Match the following: List-1 List-2 I) Relational Algebra Q) Procedural Query…
2018
Match the following:
List-1 | List-2 |
I) Relational Algebra | Q) Procedural Query Language |
II) Relational Calculus | P) Non-Procedural Query Language |
III) Generalization | S) Bottom-Up Approach |
IV) Specialization | R) Top-Down Approach |
- A.
I-Q, II-P, III-R, IV-S
- B.
I-Q, II-P, III-S, IV-R
- C.
I-P, II-Q, III-S, IV-R
- D.
I-P, II-Q, III-R, IV-S
Attempted by 328 students.
Show answer & explanation
Correct answer: B
Concept: Relational query languages are classified as procedural or non-procedural — a procedural language (Relational Algebra) specifies both the result and the exact sequence of operations to obtain it, while a non-procedural/declarative language (Relational Calculus) specifies only the desired result. Separately, in ER modelling, Generalization is the bottom-up process of combining several lower-level entity sets that share common attributes into one higher-level entity set, while Specialization is the reverse, top-down process of dividing a higher-level entity set into distinct lower-level subsets based on distinguishing features.
List-1 item | List-2 match | Why |
|---|---|---|
I) Relational Algebra | Q) Procedural Query Language | It performs operations (select, project, join, etc.) in a defined sequence to retrieve data. |
II) Relational Calculus | P) Non-Procedural Query Language | It states the desired result through a formula, without specifying the sequence of operations. |
III) Generalization | S) Bottom-Up Approach | It starts from several specific entity sets and generalizes upward into one higher-level set. |
IV) Specialization | R) Top-Down Approach | It starts from one general entity set and specializes downward into distinguishing subsets. |
Cross-check against the other options:
I-Q, II-P, III-R, IV-S reverses only the ER-model pairing — it assigns Generalization to the top-down direction and Specialization to the bottom-up direction, which is backwards.
I-P, II-Q, III-S, IV-R reverses only the query-language pairing — it assigns Relational Algebra to non-procedural and Relational Calculus to procedural, which is backwards.
I-P, II-Q, III-R, IV-S reverses both pairings at once.
Thus the correct matching is I-Q, II-P, III-S, IV-R.