Which one of the following has the most negligible impact on the integrity of a relational database? (Wentz QOTD)
A. Transactions
B. Foreign key constraints
C. Primary key constraints
D. Data Query Language (DQL)
Kindly be reminded that the suggested answer is for your reference only. It doesn’t matter whether you have the right or wrong answer. What really matters is your reasoning process and justifications.
My suggested answer is D. Data Query Language (DQL).
Wentz’s book, The Effective CISSP: Security and Risk Management, helps CISSP and CISM aspirants build a solid conceptual security model. It is a tutorial for information security and a supplement to the official study guides for the CISSP and CISM exams and an informative reference for security professionals.
Data Query Language (DQL) in a relational database is used to select or inquiry data. It won’t affect integrity because it doesn’t modify data.
Relational Database Integrity
There are three types of integrity for relational databases: entity integrity, semantic integrity, and referential integrity.
- A relational database stores data in a table, in which a primary key (PK) is assigned to enforce “entity integrity.”
- Each column or field of a table has specific specifications, e.g., data type, length, value domain, etc. to enforce the “semantic integrity.”
- In a master/detail or parent/child relationship between two tables, associating the child’s foreign key to its parent’s primary key creates the so-called foreign key constraint to enforce “referential integrity.” However, not all database designers will define foreign key constraints. Transactions come into play. It’s common to use both foreign key constraints and transactions simultaneously to enforce referential integrity.
Transaction
To persist or save a real-life or business transaction, it typically transforms into one or more database work or tasks. From the perspective of data persistence or database, a transaction is a unit of work. All work is either successfully done or undone if any problem occurs.
Reference
- Primary and Foreign Key Constraints
- Transactions (Transact-SQL)
- CISSP PRACTICE QUESTIONS – 20200318
- CISSP PRACTICE QUESTIONS – 20200817
以下哪一項對關聯式資料庫的完整性影響最小？ (Wentz QOTD)
A. 交易
B. 外鍵約束
C. 主鍵約束
D. 數據查詢語言 (DQL)