Interview Questions - DBMS Basics

53.
What is indexing and what are the different kinds of indexing?
Indexing is a technique for determining how quickly specific data can be found.
Types:
  1. Binary search style indexing
  2. B-Tree indexing
  3. Inverted list indexing
  4. Memory resident table
  5. Table indexing

54.
What is system catalog or catalog relation? How is better known as?
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.

55.
What is meant by query optimization?
The phase that identifies an efficient execution plan for evaluating a query that has the least estimated cost is referred to as query optimization.

56.
What is durability in DBMS?
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.