Sofia Relational Databases Unit 3.1
Latest Update Graded A+
What is a primary key in a relational database?
✔✔A unique identifier for each record in a table.
Why are foreign keys important in relational databases?
✔✔They establish relationships between tables and ensure data integrity.
What is the purpose of a JOIN operation in SQL?
✔✔To combine rows from two or more tables based on a related column.
How does normalization benefit relational databases?
✔✔It reduces data redundancy and improves data integrity.
What is the role of an index in a relational database?
✔✔To speed up data retrieval by creating a reference for quicker access.
1
,Why is it important to define data types for columns in a database table?
✔✔To ensure that data is stored consistently and meets specific constraints.
What happens if you attempt to delete a record that has related foreign key constraints?
✔✔The operation will fail unless cascading rules are applied or the relationships are resolved.
How does a relational database handle many-to-many relationships?
✔✔By using a junction table to link the two related tables.
What is the purpose of a schema in a relational database?
✔✔To define the structure and organization of tables, columns, and relationships.
Why is it necessary to use constraints like UNIQUE or NOT NULL in relational databases?
✔✔To enforce rules that ensure data quality and consistency.
How does a transaction ensure data consistency in a relational database?
✔✔By grouping operations into a single unit that either fully commits or fully rolls back.
2
, What is a composite key in a relational database?
✔✔A key that consists of two or more columns to uniquely identify a record.
Why is the ACID property important in relational databases?
✔✔It ensures reliability in transactions by maintaining atomicity, consistency, isolation, and
durability.
What is the difference between a clustered and a non-clustered index?
✔✔A clustered index sorts the physical data, while a non-clustered index provides a separate
structure pointing to the data.
How do relational databases enforce referential integrity?
✔✔By using foreign key constraints to ensure relationships between tables are maintained.
What is a view in a relational database?
✔✔A virtual table created from a query that can simplify data access and enhance security.
Why might a database administrator create a trigger?
3
Latest Update Graded A+
What is a primary key in a relational database?
✔✔A unique identifier for each record in a table.
Why are foreign keys important in relational databases?
✔✔They establish relationships between tables and ensure data integrity.
What is the purpose of a JOIN operation in SQL?
✔✔To combine rows from two or more tables based on a related column.
How does normalization benefit relational databases?
✔✔It reduces data redundancy and improves data integrity.
What is the role of an index in a relational database?
✔✔To speed up data retrieval by creating a reference for quicker access.
1
,Why is it important to define data types for columns in a database table?
✔✔To ensure that data is stored consistently and meets specific constraints.
What happens if you attempt to delete a record that has related foreign key constraints?
✔✔The operation will fail unless cascading rules are applied or the relationships are resolved.
How does a relational database handle many-to-many relationships?
✔✔By using a junction table to link the two related tables.
What is the purpose of a schema in a relational database?
✔✔To define the structure and organization of tables, columns, and relationships.
Why is it necessary to use constraints like UNIQUE or NOT NULL in relational databases?
✔✔To enforce rules that ensure data quality and consistency.
How does a transaction ensure data consistency in a relational database?
✔✔By grouping operations into a single unit that either fully commits or fully rolls back.
2
, What is a composite key in a relational database?
✔✔A key that consists of two or more columns to uniquely identify a record.
Why is the ACID property important in relational databases?
✔✔It ensures reliability in transactions by maintaining atomicity, consistency, isolation, and
durability.
What is the difference between a clustered and a non-clustered index?
✔✔A clustered index sorts the physical data, while a non-clustered index provides a separate
structure pointing to the data.
How do relational databases enforce referential integrity?
✔✔By using foreign key constraints to ensure relationships between tables are maintained.
What is a view in a relational database?
✔✔A virtual table created from a query that can simplify data access and enhance security.
Why might a database administrator create a trigger?
3
