Podcast
Questions and Answers
What is the main purpose of mappings among schema levels in the three-schema architecture?
What is the main purpose of mappings among schema levels in the three-schema architecture?
- To eliminate the need for any conversions between data types
- To define the structure of user data without worrying about how it is stored internally (correct)
- To enforce data integrity constraints across all levels of the architecture
- To speed up query performance in the database
Which aspect best describes the difference between a procedural and nonprocedural DML?
Which aspect best describes the difference between a procedural and nonprocedural DML?
- The type of users who can access the database using different languages
- The ability to directly specify what data is required without specifying how to get it (procedural) vs. specifying both what data is required and how to get it (nonprocedural) (correct)
- The level of security provided by the database during transactions
- The speed at which queries are executed by the database engine
What is the key difference between logical data independence and physical data independence?
What is the key difference between logical data independence and physical data independence?
- Logical data independence involves user-friendly interfaces, while physical data independence focuses on performance optimization.
- Logical data independence allows for more complex queries, while physical data independence simplifies the storage structures.
- Logical data independence is focused on security measures, while physical data independence works on backup and recovery strategies.
- Logical data independence deals with changes to the conceptual schema without affecting external schemas, while physical data independence deals with changes in the internal schema. (correct)
Why do we need a distinction between database schema and database state?
Why do we need a distinction between database schema and database state?
What is one of the primary reasons for using n-tier architecture over three-tier architecture?
What is one of the primary reasons for using n-tier architecture over three-tier architecture?
Which statement describes the role of a Data Definition Language (DDL) in a database system?
Which statement describes the role of a Data Definition Language (DDL) in a database system?
In a Web-based system for airline reservations and ticket sales, which DBMS architecture would be the best choice?
In a Web-based system for airline reservations and ticket sales, which DBMS architecture would be the best choice?
In a database schema for an airline reservation system, which column or group of columns must be unique across all rows?
In a database schema for an airline reservation system, which column or group of columns must be unique across all rows?
When designing views for different users of the database, what should be considered?
When designing views for different users of the database, what should be considered?
Which type of constraint dictates that a column or a group of columns must be unique across all rows in a table?
Which type of constraint dictates that a column or a group of columns must be unique across all rows in a table?
When designing a database schema, what should additional information and constraints represent?
When designing a database schema, what should additional information and constraints represent?
For an airline reservation system, which DBMS architecture would not be a good choice?
For an airline reservation system, which DBMS architecture would not be a good choice?
