BCA 3rd sem Question

I have Data Science Questions and answers:

Unit I:
  1. What are the advantages and disadvantages of using a database approach over a traditional file processing system?
  2. Explain the three schema architectures of a database system and give an example.
  3. What are the components of an E-R model and how are they represented graphically?
Unit II:
  1. What are the differences between supertype, subtype, specialization, and generalization in an enhanced E-R model? Give an example of each.
  2. What are the structural and operational constraints on a relationship type?
  3. Explain how to transform an EER diagram into a relational schema.
Unit III:
  1. What are the basic operations of relational algebra and how are they used to manipulate relations?
  2. What are the differences between relational algebra and relational calculus?
  3. Write a basic SQL query to retrieve data from a table and apply some conditions and aggregations to it.
Unit IV:
  1. What are the factors that influence the choice of a file organization and an indexing technique for a database?
  2. Compare and contrast the ISAM and B+ tree indexing methods.
  3. What are the advantages and disadvantages of static, extendible, and linear hashing?
Unit V:
  1. What are the ACID properties of a transaction and why are they important for ensuring the consistency and reliability of a database?
  2. What are the problems that can arise from concurrent execution of transactions and how can they be prevented or detected?
  3. What are the basic principles of lock-based concurrency control and how can deadlock be avoided or resolved?