the join condition in the WHERE clause. It simplifies the query and makes it easier to read and understand.
Advantages of Option B:
- More concise and readable: Using natural join eliminates the need to explicitly specify the join condition, making the query simpler and easier to understand.
- Automatically matches columns: Natural join matches the columns with the same names in both tables, reducing the chances of errors in specifying the join condition.
- Efficient: By automatically matching the columns, natural join reduces the amount of data that needs to be processed, resulting in better performance.
Conclusion:
Option B is the correct answer as it provides a more concise and efficient way to retrieve the name and course_id from the instructor and teaches tables. The use of natural join simplifies the query and improves readability.
The given query is:
SELECT name, course_id
FROM instructor, teaches
WHERE instructor_ID = teaches_ID;
This query retrieves the name and course_id from two tables, instructor and teaches, based on the condition that the instructor_ID is equal to the teaches_ID.
The given options are:
a) Select name, course_id from teaches, instructor where instructor_id = course_id;
b) Select name, course_id from instructor natural join teaches;
c) Select name, course_id from instructor;
d) Select course_id from instructor join teaches;
Option B: Select name, course_id from instructor natural join teaches;
Explanation:
In the given query, "natural join" is used to combine the instructor and teaches tables. It automatically matches the columns with the same names in both tables and returns the result.
The resulting table will contain only the common columns (name and course_id) from both tables. This is why the SELECT statement retrieves only the name and course_id.
Using the natural join eliminates the need to explicitly define the join condition in the WHERE clause. It simplifies the query and makes it easier to read and understand.
Advantages of Option B:
- More concise and readable: Using natural join eliminates the need to explicitly specify the join condition, making the query simpler and easier to understand.
- Automatically matches columns: Natural join matches the columns with the same names in both tables, reducing the chances of errors in specifying the join condition.
- Efficient: By automatically matching the columns, natural join reduces the amount of data that needs to be processed, resulting in better performance.
Conclusion:
Option B is the correct answer as it provides a more concise and efficient way to retrieve the name and course_id from the instructor and teaches tables. The use of natural join simplifies the query and improves readability.
Which of the following refers to the level of data abstraction that describes exactly how the data actually stored?- a)Conceptual Level
- b)Physical Level
- c)File Level
- d)Logical Level
Correct answer is option 'B'. Can you explain this answer?
Which of the following refers to the level of data abstraction that describes exactly how the data actually stored?
a)
Conceptual Level
b)
Physical Level
c)
File Level
d)
Logical Level
|
|
Ravi Sharma answered |
Data abstraction means displaying or sharing only the data that is needed and hiding from all other data until it is necessary to share it. However, the data abstraction level that describes how the data was actually stored in the user's machine (or system) is known as the Physical level. Therefore the correct answer is B.
For what purpose the DML is provided?- a)Addition of new structure in the database
- b)Manipulation & processing of the database
- c)Definition of the physical structure of the database system
- d)All of the above
Correct answer is option 'B'. Can you explain this answer?
For what purpose the DML is provided?
a)
Addition of new structure in the database
b)
Manipulation & processing of the database
c)
Definition of the physical structure of the database system
d)
All of the above
|
|
Anaya Patel answered |
The term "DML" refers to the data manipulation language, which is commonly used to perform basic operations such as insert data, delete, and update data in a database. So the correct answer will be B.
The database management system can be considered as the collection of ______ that enables us to create and maintain the database.- a)Translators
- b)Programs
- c)Keys
- d)Language activity
Correct answer is option 'B'. Can you explain this answer?
The database management system can be considered as the collection of ______ that enables us to create and maintain the database.
a)
Translators
b)
Programs
c)
Keys
d)
Language activity
|
|
Ravi Sharma answered |
The Database management system can also considered as the set of programs that enables users to create and maintain the database.
The given Query can be replaced with ____________:
SELECT name
FROM instructor1
WHERE salary <= 100000 AND salary >= 90000; - a)SELECT name
FROM instructor1
WHERE salary BETWEEN 100000 AND 90000 - b)SELECT name
FROM instructor|
WHERE salary BETWEEN 90000 AND 100000; - c)SELECT name
FROM instructor1
WHERE salary BETWEEN 90000 AND 100000; - d)SELECT name
FROM instructor!
WHERE salary <= 90000 AND salary>=100000;
Correct answer is option 'C'. Can you explain this answer?
The given Query can be replaced with ____________:
SELECT name
FROM instructor1
WHERE salary <= 100000 AND salary >= 90000;
SELECT name
FROM instructor1
WHERE salary <= 100000 AND salary >= 90000;
a)
SELECT name
FROM instructor1
WHERE salary BETWEEN 100000 AND 90000
FROM instructor1
WHERE salary BETWEEN 100000 AND 90000
b)
SELECT name
FROM instructor|
WHERE salary BETWEEN 90000 AND 100000;
FROM instructor|
WHERE salary BETWEEN 90000 AND 100000;
c)
SELECT name
FROM instructor1
WHERE salary BETWEEN 90000 AND 100000;
FROM instructor1
WHERE salary BETWEEN 90000 AND 100000;
d)
SELECT name
FROM instructor!
WHERE salary <= 90000 AND salary>=100000;
FROM instructor!
WHERE salary <= 90000 AND salary>=100000;
|
|
Gaurav Kumar answered |
The "SQL" contains a comparison known as the "BETWEEN," which is also used in one of the given queries, as you can see. The "BETWEEN" operator is generally used to simplify the "WHERE" clause that is used to specify that the value is greater than one value or greater than some values, less than one or more values.
In the relation model, the relation are generally termed as ________- a)Tuples
- b)Attributes
- c)Rows
- d)Tables
Correct answer is option 'D'. Can you explain this answer?
In the relation model, the relation are generally termed as ________
a)
Tuples
b)
Attributes
c)
Rows
d)
Tables
|
Ishani Gupta answered |
Explanation:
In the relation model, the basic building block is the relation. A relation is also known as a table in a relational database. It consists of rows and columns, where each row represents a record or a tuple, and each column represents an attribute or a field.
Tables:
Tables are the main structures in the relational model. They are used to organize and store data in a structured manner. In a table, data is arranged in rows and columns. Each table has a unique name and consists of a set of attributes or fields.
Attributes:
Attributes are the characteristics or properties of a table. They define the type of data that can be stored in a column. Each attribute has a name and a domain. The domain specifies the range of values that an attribute can take. For example, in a table of employees, the attributes can be employee_id, name, age, and salary.
Tuples:
A tuple, also known as a record, is a row in a table. It represents a single instance or occurrence of data. Each tuple consists of a set of values, one for each attribute of the table. For example, in a table of employees, a tuple may represent a single employee with values for attributes like employee_id, name, age, and salary.
Relation:
A relation is a set of tuples that have the same attributes. It represents a logical connection or association between the tuples. In other words, a relation is a collection of related data stored in a table. Each tuple in a relation is unique, and the order of the tuples does not matter.
Conclusion:
In the relation model, the relations are generally termed as tables. Tables consist of rows, which are also called tuples, and columns, which are also called attributes. The relations represent the logical connection or association between the tuples, and they form the basis of the relational database model.
In the relation model, the basic building block is the relation. A relation is also known as a table in a relational database. It consists of rows and columns, where each row represents a record or a tuple, and each column represents an attribute or a field.
Tables:
Tables are the main structures in the relational model. They are used to organize and store data in a structured manner. In a table, data is arranged in rows and columns. Each table has a unique name and consists of a set of attributes or fields.
Attributes:
Attributes are the characteristics or properties of a table. They define the type of data that can be stored in a column. Each attribute has a name and a domain. The domain specifies the range of values that an attribute can take. For example, in a table of employees, the attributes can be employee_id, name, age, and salary.
Tuples:
A tuple, also known as a record, is a row in a table. It represents a single instance or occurrence of data. Each tuple consists of a set of values, one for each attribute of the table. For example, in a table of employees, a tuple may represent a single employee with values for attributes like employee_id, name, age, and salary.
Relation:
A relation is a set of tuples that have the same attributes. It represents a logical connection or association between the tuples. In other words, a relation is a collection of related data stored in a table. Each tuple in a relation is unique, and the order of the tuples does not matter.
Conclusion:
In the relation model, the relations are generally termed as tables. Tables consist of rows, which are also called tuples, and columns, which are also called attributes. The relations represent the logical connection or association between the tuples, and they form the basis of the relational database model.
Which of the following command is a type of Data Definition language command?- a)Create
- b)Update
- c)Delete
- d)Merge
Correct answer is option 'A'. Can you explain this answer?
Which of the following command is a type of Data Definition language command?
a)
Create
b)
Update
c)
Delete
d)
Merge
|
|
Hansa Sharma answered |
The Data definition language is generally used to maintain or define the structure of the database. For example, creating a table, drop table, alter table. In short, we can say that the command of data definition languages is used to work on the table's schemas inside the database.
Which one of the following is a type of Data Manipulation Command?- a)Create
- b)Alter
- c)Delete
- d)All of the above
Correct answer is option 'C'. Can you explain this answer?
Which one of the following is a type of Data Manipulation Command?
a)
Create
b)
Alter
c)
Delete
d)
All of the above
|
|
Gaurav Kumar answered |
In data manipulation language, the command like select, insert, update, and delete is used to manipulate the information (or data, records), for example create a table, update table delete table, etc. Therefore the correct answer is C.
The term "DFD" stands for?- a)Data file diagram
- b)Data flow document
- c)Data flow diagram
- d)None of the above
Correct answer is option 'C'. Can you explain this answer?
The term "DFD" stands for?
a)
Data file diagram
b)
Data flow document
c)
Data flow diagram
d)
None of the above
|
|
Sounak Nambiar answered |
Explanation:
Data Flow Diagram (DFD):
Data Flow Diagram (DFD) is a graphical representation of the flow of data within an information system. It is a structured analysis and design method that is used to model the flow of data through a system.
Key Points:
- DFDs are commonly used in software engineering to visualize the flow of data within a system.
- They show how data moves from one process to another, how it is stored, and how it is processed.
- DFDs consist of processes, data stores, data flows, and external entities.
- Processes represent the functions or transformations that are performed on the data.
- Data stores represent where data is stored within the system.
- Data flows represent the movement of data between processes and data stores.
- External entities represent the sources or destinations of data outside the system.
Importance of DFDs:
- DFDs help in understanding the system's data flow and can aid in identifying areas for improvement.
- They provide a visual representation of the system, making it easier to communicate with stakeholders.
- DFDs can help in identifying errors or inefficiencies in the system's data flow.
In conclusion, Data Flow Diagrams (DFDs) are an essential tool in software engineering for visualizing the flow of data within a system. They help in understanding how data moves through the system and are crucial for system analysis and design.
Data Flow Diagram (DFD):
Data Flow Diagram (DFD) is a graphical representation of the flow of data within an information system. It is a structured analysis and design method that is used to model the flow of data through a system.
Key Points:
- DFDs are commonly used in software engineering to visualize the flow of data within a system.
- They show how data moves from one process to another, how it is stored, and how it is processed.
- DFDs consist of processes, data stores, data flows, and external entities.
- Processes represent the functions or transformations that are performed on the data.
- Data stores represent where data is stored within the system.
- Data flows represent the movement of data between processes and data stores.
- External entities represent the sources or destinations of data outside the system.
Importance of DFDs:
- DFDs help in understanding the system's data flow and can aid in identifying areas for improvement.
- They provide a visual representation of the system, making it easier to communicate with stakeholders.
- DFDs can help in identifying errors or inefficiencies in the system's data flow.
In conclusion, Data Flow Diagrams (DFDs) are an essential tool in software engineering for visualizing the flow of data within a system. They help in understanding how data moves through the system and are crucial for system analysis and design.
Which of the following is a top-down approach in which the entity's higher level can be divided into two lower sub-entities?- a)Aggregation
- b)Generalization
- c)Specialization
- d)All of the above
Correct answer is option 'C'. Can you explain this answer?
Which of the following is a top-down approach in which the entity's higher level can be divided into two lower sub-entities?
a)
Aggregation
b)
Generalization
c)
Specialization
d)
All of the above
|
|
Hansa Sharma answered |
In specialization, the top-down approach is used, and it is apposite to the generalization.
In the specialization, the higher-level entity can be divided into sub lower entities. It is generally used for identifying the subset of an entity set which share the distinguishing characteristics.
To understand it more clearly, consider the following example:
Suppose you have an entity, e.g., A vehicle. So through the specialization, you can be divided further into sub-entities like two-wheelers and four-wheelers. Therefore the correct answer is C.
In the specialization, the higher-level entity can be divided into sub lower entities. It is generally used for identifying the subset of an entity set which share the distinguishing characteristics.
To understand it more clearly, consider the following example:
Suppose you have an entity, e.g., A vehicle. So through the specialization, you can be divided further into sub-entities like two-wheelers and four-wheelers. Therefore the correct answer is C.
Which of the following provides the ability to query information from the database and insert tuples into, delete tuples from, and modify tuples in the database?- a)DML(Data Manipulation Language)
- b)DDL(Data Definition Language)
- c)Query
- d)Relational Schema
Correct answer is option 'A'. Can you explain this answer?
Which of the following provides the ability to query information from the database and insert tuples into, delete tuples from, and modify tuples in the database?
a)
DML(Data Manipulation Language)
b)
DDL(Data Definition Language)
c)
Query
d)
Relational Schema
|
|
Varun Chauhan answered |
DML (Data Manipulation Language) provides the ability to query information from the database and perform various operations on the data such as inserting, deleting, and modifying tuples.
DML is a subset of SQL (Structured Query Language) and is used to interact with the data stored in a database. It allows users to retrieve specific data based on certain conditions and make changes to the data as needed.
Here is a detailed explanation of why DML is the correct option:
1. DML Operations:
DML consists of various operations that manipulate the data in a database. These operations include:
- SELECT: This operation is used to retrieve specific data from one or more tables based on certain conditions.
- INSERT: This operation is used to add new tuples (rows) into a table, providing the values for each column.
- UPDATE: This operation is used to modify existing tuples in a table by changing the values of one or more columns.
- DELETE: This operation is used to remove tuples from a table based on certain conditions.
2. Querying Information:
DML provides the ability to query information from the database using the SELECT statement. This allows users to retrieve specific data based on criteria such as filtering by specific values, sorting the data, or joining multiple tables to fetch related information.
3. Modifying Tuples:
DML allows users to modify tuples in the database using the UPDATE and DELETE statements. The UPDATE statement can be used to change the values of one or more columns in existing tuples, while the DELETE statement can be used to remove tuples that meet certain conditions.
4. Inserting Tuples:
DML also allows users to insert new tuples into a table using the INSERT statement. This statement specifies the table name and provides the values for each column in the new tuple.
5. DDL vs. DML:
While both DDL (Data Definition Language) and DML are part of SQL, they serve different purposes. DDL is used to define the structure of the database, including creating tables, defining constraints, and modifying the schema. On the other hand, DML focuses on manipulating the data stored in the database.
In conclusion, DML provides the necessary tools to query information from the database and perform operations such as inserting, deleting, and modifying tuples. It is a fundamental component of SQL and allows users to interact with the data in a database effectively.
DML is a subset of SQL (Structured Query Language) and is used to interact with the data stored in a database. It allows users to retrieve specific data based on certain conditions and make changes to the data as needed.
Here is a detailed explanation of why DML is the correct option:
1. DML Operations:
DML consists of various operations that manipulate the data in a database. These operations include:
- SELECT: This operation is used to retrieve specific data from one or more tables based on certain conditions.
- INSERT: This operation is used to add new tuples (rows) into a table, providing the values for each column.
- UPDATE: This operation is used to modify existing tuples in a table by changing the values of one or more columns.
- DELETE: This operation is used to remove tuples from a table based on certain conditions.
2. Querying Information:
DML provides the ability to query information from the database using the SELECT statement. This allows users to retrieve specific data based on criteria such as filtering by specific values, sorting the data, or joining multiple tables to fetch related information.
3. Modifying Tuples:
DML allows users to modify tuples in the database using the UPDATE and DELETE statements. The UPDATE statement can be used to change the values of one or more columns in existing tuples, while the DELETE statement can be used to remove tuples that meet certain conditions.
4. Inserting Tuples:
DML also allows users to insert new tuples into a table using the INSERT statement. This statement specifies the table name and provides the values for each column in the new tuple.
5. DDL vs. DML:
While both DDL (Data Definition Language) and DML are part of SQL, they serve different purposes. DDL is used to define the structure of the database, including creating tables, defining constraints, and modifying the schema. On the other hand, DML focuses on manipulating the data stored in the database.
In conclusion, DML provides the necessary tools to query information from the database and perform operations such as inserting, deleting, and modifying tuples. It is a fundamental component of SQL and allows users to interact with the data in a database effectively.
The architecture of a database can be viewed as the ________- a)One level
- b)Two-level
- c)Three-level
- d)Four level
Correct answer is option 'C'. Can you explain this answer?
The architecture of a database can be viewed as the ________
a)
One level
b)
Two-level
c)
Three-level
d)
Four level
|
|
Abhay Sharma answered |
Three-level
- The architecture of a database refers to the overall structure and organization of the database system. It determines how the data is stored, accessed, and managed within the system. The architecture can be viewed as a hierarchy of different levels.
- The three-level architecture, also known as the ANSI-SPARC architecture, is a widely used approach to database design. It divides the database system into three distinct levels, each serving a specific purpose.
- The three levels of database architecture are:
1. External Level:
- The external level is the highest level of abstraction and is concerned with the views or representations of the data that are relevant to individual users or groups of users.
- It allows different users to have different views of the data, depending on their specific requirements.
- Users at this level interact with the database through various applications or tools and define their own logical schemas or views.
2. Conceptual Level:
- The conceptual level represents the overall logical structure of the entire database.
- It provides an integrated view of the data and hides the physical details of storage and implementation from the users.
- The conceptual schema defines the entities, relationships, and constraints that exist in the database.
- It serves as a blueprint for the database design and is independent of any specific implementation technology.
3. Internal Level:
- The internal level is the lowest level of abstraction and deals with the physical storage and representation of the data.
- It describes how the data is actually stored on the storage media, such as disks or tapes.
- The internal schema defines the record formats, file organization, indexing techniques, and other physical implementation details.
- It is responsible for translating the logical view into the physical representation of the data.
- The three-level architecture provides a clear separation between the different aspects of the database system, allowing for flexibility, scalability, and independence between the user applications and the physical storage. It also helps in maintaining data integrity, security, and efficient data retrieval and manipulation.
- The architecture of a database refers to the overall structure and organization of the database system. It determines how the data is stored, accessed, and managed within the system. The architecture can be viewed as a hierarchy of different levels.
- The three-level architecture, also known as the ANSI-SPARC architecture, is a widely used approach to database design. It divides the database system into three distinct levels, each serving a specific purpose.
- The three levels of database architecture are:
1. External Level:
- The external level is the highest level of abstraction and is concerned with the views or representations of the data that are relevant to individual users or groups of users.
- It allows different users to have different views of the data, depending on their specific requirements.
- Users at this level interact with the database through various applications or tools and define their own logical schemas or views.
2. Conceptual Level:
- The conceptual level represents the overall logical structure of the entire database.
- It provides an integrated view of the data and hides the physical details of storage and implementation from the users.
- The conceptual schema defines the entities, relationships, and constraints that exist in the database.
- It serves as a blueprint for the database design and is independent of any specific implementation technology.
3. Internal Level:
- The internal level is the lowest level of abstraction and deals with the physical storage and representation of the data.
- It describes how the data is actually stored on the storage media, such as disks or tapes.
- The internal schema defines the record formats, file organization, indexing techniques, and other physical implementation details.
- It is responsible for translating the logical view into the physical representation of the data.
- The three-level architecture provides a clear separation between the different aspects of the database system, allowing for flexibility, scalability, and independence between the user applications and the physical storage. It also helps in maintaining data integrity, security, and efficient data retrieval and manipulation.
Which of the following refers to the number of tuples in a relation?- a)Entity
- b)Column
- c)Cardinality
- d)None of the above
Correct answer is option 'C'. Can you explain this answer?
Which of the following refers to the number of tuples in a relation?
a)
Entity
b)
Column
c)
Cardinality
d)
None of the above
|
|
Kavya Khanna answered |
Cardinality
Cardinality refers to the number of tuples (rows) in a relation (table) in a database. It represents the size or extent of a relation and provides information about the number of records or instances in a table.
Explanation:
When designing a database, it is important to determine the cardinality of the relationships between entities. Cardinality can be classified as one-to-one, one-to-many, or many-to-many.
- One-to-one: In a one-to-one relationship, each record in one table is associated with only one record in another table. For example, in a database that stores employee information, each employee may have only one unique employee ID, and this employee ID is linked to a single record in the employee table.
- One-to-many: In a one-to-many relationship, a record in one table can be associated with one or more records in another table. For example, in a database that stores customer and order information, a customer can have multiple orders, but each order is associated with only one customer.
- Many-to-many: In a many-to-many relationship, records in one table can be associated with multiple records in another table, and vice versa. For example, in a database that stores student and course information, a student can enroll in multiple courses, and each course can have multiple students.
In all these cases, the cardinality of the relationships determines how the tables are connected and how the data is organized. It helps to establish the structure and integrity of the database.
Conclusion:
In the given options, the term that refers to the number of tuples in a relation is cardinality. It is an important concept in database management systems and helps in understanding the size and relationships between tables.
Cardinality refers to the number of tuples (rows) in a relation (table) in a database. It represents the size or extent of a relation and provides information about the number of records or instances in a table.
Explanation:
When designing a database, it is important to determine the cardinality of the relationships between entities. Cardinality can be classified as one-to-one, one-to-many, or many-to-many.
- One-to-one: In a one-to-one relationship, each record in one table is associated with only one record in another table. For example, in a database that stores employee information, each employee may have only one unique employee ID, and this employee ID is linked to a single record in the employee table.
- One-to-many: In a one-to-many relationship, a record in one table can be associated with one or more records in another table. For example, in a database that stores customer and order information, a customer can have multiple orders, but each order is associated with only one customer.
- Many-to-many: In a many-to-many relationship, records in one table can be associated with multiple records in another table, and vice versa. For example, in a database that stores student and course information, a student can enroll in multiple courses, and each course can have multiple students.
In all these cases, the cardinality of the relationships determines how the tables are connected and how the data is organized. It helps to establish the structure and integrity of the database.
Conclusion:
In the given options, the term that refers to the number of tuples in a relation is cardinality. It is an important concept in database management systems and helps in understanding the size and relationships between tables.
Which one of the following commands is used to restore the database to the last committed state?- a)Savepoint
- b)Rollback
- c)Commit
- d)Both A & B
Correct answer is option 'B'. Can you explain this answer?
Which one of the following commands is used to restore the database to the last committed state?
a)
Savepoint
b)
Rollback
c)
Commit
d)
Both A & B
|
|
Hansa Sharma answered |
As we all know that while working with the Transactions, the Transaction Control Language is used. To restore the database to the last committed state ( or to undo the latest changes), the "rollback" command is used that belongs to the Transaction Control Language.
To which of the following the term "DBA" referred?- a)Data Bank Administrator
- b)Database Administrator
- c)Data Administrator
- d)None of the above
Correct answer is option 'B'. Can you explain this answer?
To which of the following the term "DBA" referred?
a)
Data Bank Administrator
b)
Database Administrator
c)
Data Administrator
d)
None of the above
|
|
Charvi Sharma answered |
"the term" is not specified in the question. Please provide more information or options for us to assist you.
The term "FAT" is stands for_____- a)File Allocation Tree
- b)File Allocation Table
- c)File Allocation Graph
- d)All of the above
Correct answer is option 'B'. Can you explain this answer?
The term "FAT" is stands for_____
a)
File Allocation Tree
b)
File Allocation Table
c)
File Allocation Graph
d)
All of the above
|
|
Hansa Sharma answered |
The term "FAT" can be described as a file structure (or file architecture). In which all the information about the files where they are stored and where all these files need to be stored or in which directory, all that information generally stored in the file structure. Therefore the Operating system creates a table in which all the files and clusters are stored, known as the file allocation table.
The term "SQL" stands for- a)Standard query language
- b)Sequential query language
- c)Structured query language
- d)Server-side query language
Correct answer is option 'C'. Can you explain this answer?
The term "SQL" stands for
a)
Standard query language
b)
Sequential query language
c)
Structured query language
d)
Server-side query language
|
|
Hansa Sharma answered |
The term "SQL" stands for the structured query language, which is one of the most widely, used programming languages for relational databases. It can also be used for managing and organizing data in all sorts of systems in which different data relationships exist. Therefore the correct answer is C.
Which one of the following refers to the total view of the database content?- a)Conceptual view
- b)Physical view
- c)Internal view
- d)External view
Correct answer is option 'A'. Can you explain this answer?
Which one of the following refers to the total view of the database content?
a)
Conceptual view
b)
Physical view
c)
Internal view
d)
External view
|
|
Ravi Sharma answered |
The conceptual view refers to the total view of the content available in the database. Therefore the correct answer is A.
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