DATABASE MANAGEMENT SYSTEM
106402Unit 5 – Advanced Topics
Q1i. The Object Query Language is which of the following? - (i) Similar to SQL and uses a select-from-where structure (ii) Similar to SQL and uses a select-where structure (ii) Similar to SQL and uses a from-where structure (iv) Not similar to SQL20212m
Unit 5 – Advanced Topics
View this question on its own page →The Object Query Language is which of the following?
- (i) Similar to SQL and uses a select-from-where structure
(ii) Similar to SQL and uses a select-where structure
(ii) Similar to SQL and uses a from-where structure
(iv) Not similar to SQL
Worked SolutionAnswer: (i) Similar to SQL and uses a select-from-where structure
Explanation: OQL (Object Query Language, ODMG standard) is declarative and SQL-like with SELECT-FROM-WHERE. Example: SELECT s.name FROM Students s WHERE s.cgpa > 8. It operates on objects, supports path expressions, but syntax closely resembles SQL. Not just select-where or from-where.
- (i) Similar to SQL and uses a select-from-where structure
Q7b. Explain web and distributed database with the help of example.20217m
Unit 5 – Advanced Topics
View this question on its own page →Explain web and distributed database with the help of example.
Worked SolutionWeb and Distributed Database with Examples:
Web Database: Database accessible via web interface, often three-tier (browser -> web server -> DB). Example: E-commerce site where product catalog stored in MySQL, accessed via PHP/Node.js, users interact via browser, queries via HTTP. Characteristics: stateless HTTP, connection pooling, security via HTTPS.
Distributed Database: Logically integrated but physically distributed across sites/nodes, appears as single DB. Types: Homogeneous (same DBMS) vs Heterogeneous (different). Fragmentation: Horizontal (rows), Vertical (columns), Replication. Example: Bank with branches in Mumbai and Delhi each store local accounts but global query can join - SELECT * FROM Accounts where branch='Mumbai' transparently via distributed query processor, with two-phase commit for atomicity. Advantages: locality, availability, scalability. Challenges: distributed concurrency, recovery, heterogeneity.
Both enable large-scale data access; web is front-end paradigm, distributed is storage architecture. Modern cloud combines both.