DBMS Basics - Technical Questions and Answers

DBMS - Database Management System
DBMS - Basics

51.	What is Domain-Key Normal Form?
	Answer: A relation is said to be in DKNF if all constraints and dependencies that should hold on the the constraint can be enforced by simply enforcing the domain constraint and key constraint on the relation. Workspace Report errors ... Name : Email: View Answer

52.

What are partial, alternate,, artificial, compound and natural key?

53.	What is indexing and what are the different kinds of indexing?
	Answer: Indexing is a technique for determining how quickly specific data can be found. Types: Binary search style indexing B-Tree indexing Inverted list indexing Memory resident table Table indexing Workspace Report errors ... Name : Email: View Answer

54.	What is system catalog or catalog relation? How is better known as?
	Answer: A RDBMS maintains a description of all the data that it contains, information about every relation and index that it contains. This information is stored in a collection of relations maintained by the system called metadata. It is also called data dictionary. Workspace Report errors ... Name : Email: View Answer

55.	What is meant by query optimization?
	Answer: The phase that identifies an efficient execution plan for evaluating a query that has the least estimated cost is referred to as query optimization. Workspace Report errors ... Name : Email: View Answer

56.	What is durability in DBMS?
	Answer: Once the DBMS informs the user that a transaction has successfully completed, its effects should persist even if the system crashes before all its changes are reflected on disk. This property is called durability. Workspace Report errors ... Name : Email: View Answer

57.

What do you mean by atomicity and aggregation?

58.	What is a Phantom Deadlock?
	Answer: In distributed deadlock detection, the delay in propagating local information might cause the deadlock detection algorithms to identify deadlocks that do not really exist. Such situations are called phantom deadlocks and they lead to unnecessary aborts. Workspace Report errors ... Name : Email: View Answer

59.	What is a checkpoint and When does it occur?
	Answer: A Checkpoint is like a snapshot of the DBMS state. By taking checkpoints, the DBMS can reduce the amount of work to be done during restart in the event of subsequent crashes. Workspace Report errors ... Name : Email: View Answer

60.	What are the different phases of transaction?
	Answer: Different phases are 1.) Analysis phase, 2.) Redo Phase, 3.) Undo phase. Workspace Report errors ... Name : Email: View Answer