Exploring Database Management Systems

What are the main components of a database system architecture?

• The main components of a database system architecture are the DBMS, the database, application programs, and users.

• The main components are the server, network, and storage devices.

• The main components consist of hardware, software, and network protocols.

• The main components include only the database and users.

Explain the differences between hierarchical, network, and relational data models.

• Hierarchical: tree structure, single parent; Network: graph structure, multiple parents; Relational: table-based, flexible relationships.

• Hierarchical: grid structure, multiple parents; Network: table structure, single parent; Relational: graph-based, complex relationships.

• Hierarchical: circular structure, no parents; Network: linear structure, one parent; Relational: document-based, rigid relationships.

• Hierarchical: flat structure, multiple parents; Network: tree structure, single parent; Relational: object-based, fixed relationships.

What is an ER diagram and what are its basic components?

• Entities, attributes, and diagrams

• Attributes, relationships, and tables

• Entities, relationships, and keys

• The basic components of an ER diagram include entities, attributes, and relationships.

How can ER diagrams be extended to include more complex relationships?

• ER diagrams cannot include attributes for entities.

• ER diagrams can include weak entities, ternary relationships, and generalization/specialization.

• ER diagrams are limited to one-to-one relationships only.

• ER diagrams can only represent binary relationships.

What are the common types of failures in database systems?

• Database upgrades

• Common types of failures in database systems include hardware failures, software bugs, human errors, network issues, and data corruption.

• Increased storage capacity

• Power outages

Describe a recovery algorithm used in database management.

• Shadow Paging

• Database Replication Method

• Two-Phase Commit Protocol

• Write-Ahead Logging (WAL) protocol

What is the purpose of SQL in database management?

• The purpose of SQL in database management is to manage and manipulate relational databases.

• To visualize data in spreadsheets.

• To create non-relational databases.

• To perform statistical analysis on data.

List and explain three types of constraints in SQL.

• DEFAULT

• INDEX

• PRIMARY KEY, FOREIGN KEY, CHECK

• UNIQUE

What is a JOIN operation in SQL and why is it used?

• A JOIN operation in SQL is used to delete rows from a table.

• A JOIN operation in SQL is used to create new tables from existing ones.

• A JOIN operation in SQL is used to combine rows from two or more tables based on a related column.

• A JOIN operation in SQL is used to sort data within a single table.

Differentiate between INNER JOIN and OUTER JOIN.

• INNER JOIN can return unmatched rows; OUTER JOIN cannot.

• INNER JOIN is used for aggregating data; OUTER JOIN is used for filtering data.

• INNER JOIN returns all rows from both tables; OUTER JOIN returns only matched rows.

• INNER JOIN returns matched rows; OUTER JOIN returns all rows from one table and matched rows from the other.