Database Chapters 4,5,7 Midterm 2 Quiz

1. A transaction is the complete set of closely related update commands that must all be done, or none of them done, for the database to remain valid

True

False

A transaction is a set of commands that are executed together as a single unit. These commands are closely related and must all be completed successfully for the database to remain in a valid state. If any of the commands fail or are not completed, the entire transaction is rolled back and the database is left unchanged. Therefore, the statement that a transaction is the complete set of closely related update commands that must all be done, or none of them done, for the database to remain valid is true.

Explanation

A transaction is a set of commands that are executed together as a single unit. These commands are closely related and must all be completed successfully for the database to remain in a valid state. If any of the commands fail or are not completed, the entire transaction is rolled back and the database is left unchanged. Therefore, the statement that a transaction is the complete set of closely related update commands that must all be done, or none of them done, for the database to remain valid is true.

2. The following produce the same result: SQL> select customer_name, customer_city from customer, salesman where customer.salesman_id = salesman.salesman_id and salesman.lname = 'SMITH'; SQL> select customer_name, customer_city from customer where customer.salesman_id = (select salesman_id from salesman where lname = 'SMITH');

True

False

Both SQL queries are retrieving the same result. The first query uses a join between the customer and salesman tables to filter the results based on the salesman's last name being 'SMITH'. The second query uses a subquery to retrieve the salesman_id for the salesman with the last name 'SMITH', and then filters the customer table based on that salesman_id. Both approaches achieve the same result, so the answer is true.

Explanation

Both SQL queries are retrieving the same result. The first query uses a join between the customer and salesman tables to filter the results based on the salesman's last name being 'SMITH'. The second query uses a subquery to retrieve the salesman_id for the salesman with the last name 'SMITH', and then filters the customer table based on that salesman_id. Both approaches achieve the same result, so the answer is true.

3. When EXISTS or NOT EXISTS is used in a subquery, the select list of the subquery will usually just select all columns as a placeholder because it doesnt matter which columns are returned

True

False

When EXISTS or NOT EXISTS is used in a subquery, the focus is on whether or not any rows exist that satisfy a certain condition. The actual data returned by the subquery is not important in this case. Therefore, the select list of the subquery will usually just select all columns as a placeholder, as the specific columns being returned do not matter. This allows the query to focus solely on the existence of the desired rows, rather than the actual data they contain.

Explanation

When EXISTS or NOT EXISTS is used in a subquery, the focus is on whether or not any rows exist that satisfy a certain condition. The actual data returned by the subquery is not important in this case. Therefore, the select list of the subquery will usually just select all columns as a placeholder, as the specific columns being returned do not matter. This allows the query to focus solely on the existence of the desired rows, rather than the actual data they contain.

4. Persistent stored modules are extensions defined in SQL:1999 that include the capability to add and drop modules of code

True

False

Persistent stored modules are indeed extensions defined in SQL:1999 that include the capability to add and drop modules of code. These modules are stored in the database and can be accessed and executed by the database management system. They provide a way to encapsulate and organize code logic within the database, allowing for easier maintenance and reusability. This feature enhances the functionality and flexibility of SQL by enabling the creation, modification, and deletion of modules as needed. Therefore, the statement "True" is the correct answer.

Explanation

Persistent stored modules are indeed extensions defined in SQL:1999 that include the capability to add and drop modules of code. These modules are stored in the database and can be accessed and executed by the database management system. They provide a way to encapsulate and organize code logic within the database, allowing for easier maintenance and reusability. This feature enhances the functionality and flexibility of SQL by enabling the creation, modification, and deletion of modules as needed. Therefore, the statement "True" is the correct answer.

5. In order to find out what customers have not placed an order for a particular item, one might use the NOT qualifier along with the IN qualifier

True

False

To find out what customers have not placed an order for a particular item, using the NOT qualifier along with the IN qualifier is an effective approach. The NOT qualifier negates the condition specified in the query, while the IN qualifier checks if a value matches any of the values in a specified list. By combining these qualifiers, we can retrieve the customers who are not included in the list of customers who have ordered the particular item. Therefore, the statement is true.

Explanation

To find out what customers have not placed an order for a particular item, using the NOT qualifier along with the IN qualifier is an effective approach. The NOT qualifier negates the condition specified in the query, while the IN qualifier checks if a value matches any of the values in a specified list. By combining these qualifiers, we can retrieve the customers who are not included in the list of customers who have ordered the particular item. Therefore, the statement is true.

6. An SQL query that implements an outer join will return rows that do not have matching values in common columns

True

False

An SQL query that implements an outer join combines rows from two or more tables, even if there are no matching values in the common columns. This means that the resulting query will include all rows from one table, and the matching rows from the other table, as well as any rows that do not have matching values in the common columns. Therefore, the statement "An SQL query that implements an outer join will return rows that do not have matching values in common columns" is true.

Explanation

An SQL query that implements an outer join combines rows from two or more tables, even if there are no matching values in the common columns. This means that the resulting query will include all rows from one table, and the matching rows from the other table, as well as any rows that do not have matching values in the common columns. Therefore, the statement "An SQL query that implements an outer join will return rows that do not have matching values in common columns" is true.

7. The joining condition of an equi-join based upon an equality

True

False

In an equi-join, the joining condition is based upon an equality. This means that the join operation is performed by matching the values of a specified column in both tables, and only the rows with matching values are included in the result. Therefore, the statement "The joining condition of an equi-join is based upon an equality" is true.

Explanation

In an equi-join, the joining condition is based upon an equality. This means that the join operation is performed by matching the values of a specified column in both tables, and only the rows with matching values are included in the result. Therefore, the statement "The joining condition of an equi-join is based upon an equality" is true.

8. RDBMS's store database definition information in system-created tables which can be considered a data dictionary

True

False

RDBMS (Relational Database Management Systems) do store database definition information in system-created tables, which can be considered a data dictionary. This data dictionary contains metadata about the database, such as the names and types of tables, columns, constraints, and other database objects. It provides a centralized repository for storing and managing this information, allowing for easy access and maintenance of the database structure. Therefore, the statement "RDBMS's store database definition information in system-created tables which can be considered a data dictionary" is true.

Explanation

RDBMS (Relational Database Management Systems) do store database definition information in system-created tables, which can be considered a data dictionary. This data dictionary contains metadata about the database, such as the names and types of tables, columns, constraints, and other database objects. It provides a centralized repository for storing and managing this information, allowing for easy access and maintenance of the database structure. Therefore, the statement "RDBMS's store database definition information in system-created tables which can be considered a data dictionary" is true.

9. The UNION clause is used to combine the output from multiple queries into a single result table

True

False

The UNION clause is indeed used to combine the output from multiple queries into a single result table. It allows you to retrieve data from different tables or views and present it as a unified result set. The columns in the result sets of the queries must have the same data types and be in the same order. The UNION operation removes duplicate rows from the final result.

Explanation

The UNION clause is indeed used to combine the output from multiple queries into a single result table. It allows you to retrieve data from different tables or views and present it as a unified result set. The columns in the result sets of the queries must have the same data types and be in the same order. The UNION operation removes duplicate rows from the final result.

10. SQL:200n allows one to calculate linear regressions, moving averages and correlations without moving the data outside of the database

True

False

SQL:200n, a version of SQL, allows users to perform calculations such as linear regressions, moving averages, and correlations directly within the database, without the need to move the data outside. This means that users can leverage the power and efficiency of the database system to perform complex calculations and analysis on large datasets, without the need for additional tools or resources. This capability enhances the convenience and performance of data analysis tasks, making it a valuable feature for users working with SQL databases.

Explanation

SQL:200n, a version of SQL, allows users to perform calculations such as linear regressions, moving averages, and correlations directly within the database, without the need to move the data outside. This means that users can leverage the power and efficiency of the database system to perform complex calculations and analysis on large datasets, without the need for additional tools or resources. This capability enhances the convenience and performance of data analysis tasks, making it a valuable feature for users working with SQL databases.

11. Joining tables or using a subquery may produce the same result

True

False

Joining tables or using a subquery can produce the same result because both methods allow us to combine data from multiple tables. Joining tables involves combining rows from two or more tables based on a related column, while a subquery involves nesting one query inside another to retrieve data based on a condition. In both cases, we can obtain the desired result by selecting specific columns or applying filters. Therefore, it is true that joining tables or using a subquery can yield the same outcome.

Explanation

Joining tables or using a subquery can produce the same result because both methods allow us to combine data from multiple tables. Joining tables involves combining rows from two or more tables based on a related column, while a subquery involves nesting one query inside another to retrieve data based on a condition. In both cases, we can obtain the desired result by selecting specific columns or applying filters. Therefore, it is true that joining tables or using a subquery can yield the same outcome.

12. Combining a table with iself results in a faster query

True

False

Combining a table with itself does not result in a faster query. In fact, it can often lead to slower performance due to the increased complexity of the query. When a table is joined with itself, it essentially duplicates the data and requires more processing power to compare and match the rows. This can result in longer execution times and decreased efficiency. Therefore, the statement is false.

Explanation

Combining a table with itself does not result in a faster query. In fact, it can often lead to slower performance due to the increased complexity of the query. When a table is joined with itself, it essentially duplicates the data and requires more processing power to compare and match the rows. This can result in longer execution times and decreased efficiency. Therefore, the statement is false.

13. A correlated subquery is executed once for each iteration through the outer loop

True

False

A correlated subquery is a subquery that references a column from the outer query. It is executed once for each row in the outer query's result set. This means that for every iteration through the outer loop, the correlated subquery is executed. Therefore, the given statement that a correlated subquery is executed once for each iteration through the outer loop is true.

Explanation

A correlated subquery is a subquery that references a column from the outer query. It is executed once for each row in the outer query's result set. This means that for every iteration through the outer loop, the correlated subquery is executed. Therefore, the given statement that a correlated subquery is executed once for each iteration through the outer loop is true.

14. Designing physical files requires __________ of where and when data are used in various ways

Maps

Descriptions

Keys

When designing physical files, it is important to have descriptions of where and when data are used in various ways. This means that the designer needs to have a clear understanding of how the data will be accessed, manipulated, and utilized within the system. By having detailed descriptions of these aspects, the designer can ensure that the physical files are organized and structured in a way that supports efficient data management and retrieval.

Explanation

When designing physical files, it is important to have descriptions of where and when data are used in various ways. This means that the designer needs to have a clear understanding of how the data will be accessed, manipulated, and utilized within the system. By having detailed descriptions of these aspects, the designer can ensure that the physical files are organized and structured in a way that supports efficient data management and retrieval.

15. The natural join is very rarely used

True

False

The statement that the natural join is very rarely used is false. The natural join is a type of join in relational databases that combines rows from two tables based on matching values in columns with the same name and data type. It is commonly used when there is a need to combine data from multiple tables without explicitly specifying the join conditions. While other types of joins may be more commonly used in certain scenarios, the natural join still has its applications and can be a useful tool in database queries and operations.

Explanation

The statement that the natural join is very rarely used is false. The natural join is a type of join in relational databases that combines rows from two tables based on matching values in columns with the same name and data type. It is commonly used when there is a need to combine data from multiple tables without explicitly specifying the join conditions. While other types of joins may be more commonly used in certain scenarios, the natural join still has its applications and can be a useful tool in database queries and operations.

16. While triggers run automatically, ________________ do not and have to be called

Trapdoors

Routines

Selects

Updates

Routines do not run automatically like triggers. They need to be explicitly called or invoked in order to execute their defined set of instructions. Triggers, on the other hand, are automatically triggered by specific events or actions in the database. Therefore, the correct answer is "routines".

Explanation

Routines do not run automatically like triggers. They need to be explicitly called or invoked in order to execute their defined set of instructions. Triggers, on the other hand, are automatically triggered by specific events or actions in the database. Therefore, the correct answer is "routines".

17. A type of query that is palced within a WHERE or HAVING clause of another query is called a:

Master query

Subquery

Superquery

Multi-query

A subquery is a type of query that is placed within a WHERE or HAVING clause of another query. It is used to retrieve data that is based on the results of the outer query. By using a subquery, more complex and specific conditions can be applied to filter the results of the main query. This allows for more advanced and targeted data retrieval and analysis.

Explanation

A subquery is a type of query that is placed within a WHERE or HAVING clause of another query. It is used to retrieve data that is based on the results of the outer query. By using a subquery, more complex and specific conditions can be applied to filter the results of the main query. This allows for more advanced and targeted data retrieval and analysis.

18. START CH 7 - Constraints are a special case of triggers

True

False

Constraints are a special case of triggers because both constraints and triggers are used to enforce certain conditions or rules in a database. However, constraints are predefined rules that are automatically enforced by the database management system, while triggers are user-defined rules that are executed automatically in response to certain events. Therefore, constraints can be seen as a specific type or subset of triggers, as they are a mechanism for enforcing rules in a database.

Explanation

Constraints are a special case of triggers because both constraints and triggers are used to enforce certain conditions or rules in a database. However, constraints are predefined rules that are automatically enforced by the database management system, while triggers are user-defined rules that are executed automatically in response to certain events. Therefore, constraints can be seen as a specific type or subset of triggers, as they are a mechanism for enforcing rules in a database.

19. DBA_USERS contains comments on all tables in an Oracle databse

True

False

DBA_USERS does not contain comments on all tables in an Oracle database. It is a data dictionary view that provides information about all users of the database. The comments on tables can be found in the DBA_TAB_COMMENTS view, which specifically stores comments on tables. Therefore, the correct answer is False.

Explanation

DBA_USERS does not contain comments on all tables in an Oracle database. It is a data dictionary view that provides information about all users of the database. The comments on tables can be found in the DBA_TAB_COMMENTS view, which specifically stores comments on tables. Therefore, the correct answer is False.

20. Correlated subqueries are less efficient than queries that do not use nesting

True

False

Correlated subqueries are less efficient than queries that do not use nesting because in a correlated subquery, the subquery is executed for each row of the outer query. This means that the subquery is dependent on the result of the outer query, and it needs to be executed multiple times. This can lead to slower performance and increased resource usage compared to queries that do not use nesting.

Explanation

Correlated subqueries are less efficient than queries that do not use nesting because in a correlated subquery, the subquery is executed for each row of the outer query. This means that the subquery is dependent on the result of the outer query, and it needs to be executed multiple times. This can lead to slower performance and increased resource usage compared to queries that do not use nesting.

21. When the value of one attribute (the determinant) determines the value of another attribute, it is called:

Functional dependency

Merged relation

Transitive dependency

Full dependency

Functional dependency refers to a situation where the value of one attribute determines the value of another attribute. In other words, if we know the value of one attribute, we can determine the value of another attribute based on that. This concept is important in database design and normalization, as it helps to ensure data integrity and eliminate redundancy. Therefore, the correct answer is functional dependency.

Explanation

Functional dependency refers to a situation where the value of one attribute determines the value of another attribute. In other words, if we know the value of one attribute, we can determine the value of another attribute based on that. This concept is important in database design and normalization, as it helps to ensure data integrity and eliminate redundancy. Therefore, the correct answer is functional dependency.

22. The __________ states that no primary key attribute may be null

Referential integrity constraint

Entity integrity rule

Partial specialization rule

Range domain rule

The entity integrity rule states that no primary key attribute may be null. This means that every entity in a table must have a unique identifier (primary key) and this identifier cannot have a null value. This rule ensures that each entity in a table is uniquely identified and helps maintain the integrity and consistency of the data.

Explanation

The entity integrity rule states that no primary key attribute may be null. This means that every entity in a table must have a unique identifier (primary key) and this identifier cannot have a null value. This rule ensures that each entity in a table is uniquely identified and helps maintain the integrity and consistency of the data.

23. A join operation:

Brings together data from two different fields

Causes two tables with a common domain to be combined into a single table or view

Causes two disparate tables to be combined into a single table or view

Is used to combine indexing operations

A join operation is used to combine two tables that have a common domain, meaning they share a common field or attribute. This operation allows the data from both tables to be merged into a single table or view, creating a unified dataset that includes information from both tables. By matching the values in the common field, the join operation brings together related data from the two tables, facilitating analysis and retrieval of information.

Explanation

A join operation is used to combine two tables that have a common domain, meaning they share a common field or attribute. This operation allows the data from both tables to be merged into a single table or view, creating a unified dataset that includes information from both tables. By matching the values in the common field, the join operation brings together related data from the two tables, facilitating analysis and retrieval of information.

24. A primary key that consists of more than one attribute is called a:

Foreign key

Composite key

Multivalued key

Cardinal key

A primary key that consists of more than one attribute is called a composite key. This means that the primary key is made up of multiple columns in a table, rather than just a single column. Using a composite key allows for a more precise and unique way of identifying records in a table, as it takes into account multiple attributes to create a unique identifier.

Explanation

A primary key that consists of more than one attribute is called a composite key. This means that the primary key is made up of multiple columns in a table, rather than just a single column. Using a composite key allows for a more precise and unique way of identifying records in a table, as it takes into account multiple attributes to create a unique identifier.

25. In which type of file is multiple key retrieval not possible

Hashed

Other options werent in PDF

Multiple key retrieval is not possible in a hashed file. In a hashed file, the keys are mapped to specific locations using a hash function. This allows for quick access to individual records based on their keys. However, since the keys are transformed into specific locations, it becomes difficult to retrieve multiple keys simultaneously. In other types of files, such as indexed or sequential files, it is possible to retrieve multiple keys efficiently.

Explanation

Multiple key retrieval is not possible in a hashed file. In a hashed file, the keys are mapped to specific locations using a hash function. This allows for quick access to individual records based on their keys. However, since the keys are transformed into specific locations, it becomes difficult to retrieve multiple keys simultaneously. In other types of files, such as indexed or sequential files, it is possible to retrieve multiple keys efficiently.

26. EXISTS takes a value of false if the subquery returns an intermediate result set

True

False

The EXISTS operator in SQL returns true if the subquery returns at least one row, and false if the subquery returns an empty result set. It does not return false if the subquery returns an intermediate result set. Therefore, the given statement is incorrect.

Explanation

The EXISTS operator in SQL returns true if the subquery returns at least one row, and false if the subquery returns an empty result set. It does not return false if the subquery returns an intermediate result set. Therefore, the given statement is incorrect.

27. Dynamic SQL:

Is used to generate appropriate SQL code on the fly, as an application is processing

Is quite volatile

Creates a less flexible application

Dynamic SQL is a technique used to generate SQL code dynamically during runtime. It allows applications to construct and execute SQL statements based on specific conditions or user inputs. This flexibility enables developers to create more adaptable and customizable applications. Unlike static SQL, which is predefined and fixed, dynamic SQL allows for the generation of SQL code on the fly, making it suitable for scenarios where the SQL code needs to be determined at runtime.

Explanation

Dynamic SQL is a technique used to generate SQL code dynamically during runtime. It allows applications to construct and execute SQL statements based on specific conditions or user inputs. This flexibility enables developers to create more adaptable and customizable applications. Unlike static SQL, which is predefined and fixed, dynamic SQL allows for the generation of SQL code on the fly, making it suitable for scenarios where the SQL code needs to be determined at runtime.

28. SQL-invoked routines can be:

Procedures

Functions

All of the above

None of the above

SQL-invoked routines can be procedures or functions. Procedures are a set of SQL statements that perform a specific task and can be invoked using the CALL statement. Functions, on the other hand, return a single value and can be used in SQL statements. Therefore, both procedures and functions are examples of SQL-invoked routines, making "all of the above" the correct answer.

Explanation

SQL-invoked routines can be procedures or functions. Procedures are a set of SQL statements that perform a specific task and can be invoked using the CALL statement. Functions, on the other hand, return a single value and can be used in SQL statements. Therefore, both procedures and functions are examples of SQL-invoked routines, making "all of the above" the correct answer.

29. When all multivalued attributes have been removed from a relation , it is said to be in:

First normal form

Second normal form

Boyce-Codd normal form

Third normal form

When all multivalued attributes have been removed from a relation, it is said to be in the first normal form. This means that each attribute in the relation contains only atomic values, and there are no repeating groups or arrays of values within a single attribute. The first normal form is the basic level of normalization and ensures that the relation is free from redundancy and anomalies.

Explanation

When all multivalued attributes have been removed from a relation, it is said to be in the first normal form. This means that each attribute in the relation contains only atomic values, and there are no repeating groups or arrays of values within a single attribute. The first normal form is the basic level of normalization and ensures that the relation is free from redundancy and anomalies.

30. One field or combination of fields for which more than one record may have the same combination of values is called a(n):

Secondary key

Index

Composite key

Linked key

A secondary key is a field or combination of fields in a database table that allows more than one record to have the same combination of values. It is used to provide an alternate way to uniquely identify records in addition to the primary key. This can be useful in situations where there is a need to efficiently search and retrieve data based on criteria other than the primary key.

Explanation

A secondary key is a field or combination of fields in a database table that allows more than one record to have the same combination of values. It is used to provide an alternate way to uniquely identify records in addition to the primary key. This can be useful in situations where there is a need to efficiently search and retrieve data based on criteria other than the primary key.

31. Explicit commands to manage transactions are needed when:

A transaction consists of just one SQL command

Multiple SQL commands must be run as part of a transaction

Autocommit is set to off

None of the above

Explicit commands to manage transactions are needed when multiple SQL commands must be run as part of a transaction. In a transaction, multiple SQL commands are grouped together as a single unit of work that must be executed atomically. This means that either all the commands in the transaction are executed successfully, or none of them are executed at all. To ensure this atomicity, explicit commands such as BEGIN TRANSACTION, COMMIT, and ROLLBACK are used to start, end, and undo the transaction, respectively. If there is only one SQL command or if autocommit is set to off, these explicit commands are not necessary as each command is treated as a separate transaction.

Explanation

Explicit commands to manage transactions are needed when multiple SQL commands must be run as part of a transaction. In a transaction, multiple SQL commands are grouped together as a single unit of work that must be executed atomically. This means that either all the commands in the transaction are executed successfully, or none of them are executed at all. To ensure this atomicity, explicit commands such as BEGIN TRANSACTION, COMMIT, and ROLLBACK are used to start, end, and undo the transaction, respectively. If there is only one SQL command or if autocommit is set to off, these explicit commands are not necessary as each command is treated as a separate transaction.

32. Distributing the rows of data into separate files is called:

Normalization

Horizontal partitioning

Vertical partitioning

File allocation

Horizontal partitioning is the correct answer because it refers to the process of distributing rows of data into separate files. This technique is commonly used in database management systems to improve performance and scalability. By dividing the data horizontally, each partition can be stored and processed independently, allowing for parallel processing and reducing the load on individual servers. Horizontal partitioning is especially useful in scenarios where the dataset is too large to fit on a single server or when different parts of the data need to be accessed or modified separately.

Explanation

Horizontal partitioning is the correct answer because it refers to the process of distributing rows of data into separate files. This technique is commonly used in database management systems to improve performance and scalability. By dividing the data horizontally, each partition can be stored and processed independently, allowing for parallel processing and reducing the load on individual servers. Horizontal partitioning is especially useful in scenarios where the dataset is too large to fit on a single server or when different parts of the data need to be accessed or modified separately.

33. All of the following are common denormalization opportunities EXCEPT:

Two entities with a one-to-one relationship

A one-to-many relationship

A many-to-many relationship with nonkey attributes

Reference data

Denormalization is a technique used in database design to improve performance by adding redundant data to eliminate the need for complex joins. In a one-to-many relationship, there is already a natural redundancy as the "one" side can be repeated multiple times in the "many" side. Therefore, denormalizing this relationship would not provide any additional benefits. However, in a one-to-one relationship, a many-to-many relationship with nonkey attributes, or with reference data, denormalization can be beneficial as it can reduce the number of joins required and improve query performance.

Explanation

Denormalization is a technique used in database design to improve performance by adding redundant data to eliminate the need for complex joins. In a one-to-many relationship, there is already a natural redundancy as the "one" side can be repeated multiple times in the "many" side. Therefore, denormalizing this relationship would not provide any additional benefits. However, in a one-to-one relationship, a many-to-many relationship with nonkey attributes, or with reference data, denormalization can be beneficial as it can reduce the number of joins required and improve query performance.

34. START CH5 - A method to allow adjacent secondary memory space to contain rows from several tables is called:

Cluttering

Clustering

Concatenating

Compiling

Clustering is a method that allows adjacent secondary memory space to contain rows from several tables. It involves grouping similar data together based on certain criteria, such as common attributes or values. This helps improve data retrieval and processing efficiency by reducing the need to access multiple locations in secondary memory. Clustering can be particularly beneficial in database management systems where tables with related data can be physically stored close to each other, resulting in faster query execution and improved performance.

Explanation

Clustering is a method that allows adjacent secondary memory space to contain rows from several tables. It involves grouping similar data together based on certain criteria, such as common attributes or values. This helps improve data retrieval and processing efficiency by reducing the need to access multiple locations in secondary memory. Clustering can be particularly beneficial in database management systems where tables with related data can be physically stored close to each other, resulting in faster query execution and improved performance.

35. A type of join where a table is joined to itself is called a(n)

Unary join

Self join

Unnatural join

Pinned join

A self join is a type of join where a table is joined to itself. This is useful when we want to combine rows from the same table based on a related condition. In a self join, two instances of the same table are treated as separate entities, with different aliases assigned to them. This allows us to compare and match rows within the same table, enabling us to retrieve information that relates to each other.

Explanation

A self join is a type of join where a table is joined to itself. This is useful when we want to combine rows from the same table based on a related condition. In a self join, two instances of the same table are treated as separate entities, with different aliases assigned to them. This allows us to compare and match rows within the same table, enabling us to retrieve information that relates to each other.

36. Which of the following is not a new data type that were added in SQL:200n

BIGINT

BIT

MULTISET

XML

The data types BIGINT, MULTISET, and XML were all added in SQL:200n. However, BIT is not a new data type added in SQL:200n.

Explanation

The data types BIGINT, MULTISET, and XML were all added in SQL:200n. However, BIT is not a new data type added in SQL:200n.

37. The smallest unit of application data recognized by system software is a:

Field

Row

Data type

Column

A field is the smallest unit of application data recognized by system software. It refers to a single piece of information within a record or a database. For example, in a database table of student records, a field could represent the student's name, age, or ID number. Fields are used to organize and store data in a structured manner, allowing for efficient retrieval and manipulation of information.

Explanation

A field is the smallest unit of application data recognized by system software. It refers to a single piece of information within a record or a database. For example, in a database table of student records, a field could represent the student's name, age, or ID number. Fields are used to organize and store data in a structured manner, allowing for efficient retrieval and manipulation of information.

38. A _________ is a temporary table used in the FROM clause of an SQL query

Correlated subquery

Derived table

View table

None of the above

A derived table is a temporary table that is created within the query itself and used in the FROM clause. It is not a permanent table in the database but is derived from the result of a subquery or a combination of multiple tables. It allows for complex calculations and filtering to be performed on the data before it is used in the main query.

Explanation

A derived table is a temporary table that is created within the query itself and used in the FROM clause. It is not a permanent table in the database but is derived from the result of a subquery or a combination of multiple tables. It allows for complex calculations and filtering to be performed on the data before it is used in the main query.

39. IF-THEN-ELSE logical processing cannot be accomplished within an SQL statement

True

False

IF-THEN-ELSE logical processing can be accomplished within an SQL statement. SQL supports conditional logic through the use of CASE statements, which allow for conditional branching based on specific conditions. The CASE statement evaluates a series of conditions and returns a result based on the first condition that is met. Therefore, it is possible to perform IF-THEN-ELSE logical processing within an SQL statement using the CASE statement.

Explanation

IF-THEN-ELSE logical processing can be accomplished within an SQL statement. SQL supports conditional logic through the use of CASE statements, which allow for conditional branching based on specific conditions. The CASE statement evaluates a series of conditions and returns a result based on the first condition that is met. Therefore, it is possible to perform IF-THEN-ELSE logical processing within an SQL statement using the CASE statement.

40. An attribute (or attributes) that uniquely identifies each row in a relation is called a:

Column

Foreign field

Primary key

Duplicate key

A primary key is an attribute or set of attributes that uniquely identifies each row in a relation. It ensures that there are no duplicate values in the primary key column(s) and provides a way to uniquely identify and access each row in the table. This is essential for maintaining data integrity and for establishing relationships between tables in a database.

Explanation

A primary key is an attribute or set of attributes that uniquely identifies each row in a relation. It ensures that there are no duplicate values in the primary key column(s) and provides a way to uniquely identify and access each row in the table. This is essential for maintaining data integrity and for establishing relationships between tables in a database.

41. Embedded SQL consists of:

Hard coded SQL statements included in a program written in another language

SQL encapsulated inside of other SQL statments

SQL written into a front-end application

SQL translated to a lower-level language

Embedded SQL consists of hard coded SQL statements included in a program written in another language. This means that the SQL statements are directly written within the program code of another language, such as C++, Java, or Python. The SQL statements are not separate or independent, but rather integrated into the program itself. This allows for the program to interact with a database by executing these embedded SQL statements.

Explanation

Embedded SQL consists of hard coded SQL statements included in a program written in another language. This means that the SQL statements are directly written within the program code of another language, such as C++, Java, or Python. The SQL statements are not separate or independent, but rather integrated into the program itself. This allows for the program to interact with a database by executing these embedded SQL statements.

42. In SQL, a(n) _________ subquery is a type of subquery in which processing the inner query depends on data from the outer query

Correlated

Paired

Natural

Inner

A correlated subquery is a type of subquery in SQL where the processing of the inner query depends on data from the outer query. This means that the inner query is executed repeatedly for each row of the outer query, using values from the outer query to determine the result. This allows for a more dynamic and flexible query, as the inner query can be customized based on the values of each row in the outer query.

Explanation

A correlated subquery is a type of subquery in SQL where the processing of the inner query depends on data from the outer query. This means that the inner query is executed repeatedly for each row of the outer query, using values from the outer query to determine the result. This allows for a more dynamic and flexible query, as the inner query can be customized based on the values of each row in the outer query.

43. The entity integrity rule states that:

No primary key attribute can be null

Referential integrity must be maintained across all entities

Each entity must have a primary key

A primary key must have only one attribute

The entity integrity rule states that no primary key attribute can be null. This means that every entity in a database must have a primary key, and this primary key cannot have a null value. The primary key is used to uniquely identify each record in a table, and having a null primary key would mean that the record cannot be uniquely identified. Therefore, it is essential to ensure that the primary key attribute is always populated with a non-null value.

Explanation

The entity integrity rule states that no primary key attribute can be null. This means that every entity in a database must have a primary key, and this primary key cannot have a null value. The primary key is used to uniquely identify each record in a table, and having a null primary key would mean that the record cannot be uniquely identified. Therefore, it is essential to ensure that the primary key attribute is always populated with a non-null value.

44. One disadvantage of partitioning is:

Simplicity

Remote optimization

Extra space and update time

Shorter technology spans

Partitioning in this context refers to dividing a system or database into smaller sections or partitions. One disadvantage of partitioning is that it requires extra space and update time. Partitioning involves creating separate storage spaces for different partitions, which can lead to increased storage requirements. Additionally, when updates or changes are made to the system, it may take longer to update each partition individually, resulting in increased update time. Therefore, the extra space and update time required are considered as a disadvantage of partitioning.

Explanation

Partitioning in this context refers to dividing a system or database into smaller sections or partitions. One disadvantage of partitioning is that it requires extra space and update time. Partitioning involves creating separate storage spaces for different partitions, which can lead to increased storage requirements. Additionally, when updates or changes are made to the system, it may take longer to update each partition individually, resulting in increased update time. Therefore, the extra space and update time required are considered as a disadvantage of partitioning.

45. Sensitivity testing involves:

Checking if data is allergic

Seeing how accurate data are

Checking to see if missing data will greatly impact results

None of the above

Sensitivity testing involves checking to see if missing data will greatly impact results. This means that sensitivity testing is done to assess the impact of missing data on the accuracy and reliability of the results. By conducting sensitivity testing, researchers can determine the extent to which missing data can affect the validity of the findings and make necessary adjustments or considerations to ensure the accuracy of the analysis.

Explanation

Sensitivity testing involves checking to see if missing data will greatly impact results. This means that sensitivity testing is done to assess the impact of missing data on the accuracy and reliability of the results. By conducting sensitivity testing, researchers can determine the extent to which missing data can affect the validity of the findings and make necessary adjustments or considerations to ensure the accuracy of the analysis.

46. A rule that states that each foreign key value must match a primary key value in the other

Referential integrity constraint

Key match rule

Entity key group rule

Foreign/primary match rule

The explanation for the correct answer is that a referential integrity constraint is a rule that ensures that each foreign key value in a table must match a primary key value in another table. This constraint helps maintain the integrity and consistency of the data by preventing orphaned records or invalid references. It enforces the relationship between tables and ensures that the data remains accurate and valid.

Explanation

The explanation for the correct answer is that a referential integrity constraint is a rule that ensures that each foreign key value in a table must match a primary key value in another table. This constraint helps maintain the integrity and consistency of the data by preventing orphaned records or invalid references. It enforces the relationship between tables and ensures that the data remains accurate and valid.

47. All of the following are valid datatypes in Oracle 11g EXCEPT

Varchar2

Datetime

Blob

Number

In Oracle 11g, the valid datatypes include varchar2, blob, and number. However, datetime is not a valid datatype in Oracle 11g.

Explanation

In Oracle 11g, the valid datatypes include varchar2, blob, and number. However, datetime is not a valid datatype in Oracle 11g.

48. A key decision in the physical design process is:

Knowing the user base

Selecting structures

Deciding on the monitor

All of the above

In the physical design process, selecting structures is a key decision because it determines the overall layout and organization of the physical components. The structures chosen will impact the efficiency, performance, and scalability of the design. By carefully selecting structures, designers can ensure that the system meets the required functionality and performance goals. This decision involves considering factors such as the type of data being processed, the relationships between different components, and the specific requirements of the system.

Explanation

In the physical design process, selecting structures is a key decision because it determines the overall layout and organization of the physical components. The structures chosen will impact the efficiency, performance, and scalability of the design. By carefully selecting structures, designers can ensure that the system meets the required functionality and performance goals. This decision involves considering factors such as the type of data being processed, the relationships between different components, and the specific requirements of the system.

49. All of the following are guidelines for better query design EXCEPT:

Understand how indexes are used in query processing

Use a lot of self-joins

Write simple queries

Retrieve on the data that you need

The given answer is "use a lot of self-joins." This means that using a lot of self-joins is not a guideline for better query design. Self-joins are used to join a table with itself, and while they can be useful in certain cases, using them excessively can lead to complex and inefficient queries. Therefore, it is recommended to avoid using a lot of self-joins in order to improve query performance and maintain simplicity.

Explanation

The given answer is "use a lot of self-joins." This means that using a lot of self-joins is not a guideline for better query design. Self-joins are used to join a table with itself, and while they can be useful in certain cases, using them excessively can lead to complex and inefficient queries. Therefore, it is recommended to avoid using a lot of self-joins in order to improve query performance and maintain simplicity.

50. An attribute that may have more than one meaning is called a(n):

Homonym

Alias

Double defined attribute

Synonym

A homonym is a word that has multiple meanings. In the context of this question, an attribute that may have more than one meaning is referred to as a homonym. This means that the attribute can be interpreted or understood in different ways, leading to potential confusion or ambiguity.

Explanation

A homonym is a word that has multiple meanings. In the context of this question, an attribute that may have more than one meaning is referred to as a homonym. This means that the attribute can be interpreted or understood in different ways, leading to potential confusion or ambiguity.

51. An attribute in a relation of a database that serves as the primary key of another relation in the same database is called a:

Link attribute

Link key

Foreign key

Foreign attribute

A foreign key is an attribute in a relation of a database that serves as the primary key of another relation in the same database. It is used to establish a relationship between two tables in a database by referencing the primary key of one table as a foreign key in another table. This allows for the creation of a link between the two tables and enables the enforcement of referential integrity, ensuring that the data in the foreign key column matches the data in the primary key column it references.

Explanation

A foreign key is an attribute in a relation of a database that serves as the primary key of another relation in the same database. It is used to establish a relationship between two tables in a database by referencing the primary key of one table as a foreign key in another table. This allows for the creation of a link between the two tables and enables the enforcement of referential integrity, ensuring that the data in the foreign key column matches the data in the primary key column it references.

52. Physical database design decisions must be made carefully because of impacts on:

Data accessibility

Response times

Security

All of the above

Physical database design decisions must be made carefully because they have impacts on data accessibility, response times, and security. Data accessibility refers to the ability to retrieve and manipulate data efficiently, which can be affected by the physical design choices. Response times, or the speed at which the database responds to user queries, can also be influenced by the physical design. Additionally, security measures such as encryption, access controls, and backup strategies must be considered during the physical design process to protect the data from unauthorized access or loss. Therefore, all of the mentioned factors are impacted by physical database design decisions.

Explanation

Physical database design decisions must be made carefully because they have impacts on data accessibility, response times, and security. Data accessibility refers to the ability to retrieve and manipulate data efficiently, which can be affected by the physical design choices. Response times, or the speed at which the database responds to user queries, can also be influenced by the physical design. Additionally, security measures such as encryption, access controls, and backup strategies must be considered during the physical design process to protect the data from unauthorized access or loss. Therefore, all of the mentioned factors are impacted by physical database design decisions.

53. In which of the following situations would one have to use an outer join in order to obtain the desired results?

A report is desired that lists all customers who placed an order

A report is desired that lists all customers and the total of their orders

There is never a situation that requires only an outer join

In this situation, an outer join would be required to obtain the desired results because it includes customers who did not place an order during the most recent month. An outer join allows for the combination of data from two tables, in this case the customers table and the orders table, even if there is no matching data in the orders table. This ensures that all customers are included in the report, regardless of whether they placed an order or not during the most recent month.

Explanation

In this situation, an outer join would be required to obtain the desired results because it includes customers who did not place an order during the most recent month. An outer join allows for the combination of data from two tables, in this case the customers table and the orders table, even if there is no matching data in the orders table. This ensures that all customers are included in the report, regardless of whether they placed an order or not during the most recent month.

54. A relation that contains no multivalued attributes, and has nonkey attributes solely dependent on the primary key, but contains transitive dependencies is in which normal form?

First

Second

Third

Fourth

The given question is asking about the normal form of a relation that has no multivalued attributes, nonkey attributes solely dependent on the primary key, but contains transitive dependencies. The correct answer is "Second." Second normal form (2NF) states that a relation should be in first normal form (1NF) and all nonkey attributes should be fully dependent on the primary key. In this case, the relation meets the criteria for 2NF because it has no multivalued attributes and the nonkey attributes are solely dependent on the primary key. However, it still contains transitive dependencies, which means that some nonkey attributes are dependent on other nonkey attributes.

Explanation

The given question is asking about the normal form of a relation that has no multivalued attributes, nonkey attributes solely dependent on the primary key, but contains transitive dependencies. The correct answer is "Second." Second normal form (2NF) states that a relation should be in first normal form (1NF) and all nonkey attributes should be fully dependent on the primary key. In this case, the relation meets the criteria for 2NF because it has no multivalued attributes and the nonkey attributes are solely dependent on the primary key. However, it still contains transitive dependencies, which means that some nonkey attributes are dependent on other nonkey attributes.

55. RANK and DENSE-RANK are examples of:

Ceilings

Door functions

Window functions

Moving functions

RANK and DENSE-RANK are examples of window functions. Window functions are used to perform calculations across a set of rows that are related to the current row. They allow us to partition the data into smaller groups and perform calculations within each group. RANK and DENSE-RANK specifically assign a unique rank or dense rank to each row based on a specified order.

Explanation

RANK and DENSE-RANK are examples of window functions. Window functions are used to perform calculations across a set of rows that are related to the current row. They allow us to partition the data into smaller groups and perform calculations within each group. RANK and DENSE-RANK specifically assign a unique rank or dense rank to each row based on a specified order.

56. A method for handling missing data is to:

Substitute and estimate for the missing data

Track missing data with special reports

Perform sensitivity testing

All of the above

The correct answer is "all of the above" because each of the options mentioned - substituting and estimating for the missing data, tracking missing data with special reports, and performing sensitivity testing - are valid methods for handling missing data. By using a combination of these approaches, one can effectively address the issue of missing data and ensure that it does not significantly impact the overall analysis or results.

Explanation

The correct answer is "all of the above" because each of the options mentioned - substituting and estimating for the missing data, tracking missing data with special reports, and performing sensitivity testing - are valid methods for handling missing data. By using a combination of these approaches, one can effectively address the issue of missing data and ensure that it does not significantly impact the overall analysis or results.

57. Two or more attributes having different names but the same meaning are called:

Homonyms

Aliases

Synonyms

Alternate attributes

Synonyms are two or more attributes that have different names but the same meaning. In other words, they are different terms used to describe the same concept or attribute. For example, "car" and "automobile" are synonyms as they both refer to the same object. Similarly, in the context of databases, synonyms can be used to refer to different attribute names that represent the same underlying data.

Explanation

Synonyms are two or more attributes that have different names but the same meaning. In other words, they are different terms used to describe the same concept or attribute. For example, "car" and "automobile" are synonyms as they both refer to the same object. Similarly, in the context of databases, synonyms can be used to refer to different attribute names that represent the same underlying data.

58. A candidate key must satisfy all of the following conditions EXCEPT:

The key must uniquely identify the row

The key must indicate the rows position in the table

The key must be nonredundant

Each nonkey attribute is functionally dependent upon it

A candidate key is a unique identifier for a row in a table. It must satisfy the conditions of being nonredundant, ensuring that each nonkey attribute is functionally dependent upon it, and uniquely identifying the row. However, it does not need to indicate the row's position in the table. The position of a row in a table is typically determined by the order in which it was inserted, but it is not a requirement for a candidate key.

Explanation

A candidate key is a unique identifier for a row in a table. It must satisfy the conditions of being nonredundant, ensuring that each nonkey attribute is functionally dependent upon it, and uniquely identifying the row. However, it does not need to indicate the row's position in the table. The position of a row in a table is typically determined by the order in which it was inserted, but it is not a requirement for a candidate key.

59. All of the following are the main goals of normalization EXCEPT:

Minimize data redundancy

Simplify the enforcement of referential integrity

Maximize storage space

Make it easier to maintain data

Normalization is a database design technique that aims to minimize data redundancy and improve data integrity. It simplifies the enforcement of referential integrity by ensuring that relationships between tables are properly defined and maintained. It also makes it easier to maintain data by organizing it into smaller, more manageable tables. However, maximizing storage space is not a goal of normalization. Instead, normalization focuses on optimizing data structure and reducing duplication to improve efficiency and maintainability.

Explanation

Normalization is a database design technique that aims to minimize data redundancy and improve data integrity. It simplifies the enforcement of referential integrity by ensuring that relationships between tables are properly defined and maintained. It also makes it easier to maintain data by organizing it into smaller, more manageable tables. However, maximizing storage space is not a goal of normalization. Instead, normalization focuses on optimizing data structure and reducing duplication to improve efficiency and maintainability.

60. When a regular entity type contains a multivalued attribute, one must:

Create a single relation with multiple lines for each instance of the multivalued attribute

Create two new relations, one containing the multivalued attribute

Create two new relations, both containing the multivalued attribute

None of the above

When a regular entity type contains a multivalued attribute, creating two new relations, one containing the multivalued attribute, is the correct approach. This is because a multivalued attribute cannot be represented in a single relation with multiple lines for each instance of the attribute. Instead, it requires a separate relation to properly capture the multiple values. Therefore, the option of creating two new relations, one containing the multivalued attribute, is the appropriate solution in this scenario.

Explanation

When a regular entity type contains a multivalued attribute, creating two new relations, one containing the multivalued attribute, is the correct approach. This is because a multivalued attribute cannot be represented in a single relation with multiple lines for each instance of the attribute. Instead, it requires a separate relation to properly capture the multiple values. Therefore, the option of creating two new relations, one containing the multivalued attribute, is the appropriate solution in this scenario.

61. ________________ is a component of the relational data model included to specify business rules to maintain the integrity of data when they are manipulated.

Business rule constraint

Data integrity

Business integrity

Data structure

Data integrity is a component of the relational data model that ensures the accuracy, consistency, and reliability of data. It specifies the rules and constraints that need to be followed when manipulating data to maintain its integrity. These rules can include constraints such as primary key uniqueness, foreign key relationships, and data validation rules. By enforcing data integrity, organizations can ensure that their data remains reliable and consistent, thereby improving the overall quality and trustworthiness of their data.

Explanation

Data integrity is a component of the relational data model that ensures the accuracy, consistency, and reliability of data. It specifies the rules and constraints that need to be followed when manipulating data to maintain its integrity. These rules can include constraints such as primary key uniqueness, foreign key relationships, and data validation rules. By enforcing data integrity, organizations can ensure that their data remains reliable and consistent, thereby improving the overall quality and trustworthiness of their data.

62. Another form of demornalization where the same data are stored in multiple places in the database is called:

Data duplication

Data replication

Advanced placement

Horizaontal partitioning

Data replication refers to the practice of storing the same data in multiple places within a database. This is done to improve data availability, reliability, and performance. By duplicating data, it becomes possible to access it from different locations, reducing the risk of data loss and ensuring that the system can continue to function even if one copy of the data becomes unavailable. Data replication is commonly used in distributed databases and systems that require high levels of data availability and fault tolerance.

Explanation

Data replication refers to the practice of storing the same data in multiple places within a database. This is done to improve data availability, reliability, and performance. By duplicating data, it becomes possible to access it from different locations, reducing the risk of data loss and ensuring that the system can continue to function even if one copy of the data becomes unavailable. Data replication is commonly used in distributed databases and systems that require high levels of data availability and fault tolerance.

63. Extensions defined in SQL-99 that include the capability to create and drop modules of code stored in the database schema across user sessions are called:

Stored procedures

Persistent stored modules

Flow control modules

None of the above

Persistent stored modules are extensions defined in SQL-99 that allow the creation and deletion of code modules stored in the database schema across multiple user sessions. These modules are designed to persist in the database and can be accessed and executed by different users at different times. This capability provides a way to store and manage reusable code within the database, enhancing code organization and promoting code reusability.

Explanation

Persistent stored modules are extensions defined in SQL-99 that allow the creation and deletion of code modules stored in the database schema across multiple user sessions. These modules are designed to persist in the database and can be accessed and executed by different users at different times. This capability provides a way to store and manage reusable code within the database, enhancing code organization and promoting code reusability.

64. An understanding of how to merge relation is important because:

A) there may be a need to merge relations on projects with subteams

Different views may be integrated

New data requirements may produce new relations to be merged

All of the above

An understanding of how to merge relations is important because there may be a need to merge relations on projects with subteams, different views may need to be integrated, and new data requirements may produce new relations that need to be merged.

Explanation

An understanding of how to merge relations is important because there may be a need to merge relations on projects with subteams, different views may need to be integrated, and new data requirements may produce new relations that need to be merged.

65. Which of the following anomalies result from a transitive dependency?

Insertion

Modification

Deletion

All of the above

A transitive dependency is a relationship between three or more attributes in a database table, where the value of one attribute determines the value of another attribute indirectly. In this case, all of the given anomalies (insertion, modification, and deletion) can occur as a result of a transitive dependency. When a transitive dependency exists, inserting, modifying, or deleting a value in one attribute can cause inconsistencies or errors in the related attributes. Therefore, all of the mentioned anomalies can be caused by a transitive dependency.

Explanation

A transitive dependency is a relationship between three or more attributes in a database table, where the value of one attribute determines the value of another attribute indirectly. In this case, all of the given anomalies (insertion, modification, and deletion) can occur as a result of a transitive dependency. When a transitive dependency exists, inserting, modifying, or deleting a value in one attribute can cause inconsistencies or errors in the related attributes. Therefore, all of the mentioned anomalies can be caused by a transitive dependency.

66. Horizontal partitioning makes sense:

When different categories of a table's rows are processed seperately

When less security is needed

When partitions must be orgranized the same

When all of the above are true

Horizontal partitioning makes sense when different categories of a table's rows are processed separately. This means that the rows of the table are divided into separate partitions based on specific categories or criteria. By doing so, it becomes easier to perform operations or queries on specific categories of data without affecting the entire table. This can improve performance and efficiency in situations where different categories of data require different processing or analysis.

Explanation

Horizontal partitioning makes sense when different categories of a table's rows are processed separately. This means that the rows of the table are divided into separate partitions based on specific categories or criteria. By doing so, it becomes easier to perform operations or queries on specific categories of data without affecting the entire table. This can improve performance and efficiency in situations where different categories of data require different processing or analysis.

67. A procedure is:

Stored within the databse

Given a unique name

Called by name

All of the above

A procedure refers to a set of instructions or operations that are stored within a database. It is given a unique name to identify and distinguish it from other procedures. These procedures are called by their respective names to execute the instructions they contain. Therefore, the correct answer is "all of the above" as all the statements mentioned - being stored within the database, having a unique name, and being called by name - are true for a procedure.

Explanation

A procedure refers to a set of instructions or operations that are stored within a database. It is given a unique name to identify and distinguish it from other procedures. These procedures are called by their respective names to execute the instructions they contain. Therefore, the correct answer is "all of the above" as all the statements mentioned - being stored within the database, having a unique name, and being called by name - are true for a procedure.

68. In order for two quieries to be UNION-compatible, they must:

Both have the same number of lines in their SQL statements

Both output compatible data types for each column and return the same number of rows

Both return at least one row

All of the above

For two queries to be UNION-compatible, they must both output compatible data types for each column and return the same number of rows. This means that the columns in both queries should have the same data types and the number of rows returned by each query should be equal. This ensures that the result of the UNION operation will have consistent data types and a predictable number of rows.

Explanation

For two queries to be UNION-compatible, they must both output compatible data types for each column and return the same number of rows. This means that the columns in both queries should have the same data types and the number of rows returned by each query should be equal. This ensures that the result of the UNION operation will have consistent data types and a predictable number of rows.

69. Which of the following is an objective of selecting a data type?

Represent a small number of possible values

Maximize storage space

Limit security

Improve data integrity

Selecting a data type helps improve data integrity by ensuring that the data is stored and processed correctly. By choosing the appropriate data type, data can be validated and constraints can be applied to prevent incorrect or inconsistent data from being entered. This helps in maintaining the accuracy and reliability of the data, reducing errors and improving overall data quality.

Explanation

Selecting a data type helps improve data integrity by ensuring that the data is stored and processed correctly. By choosing the appropriate data type, data can be validated and constraints can be applied to prevent incorrect or inconsistent data from being entered. This helps in maintaining the accuracy and reliability of the data, reducing errors and improving overall data quality.

70. The UNION clause is used to:

Combine the output from multiple queries into a single result table

Join two tables together to form one table

Find all rows that do not match in two tables

None of the above

The UNION clause is used to combine the output from multiple queries into a single result table. This means that it allows you to retrieve data from multiple tables or queries and display the results as if they came from a single table. By using the UNION clause, you can merge the rows returned by each query and eliminate duplicates, resulting in a unified and comprehensive result set.

Explanation

The UNION clause is used to combine the output from multiple queries into a single result table. This means that it allows you to retrieve data from multiple tables or queries and display the results as if they came from a single table. By using the UNION clause, you can merge the rows returned by each query and eliminate duplicates, resulting in a unified and comprehensive result set.

71. If the DBA wishes to describe all tables in the database, which data dictionary view should be accessed in Oracle?

DBA_tab_privs

DBA_tab_comments

DBA_table_label

DBA_tables

The correct answer is DBA_tables. This data dictionary view in Oracle contains information about all tables in the database. It includes details such as table names, owner names, number of rows, and table creation and modification timestamps. By accessing this view, the DBA can obtain a comprehensive description of all tables in the database.

Explanation

The correct answer is DBA_tables. This data dictionary view in Oracle contains information about all tables in the database. It includes details such as table names, owner names, number of rows, and table creation and modification timestamps. By accessing this view, the DBA can obtain a comprehensive description of all tables in the database.

72. The relational data model consists of which components?

Data structure

Data manipulation

Data integrity

All of the above

The relational data model consists of all of the mentioned components: data structure, data manipulation, and data integrity. Data structure refers to the organization and format of the data stored in tables. Data manipulation involves operations such as inserting, updating, and deleting data in the tables. Data integrity ensures that the data is accurate, consistent, and follows predefined rules or constraints. Therefore, all of these components are essential in the relational data model.

Explanation

The relational data model consists of all of the mentioned components: data structure, data manipulation, and data integrity. Data structure refers to the organization and format of the data stored in tables. Data manipulation involves operations such as inserting, updating, and deleting data in the tables. Data integrity ensures that the data is accurate, consistent, and follows predefined rules or constraints. Therefore, all of these components are essential in the relational data model.

73. A(n) _______________ is a routine that converts a primary key value into a relative record number.

Record index calculator

Index pointer program

Hashing algorithm

Pointing algorithm

A hashing algorithm is a routine that converts a primary key value into a relative record number. It uses a mathematical function to map the key value to a specific location in a data structure, such as a hash table. This allows for efficient retrieval and storage of records based on their primary key values.

Explanation

A hashing algorithm is a routine that converts a primary key value into a relative record number. It uses a mathematical function to map the key value to a specific location in a data structure, such as a hash table. This allows for efficient retrieval and storage of records based on their primary key values.

74. CH -4 A nonkey attribute is also called a(n)

Column

Unimportant datum

Descriptor

Address

A nonkey attribute is also called a descriptor because it provides additional information about an entity but does not play a role in identifying or distinguishing that entity. It is not a critical piece of data in the database and does not contribute to the primary key or any unique identifier. Instead, it helps to describe or provide details about the entity.

Explanation

A nonkey attribute is also called a descriptor because it provides additional information about an entity but does not play a role in identifying or distinguishing that entity. It is not a critical piece of data in the database and does not contribute to the primary key or any unique identifier. Instead, it helps to describe or provide details about the entity.

75. Which of the following are anomalies that can be caused by redundancies in tables

Insertion

Deletion

Modification

All of the above

Redundancies in tables can lead to anomalies such as insertion anomalies, deletion anomalies, and modification anomalies. Insertion anomalies occur when it is not possible to insert certain data into the table without also inserting unrelated data. Deletion anomalies occur when deleting certain data also results in the unintentional loss of other related data. Modification anomalies occur when updating certain data requires making changes in multiple places, leading to inconsistencies. Therefore, all of the options mentioned (insertion, deletion, and modification) can be caused by redundancies in tables.

Explanation

Redundancies in tables can lead to anomalies such as insertion anomalies, deletion anomalies, and modification anomalies. Insertion anomalies occur when it is not possible to insert certain data into the table without also inserting unrelated data. Deletion anomalies occur when deleting certain data also results in the unintentional loss of other related data. Modification anomalies occur when updating certain data requires making changes in multiple places, leading to inconsistencies. Therefore, all of the options mentioned (insertion, deletion, and modification) can be caused by redundancies in tables.

76. LAST CH 4 A form of database specification that indicates all the parameters for data storage that are then input to database implementation is:

Logical

Physical

Schematic

Conceptual

The correct answer is "physical". In database specification, the physical level focuses on the actual implementation of the database and includes details such as file organization, indexing methods, and storage structures. It specifies how the data is physically stored on the storage medium. Logical and conceptual levels deal with the logical organization and structure of the database, while the schematic level focuses on the design and organization of individual database components.

Explanation

The correct answer is "physical". In database specification, the physical level focuses on the actual implementation of the database and includes details such as file organization, indexing methods, and storage structures. It specifies how the data is physically stored on the storage medium. Logical and conceptual levels deal with the logical organization and structure of the database, while the schematic level focuses on the design and organization of individual database components.

77. ___________ takes a value of true if a subquery returns an intermediate results table which contains one or more rows

IN

HAVING

EXISTS

EXTENTS

The EXISTS operator takes a value of true if a subquery returns an intermediate results table which contains one or more rows. It is used to check for the existence of rows in a subquery and can be used in the WHERE clause of a SQL statement.

Explanation

The EXISTS operator takes a value of true if a subquery returns an intermediate results table which contains one or more rows. It is used to check for the existence of rows in a subquery and can be used in the WHERE clause of a SQL statement.

78. One major disadvantage of the outer join is that information is easily lost

True

False

The given statement is false. The outer join does not easily lose information. In an outer join, all the rows from one table are included, even if there is no matching row in the other table. This ensures that no information is lost. Therefore, the statement is incorrect.

Explanation

The given statement is false. The outer join does not easily lose information. In an outer join, all the rows from one table are included, even if there is no matching row in the other table. This ensures that no information is lost. Therefore, the statement is incorrect.

79. A file organization that uses hashing to map a key into a location in an index where there is a pointer to the actual data record matching the hash key is called a:

Hashed file organization

Hash key

Multi-indexed file organization

Hash index table

A file organization that uses hashing to map a key into a location in an index where there is a pointer to the actual data record matching the hash key is called a hash index table. This type of file organization utilizes a hash function to generate a unique index for each key, allowing for efficient retrieval of data records by directly accessing the index table. The index table contains pointers to the actual data records, enabling quick and direct access to the desired data based on the hash key.

Explanation

A file organization that uses hashing to map a key into a location in an index where there is a pointer to the actual data record matching the hash key is called a hash index table. This type of file organization utilizes a hash function to generate a unique index for each key, allowing for efficient retrieval of data records by directly accessing the index table. The index table contains pointers to the actual data records, enabling quick and direct access to the desired data based on the hash key.

80. User-defined data types:

Can be a subclass of a standard type

Can behave as an object

Can have defined functions and methods

All of the above

User-defined data types can be a subclass of a standard type, meaning that they can inherit properties and behaviors from existing data types. They can also behave as an object, allowing them to have their own attributes and methods. Additionally, user-defined data types can have defined functions and methods, allowing for custom behavior and functionality. Therefore, the correct answer is "all of the above" as all the given statements are true.

Explanation

User-defined data types can be a subclass of a standard type, meaning that they can inherit properties and behaviors from existing data types. They can also behave as an object, allowing them to have their own attributes and methods. Additionally, user-defined data types can have defined functions and methods, allowing for custom behavior and functionality. Therefore, the correct answer is "all of the above" as all the given statements are true.

81. Transaction integrity commands are not used to identify whole units of database changes that must be completed in full for the database to retain integrity

True

False

Transaction integrity commands are actually used to identify whole units of database changes that must be completed in full for the database to retain integrity. These commands ensure that all changes made within a transaction are either committed or rolled back as a single unit, preventing partial updates and maintaining the consistency and integrity of the database. Therefore, the correct answer is False.

Explanation

Transaction integrity commands are actually used to identify whole units of database changes that must be completed in full for the database to retain integrity. These commands ensure that all changes made within a transaction are either committed or rolled back as a single unit, preventing partial updates and maintaining the consistency and integrity of the database. Therefore, the correct answer is False.

82. An equi-join is a join in which one of the duplicate columns is eliminated in the result table

True

False

An equi-join is a type of join where the equality condition is applied on two or more columns from different tables. It returns rows that have matching values in the specified columns. In an equi-join, duplicate columns are not eliminated in the result table. Instead, all columns from the joined tables are included in the result, including any duplicate columns. Therefore, the given statement that an equi-join eliminates one of the duplicate columns in the result table is false.

Explanation

An equi-join is a type of join where the equality condition is applied on two or more columns from different tables. It returns rows that have matching values in the specified columns. In an equi-join, duplicate columns are not eliminated in the result table. Instead, all columns from the joined tables are included in the result, including any duplicate columns. Therefore, the given statement that an equi-join eliminates one of the duplicate columns in the result table is false.

83. A detailed coding scheme recognized by system software for representing organization data is called a(n):

DBMS code

Data type

SQL

DB layouts

A data type is a detailed coding scheme recognized by system software for representing organization data. It defines the kind of data that can be stored, the operations that can be performed on it, and the way it is stored in memory. Data types help ensure data integrity and facilitate efficient storage and retrieval of data in a database management system (DBMS). SQL is a language used to communicate with DBMS, while DB layouts refer to the arrangement of data in a database. Therefore, the correct answer is data type.

Explanation

A data type is a detailed coding scheme recognized by system software for representing organization data. It defines the kind of data that can be stored, the operations that can be performed on it, and the way it is stored in memory. Data types help ensure data integrity and facilitate efficient storage and retrieval of data in a database management system (DBMS). SQL is a language used to communicate with DBMS, while DB layouts refer to the arrangement of data in a database. Therefore, the correct answer is data type.

84. The storage format for each attribute from the logical data model is chosen to maximize _________________ and minimize storage space

Query design

Programmer productivity

Data integrity

Data integration

The storage format for each attribute from the logical data model is chosen to maximize data integrity and minimize storage space. Data integrity refers to the accuracy, consistency, and reliability of data, and by choosing the appropriate storage format, the data can be stored in a way that ensures its integrity. Additionally, minimizing storage space is important to optimize storage resources and reduce costs. Therefore, selecting a storage format that maximizes data integrity and minimizes storage space is crucial for maintaining reliable and efficient data storage.

Explanation

The storage format for each attribute from the logical data model is chosen to maximize data integrity and minimize storage space. Data integrity refers to the accuracy, consistency, and reliability of data, and by choosing the appropriate storage format, the data can be stored in a way that ensures its integrity. Additionally, minimizing storage space is important to optimize storage resources and reduce costs. Therefore, selecting a storage format that maximizes data integrity and minimizes storage space is crucial for maintaining reliable and efficient data storage.

85. END CH5 - A requirement to begin designing physical files and databases is:

Normalized relaions

Definitions of each attribute

Technology descriptions

All of the above

To begin designing physical files and databases, it is necessary to have normalized relations, which ensure that the data is organized efficiently and avoids data redundancy. Additionally, definitions of each attribute are required to provide a clear understanding of the data elements and their characteristics. Technology descriptions are also essential as they outline the specific tools and technologies that will be used in the design and implementation process. Therefore, all of these components are necessary to successfully start the design of physical files and databases.

Explanation

To begin designing physical files and databases, it is necessary to have normalized relations, which ensure that the data is organized efficiently and avoids data redundancy. Additionally, definitions of each attribute are required to provide a clear understanding of the data elements and their characteristics. Technology descriptions are also essential as they outline the specific tools and technologies that will be used in the design and implementation process. Therefore, all of these components are necessary to successfully start the design of physical files and databases.

86. One major advantage of the outer join is that:

Information is easily accessible

Information is not lost

The query is easier to write

All of the above

The correct answer is "information is not lost". This is because in an outer join, all the rows from one table are included in the result set, even if there is no matching row in the other table. This ensures that no information is lost during the join operation.

Explanation

The correct answer is "information is not lost". This is because in an outer join, all the rows from one table are included in the result set, even if there is no matching row in the other table. This ensures that no information is lost during the join operation.

87. In order to embed SQL inside of another language, the __________ statement must be placed before the SQL in the host language

GET SQL

EXEC SQL

RUN SQL

SQL SQL

To embed SQL inside of another language, the "EXEC SQL" statement must be placed before the SQL in the host language. This statement signals the host language that the following code is SQL and needs to be executed accordingly. By using "EXEC SQL" before the SQL code, the host language can properly interpret and execute the SQL statements.

Explanation

To embed SQL inside of another language, the "EXEC SQL" statement must be placed before the SQL in the host language. This statement signals the host language that the following code is SQL and needs to be executed accordingly. By using "EXEC SQL" before the SQL code, the host language can properly interpret and execute the SQL statements.

88. In which data model would a code table appear

Conceptual

Logical

Physical

Data layout

A code table would appear in the physical data model. The physical data model represents the actual implementation of the database and includes details such as data types, indexes, and storage structures. Code tables are used to store codes or values that are frequently used in the database, such as status codes or category codes. They provide a standardized and efficient way to store and retrieve these values, making them an important component of the physical data model.

Explanation

A code table would appear in the physical data model. The physical data model represents the actual implementation of the database and includes details such as data types, indexes, and storage structures. Code tables are used to store codes or values that are frequently used in the database, such as status codes or category codes. They provide a standardized and efficient way to store and retrieve these values, making them an important component of the physical data model.

89. A type of join implemented in SQL-1999 and by extension SQL-2003 that returns all of the data from each table that is joined is called a(n)

Outer join

Inner join

Union join

Intersect join

An outer join is a type of join implemented in SQL-1999 and by extension SQL-2003 that returns all of the data from each table that is joined. In an outer join, if there is no match between the tables on the join condition, null values are returned for the columns of the table that does not have a match. This allows for the inclusion of unmatched rows from both tables in the result set. A union join, on the other hand, is not a valid type of join in SQL.

Explanation

An outer join is a type of join implemented in SQL-1999 and by extension SQL-2003 that returns all of the data from each table that is joined. In an outer join, if there is no match between the tables on the join condition, null values are returned for the columns of the table that does not have a match. This allows for the inclusion of unmatched rows from both tables in the result set. A union join, on the other hand, is not a valid type of join in SQL.

90. A primary key whose value is unique across all relations is called a(n):

Global primary key

Inter-table primary key

Enterprise key

Foreign global key

An enterprise key is a primary key that is unique across all relations in a database. This means that no other relation within the database can have the same value for this key. It is used to uniquely identify records across multiple tables in the entire enterprise system. This ensures data integrity and consistency throughout the database, allowing for efficient data retrieval and manipulation.

Explanation

An enterprise key is a primary key that is unique across all relations in a database. This means that no other relation within the database can have the same value for this key. It is used to uniquely identify records across multiple tables in the entire enterprise system. This ensures data integrity and consistency throughout the database, allowing for efficient data retrieval and manipulation.

91. The most commonly used form of join operation is the:

Outer join

Union join

Equi-join

Natural join

The natural join is the most commonly used form of join operation. It combines rows from two tables based on matching values in their common columns. It returns only the rows where the values in the common columns match in both tables. This type of join is useful when you want to combine data from two tables that have a common attribute. It eliminates the need to specify the join condition explicitly, as it automatically matches the columns with the same name in both tables.

Explanation

The natural join is the most commonly used form of join operation. It combines rows from two tables based on matching values in their common columns. It returns only the rows where the values in the common columns match in both tables. This type of join is useful when you want to combine data from two tables that have a common attribute. It eliminates the need to specify the join condition explicitly, as it automatically matches the columns with the same name in both tables.

92. Which of the following are properties of relations

Each attribute has a unique name

No two rows in a relation are identical

There are no multivalued attributes are in a relation

All of the above

All of the given options are properties of relations. In a relation, each attribute must have a unique name to identify it uniquely. Additionally, no two rows in a relation can be identical, as each row represents a unique tuple. Lastly, relations in a database do not allow multivalued attributes, meaning that each attribute in a relation can have only a single value. Therefore, all of the given options are correct properties of relations.

Explanation

All of the given options are properties of relations. In a relation, each attribute must have a unique name to identify it uniquely. Additionally, no two rows in a relation can be identical, as each row represents a unique tuple. Lastly, relations in a database do not allow multivalued attributes, meaning that each attribute in a relation can have only a single value. Therefore, all of the given options are correct properties of relations.

93. There is a special operation in SQL to join a table to itself

True

False

In SQL, there is no special operation to join a table to itself. However, it is possible to achieve self-joins by using aliases to create multiple references to the same table within the query. This allows for comparisons and matching of rows within the same table, but it is not a distinct operation specifically designed for self-joining. Therefore, the correct answer is false.

Explanation

In SQL, there is no special operation to join a table to itself. However, it is possible to achieve self-joins by using aliases to create multiple references to the same table within the query. This allows for comparisons and matching of rows within the same table, but it is not a distinct operation specifically designed for self-joining. Therefore, the correct answer is false.

94. One advantage of partitioning is:

Efficiency

Remote optimization

Extra space and update time

Both A and B

Partitioning provides the advantage of efficiency. By dividing a larger problem or dataset into smaller, more manageable parts, partitioning allows for parallel processing and distributed computing. This can significantly improve the overall efficiency of a system or algorithm, as multiple tasks can be executed simultaneously. Additionally, partitioning can help optimize remote operations, as data can be distributed across different nodes or servers, reducing network latency and improving performance. Therefore, the correct answer is efficiency.

Explanation

Partitioning provides the advantage of efficiency. By dividing a larger problem or dataset into smaller, more manageable parts, partitioning allows for parallel processing and distributed computing. This can significantly improve the overall efficiency of a system or algorithm, as multiple tasks can be executed simultaneously. Additionally, partitioning can help optimize remote operations, as data can be distributed across different nodes or servers, reducing network latency and improving performance. Therefore, the correct answer is efficiency.

95. User-defined transactions can improve system performance because:

Transactions are processed as sets, reducing system overhead

Transactions are mapped to SQL statements

Speed is improved due to query optimization

All of the above

User-defined transactions can improve system performance because they are processed as sets, which reduces system overhead. When transactions are processed as sets, the system can perform multiple operations together, minimizing the overhead of starting and ending each individual transaction. This approach increases efficiency and reduces the overall processing time. Therefore, user-defined transactions can enhance system performance by minimizing the resources required for transaction processing.

Explanation

User-defined transactions can improve system performance because they are processed as sets, which reduces system overhead. When transactions are processed as sets, the system can perform multiple operations together, minimizing the overhead of starting and ending each individual transaction. This approach increases efficiency and reduces the overall processing time. Therefore, user-defined transactions can enhance system performance by minimizing the resources required for transaction processing.

96. A constraint between two attributes is called a(n):

Functional relation

Attribute dependency

Functional dependency

Functional relation constraint

A constraint between two attributes is called a functional dependency. This means that one attribute's value is determined by another attribute's value. In other words, if you know the value of one attribute, you can determine the value of the other attribute. This constraint helps maintain data integrity and ensures that the database remains consistent.

Explanation

A constraint between two attributes is called a functional dependency. This means that one attribute's value is determined by another attribute's value. In other words, if you know the value of one attribute, you can determine the value of the other attribute. This constraint helps maintain data integrity and ensures that the database remains consistent.

97. The MERGE command:

Allows one to combine the INSERT and UPDATE operations

Allows one to combine the INSERT and DELETE operations

Joins 2 tables together

None of the above

The MERGE command allows one to combine the INSERT and UPDATE operations. It is used to update a target table based on the values from a source table, and if a matching row exists, it updates it, otherwise, it inserts a new row. This command is useful when dealing with large datasets and simplifies the process of updating or inserting data into a table.

Explanation

The MERGE command allows one to combine the INSERT and UPDATE operations. It is used to update a target table based on the values from a source table, and if a matching row exists, it updates it, otherwise, it inserts a new row. This command is useful when dealing with large datasets and simplifies the process of updating or inserting data into a table.

98. An index of columns from two or more tables that come from the same domain of values is called a:

Bitmap index

Multivalued index

Join index

Transaction index

A join index is an index that is created on columns from multiple tables that belong to the same domain of values. It is used to improve the performance of queries that involve joining these tables. By creating a join index, the database can precompute the join operation and store the results in the index, allowing for faster retrieval of data when executing queries that involve joining these tables.

Explanation

A join index is an index that is created on columns from multiple tables that belong to the same domain of values. It is used to improve the performance of queries that involve joining these tables. By creating a join index, the database can precompute the join operation and store the results in the index, allowing for faster retrieval of data when executing queries that involve joining these tables.

99. A(n) _______________ is a technique for physically arranging the records of a file on secondary storage devices

Physical pointer

Retrieval program

File organization

Update program

File organization refers to the technique of arranging the records of a file on secondary storage devices. It determines how the data is stored, accessed, and retrieved from the file. Different file organization methods include sequential, indexed, and hashed. Each method has its own advantages and disadvantages, depending on the specific requirements of the application. Therefore, file organization plays a crucial role in optimizing data storage and retrieval efficiency.

Explanation

File organization refers to the technique of arranging the records of a file on secondary storage devices. It determines how the data is stored, accessed, and retrieved from the file. Different file organization methods include sequential, indexed, and hashed. Each method has its own advantages and disadvantages, depending on the specific requirements of the application. Therefore, file organization plays a crucial role in optimizing data storage and retrieval efficiency.

100. What results would the following SQL statement produce? SQL> select owner, table_name from dba_tables where table_name = 'CUSTOMERS';

A listing of all customers in the customer table

A listing of the owener of the customer table

A listing of the owner of the customer table as well as customers

The given SQL statement will produce a listing of the owner of the customer table. The SELECT statement is retrieving the "owner" and "table_name" columns from the "dba_tables" table. The WHERE clause filters the results to only include rows where the "table_name" is equal to 'CUSTOMERS'. Therefore, the output will consist of the owner(s) of the customer table(s) that match the specified condition.

Explanation

The given SQL statement will produce a listing of the owner of the customer table. The SELECT statement is retrieving the "owner" and "table_name" columns from the "dba_tables" table. The WHERE clause filters the results to only include rows where the "table_name" is equal to 'CUSTOMERS'. Therefore, the output will consist of the owner(s) of the customer table(s) that match the specified condition.

101. A contiguous section of disk storage space is called a(n):

Track

Sector

Extent

Tablespace

An extent is a contiguous section of disk storage space. It is a range of consecutive blocks allocated to a file or database object. Extents are used to efficiently allocate and manage disk space, as they reduce fragmentation and improve I/O performance. Therefore, an extent is the correct term for a contiguous section of disk storage space.

Explanation

An extent is a contiguous section of disk storage space. It is a range of consecutive blocks allocated to a file or database object. Extents are used to efficiently allocate and manage disk space, as they reduce fragmentation and improve I/O performance. Therefore, an extent is the correct term for a contiguous section of disk storage space.

102. A two-dimensional table of data is called a:

Group

Set

Declaration

Relation

A two-dimensional table of data is commonly referred to as a "relation" in the field of database management. This term is used to describe the organization and structure of data in a tabular format, where each row represents a record and each column represents a specific attribute or field. The use of the term "relation" emphasizes the interconnectedness and interdependence of the data within the table, highlighting the ability to establish relationships and perform operations such as joins and queries.

Explanation

A two-dimensional table of data is commonly referred to as a "relation" in the field of database management. This term is used to describe the organization and structure of data in a tabular format, where each row represents a record and each column represents a specific attribute or field. The use of the term "relation" emphasizes the interconnectedness and interdependence of the data within the table, highlighting the ability to establish relationships and perform operations such as joins and queries.

103. _________ differs from array because it can contain duplicates

BIGINT

XML

MULTISET

TABLE

A multiset differs from an array because it can contain duplicates. In an array, each element is unique and there can be no duplicate values. However, in a multiset, duplicate values are allowed and can be present multiple times. This means that a multiset can have multiple occurrences of the same value, whereas an array cannot.

Explanation

A multiset differs from an array because it can contain duplicates. In an array, each element is unique and there can be no duplicate values. However, in a multiset, duplicate values are allowed and can be present multiple times. This means that a multiset can have multiple occurrences of the same value, whereas an array cannot.

104. Establishing IF-THEN-ELSE logical processing within an SQL statement can be accomplished by:

Using the if-then-else construct

Using the immediate if statement

Using the CASE keyword in a statement

Using a subquery

The correct answer is using the CASE keyword in a statement. The CASE keyword allows for conditional logic within an SQL statement. It can be used to evaluate multiple conditions and return different results based on those conditions. It is a versatile tool for implementing IF-THEN-ELSE logic in SQL queries.

Explanation

The correct answer is using the CASE keyword in a statement. The CASE keyword allows for conditional logic within an SQL statement. It can be used to evaluate multiple conditions and return different results based on those conditions. It is a versatile tool for implementing IF-THEN-ELSE logic in SQL queries.

105. A named set of SQL statements that are considered when a data modification occurs are called

Stored procedures

Treatments

Triggers

Trapdoors

Triggers are a named set of SQL statements that are executed automatically when a specified event occurs, such as a data modification. They are used to enforce data integrity and consistency by allowing actions to be performed before or after the event. Triggers can be used to validate data, update other tables, or perform any other necessary actions based on the event. Stored procedures, on the other hand, are named sets of SQL statements that are stored in the database and can be executed on demand. Treatments and trapdoors are not commonly used terms in the context of SQL.

Explanation

Triggers are a named set of SQL statements that are executed automatically when a specified event occurs, such as a data modification. They are used to enforce data integrity and consistency by allowing actions to be performed before or after the event. Triggers can be used to validate data, update other tables, or perform any other necessary actions based on the event. Stored procedures, on the other hand, are named sets of SQL statements that are stored in the database and can be executed on demand. Treatments and trapdoors are not commonly used terms in the context of SQL.

106. The following query will execute without errors: SQL> select customer.customer_name, salesman.sales_quota from customer where customer.salesman_id = (select saleman_id where lname = 'SMITH');

True

False

The query will not execute without errors because the subquery in the WHERE clause is missing the FROM clause. The subquery should be modified to include the FROM clause and specify the table name for the salesman_id column.

Explanation

The query will not execute without errors because the subquery in the WHERE clause is missing the FROM clause. The subquery should be modified to include the FROM clause and specify the table name for the salesman_id column.

107. A relation that contains minimal redundancy and allows easy use is considered to be:

Clean

Simple

Complex

Well structured

A relation that is well structured means that it is organized and designed in a way that minimizes redundancy, meaning that there is no unnecessary repetition of data. It also implies that the relation is easy to use and navigate, making it user-friendly. Therefore, a well-structured relation is the one that contains minimal redundancy and allows easy use.

Explanation

A relation that is well structured means that it is organized and designed in a way that minimizes redundancy, meaning that there is no unnecessary repetition of data. It also implies that the relation is easy to use and navigate, making it user-friendly. Therefore, a well-structured relation is the one that contains minimal redundancy and allows easy use.

108. All of the following are part of the coding structure for triggers EXCEPT:

Event

Condition

Selection

Action

The coding structure for triggers typically includes an event, which is the specific action that triggers the code, a condition, which specifies when the trigger should be activated, and an action, which defines what should happen when the trigger is activated. However, "selection" is not typically part of the coding structure for triggers. It seems to be unrelated to the concept of triggers and does not fit into the typical structure.

Explanation

The coding structure for triggers typically includes an event, which is the specific action that triggers the code, a condition, which specifies when the trigger should be activated, and an action, which defines what should happen when the trigger is activated. However, "selection" is not typically part of the coding structure for triggers. It seems to be unrelated to the concept of triggers and does not fit into the typical structure.

109. A join that is based upon equality between values in two common columns with the same name and where one duplicate column has been removed is called a(n):

Equi-join

Natural join

Multivariate join

Inner join

A natural join is a type of join that is based upon equality between values in two common columns with the same name. In this type of join, one duplicate column is removed, resulting in a join that combines rows from two tables based on matching values in the common column. Therefore, the correct answer for this question is natural join.

Explanation

A natural join is a type of join that is based upon equality between values in two common columns with the same name. In this type of join, one duplicate column is removed, resulting in a join that combines rows from two tables based on matching values in the common column. Therefore, the correct answer for this question is natural join.

110. A domain definition consists of the following components EXCEPT:

Domain name

Data type

Integrity constraint

Size

A domain definition consists of the domain name, data type, and size. The integrity constraint is not a component of a domain definition. Integrity constraints are rules or conditions that are applied to the data within a domain to ensure its accuracy and consistency. They are separate from the domain definition itself, which primarily defines the characteristics and properties of the data within a domain.

Explanation

A domain definition consists of the domain name, data type, and size. The integrity constraint is not a component of a domain definition. Integrity constraints are rules or conditions that are applied to the data within a domain to ensure its accuracy and consistency. They are separate from the domain definition itself, which primarily defines the characteristics and properties of the data within a domain.

111. A join in which the joining condition is based on equality between values in the common columns is called a(n):

Equi-join

Uni-lateral join

Natural join

A and C

An equi-join is a type of join where the joining condition is based on equality between values in the common columns of the two tables being joined. A natural join is also a type of join where the joining condition is based on equality between values in the common columns. Therefore, the correct answer is A and C, as both equi-join and natural join satisfy the given condition.

Explanation

An equi-join is a type of join where the joining condition is based on equality between values in the common columns of the two tables being joined. A natural join is also a type of join where the joining condition is based on equality between values in the common columns. Therefore, the correct answer is A and C, as both equi-join and natural join satisfy the given condition.

112. Within Oracle, the named set of storage elements in which physical files for database tables may be stored is called a(n):

Extent

Table

Tablespace

Partition

A tablespace in Oracle is a named set of storage elements where physical files for database tables can be stored. It provides a logical structure for organizing and managing database objects, such as tables, indexes, and partitions. By allocating space within a tablespace, Oracle can efficiently manage the storage and retrieval of data. Multiple tablespaces can be created within a database, allowing for better control over storage allocation and performance optimization.

Explanation

A tablespace in Oracle is a named set of storage elements where physical files for database tables can be stored. It provides a logical structure for organizing and managing database objects, such as tables, indexes, and partitions. By allocating space within a tablespace, Oracle can efficiently manage the storage and retrieval of data. Multiple tablespaces can be created within a database, allowing for better control over storage allocation and performance optimization.

113. All of the following are advantages of SQL-invoked routiens EXCEPT:

Flexibility

Efficiency

Sharability

Security

SQL-invoked routines, such as stored procedures and functions, provide several advantages including flexibility, efficiency, and sharability. However, they do not inherently provide security. While it is possible to implement security measures within SQL-invoked routines, their advantages do not directly include security features. Therefore, the correct answer is security.

Explanation

SQL-invoked routines, such as stored procedures and functions, provide several advantages including flexibility, efficiency, and sharability. However, they do not inherently provide security. While it is possible to implement security measures within SQL-invoked routines, their advantages do not directly include security features. Therefore, the correct answer is security.

114. A new set of analytical functions added in SQL:200n are referred to as:

OLAF functions

MOLAP functions

Average functions

OLAP Functions

The correct answer is OLAP Functions. OLAP stands for Online Analytical Processing, and these functions are specifically designed to support complex data analysis and reporting tasks in a data warehouse environment. They provide capabilities such as aggregating data, performing calculations, and generating reports based on multidimensional data models. These functions are a valuable addition to SQL:200n as they enhance the analytical capabilities of the language and enable more sophisticated data analysis.

Explanation

The correct answer is OLAP Functions. OLAP stands for Online Analytical Processing, and these functions are specifically designed to support complex data analysis and reporting tasks in a data warehouse environment. They provide capabilities such as aggregating data, performing calculations, and generating reports based on multidimensional data models. These functions are a valuable addition to SQL:200n as they enhance the analytical capabilities of the language and enable more sophisticated data analysis.

115. A(n) __________ is a field of data used to locate a related field or record

Key

Index

Lock

Pointer

A pointer is a field of data used to locate a related field or record. Pointers are commonly used in programming to store memory addresses of other variables or objects. By storing the memory address of a related field or record in a pointer, it becomes easier and more efficient to access and manipulate the data. Pointers essentially "point" to the location of the data, allowing for quick and direct access.

Explanation

A pointer is a field of data used to locate a related field or record. Pointers are commonly used in programming to store memory addresses of other variables or objects. By storing the memory address of a related field or record in a pointer, it becomes easier and more efficient to access and manipulate the data. Pointers essentially "point" to the location of the data, allowing for quick and direct access.

116. Database access frequencies are estimated from:

Transaction volumes

User logins

Security violations

None of the above

Database access frequencies can be estimated based on transaction volumes. Transaction volumes refer to the number of operations or transactions performed on the database, which can indicate the frequency of accessing and manipulating data. By analyzing the transaction volumes, one can determine how often the database is being accessed and used, allowing for better optimization and resource allocation. Therefore, transaction volumes are a reliable measure for estimating database access frequencies.

Explanation

Database access frequencies can be estimated based on transaction volumes. Transaction volumes refer to the number of operations or transactions performed on the database, which can indicate the frequency of accessing and manipulating data. By analyzing the transaction volumes, one can determine how often the database is being accessed and used, allowing for better optimization and resource allocation. Therefore, transaction volumes are a reliable measure for estimating database access frequencies.

117. A join in which rows that do not have matching values in common columns are still included in the result table is called a(n):

Natural join

Equi-join

Outer join

Union join

An outer join is a type of join where rows that do not have matching values in common columns are still included in the result table. This means that even if there is no match between the rows in the joined tables, the rows will still be included in the result. This is different from a natural join or equi-join, where only the rows with matching values in common columns are included. A union join is not a valid term in the context of joins.

Explanation

An outer join is a type of join where rows that do not have matching values in common columns are still included in the result table. This means that even if there is no match between the rows in the joined tables, the rows will still be included in the result. This is different from a natural join or equi-join, where only the rows with matching values in common columns are included. A union join is not a valid term in the context of joins.

118. All of the following are horizontal partitioning methods in Oracle EXCEPT:

Key range partitioning

Hash partitioning

Multivalued partitioning

Composite partitioning

Multivalued partitioning is not a horizontal partitioning method in Oracle. Horizontal partitioning is a technique used to divide a table into multiple smaller tables based on a specific criterion, such as a range of values or a hash function. Key range partitioning divides the table based on a specified range of key values, hash partitioning distributes the data based on a hash function, and composite partitioning combines multiple partitioning methods. However, multivalued partitioning is not a recognized technique in Oracle for horizontal partitioning.

Explanation

Multivalued partitioning is not a horizontal partitioning method in Oracle. Horizontal partitioning is a technique used to divide a table into multiple smaller tables based on a specific criterion, such as a range of values or a hash function. Key range partitioning divides the table based on a specified range of key values, hash partitioning distributes the data based on a hash function, and composite partitioning combines multiple partitioning methods. However, multivalued partitioning is not a recognized technique in Oracle for horizontal partitioning.

119. While Oracle has responsibility for managing data inside a tablespace, the tablespace as a while is managed by the:

User

Database administrator

Application developer

Operating system

The operating system is responsible for managing the tablespace as a whole. Although Oracle is responsible for managing the data inside the tablespace, the overall management and control of the tablespace is handled by the operating system. This includes tasks such as allocating and deallocating space, managing file systems, and performing backup and recovery operations. The user, database administrator, and application developer have specific roles and responsibilities within the Oracle database, but they do not directly manage the tablespace at the operating system level.

Explanation

The operating system is responsible for managing the tablespace as a whole. Although Oracle is responsible for managing the data inside the tablespace, the overall management and control of the tablespace is handled by the operating system. This includes tasks such as allocating and deallocating space, managing file systems, and performing backup and recovery operations. The user, database administrator, and application developer have specific roles and responsibilities within the Oracle database, but they do not directly manage the tablespace at the operating system level.

120. If foreign key is referenced to the primary key in the same relation, we call it:

Primary

Recursive primary

Composite

Recursive foreign

If a foreign key is referenced to the primary key in the same relation, it is called a recursive foreign key. This means that the foreign key is pointing back to the same table and is used to establish a relationship between different rows within the same table. This can be useful in scenarios where there is a hierarchical or recursive relationship between entities in the table.

Explanation

If a foreign key is referenced to the primary key in the same relation, it is called a recursive foreign key. This means that the foreign key is pointing back to the same table and is used to establish a relationship between different rows within the same table. This can be useful in scenarios where there is a hierarchical or recursive relationship between entities in the table.