Most Popular Database Queries For an Interview
Mysql 23-Feb-2019

Most Popular Database Queries For an Interview

Hi Programmers, In this article, we discuss most Popular Database Queries For an Interview.

Do you want to apply at Google, Amazon, Microsoft, Facebook, Apple or any big MNC company? If yes, they must go through below database query questions. It’s most frequently asked questions in all companies. Most Popular Database Queries For an Interview:

Important SQL Queries Asked in an Interview

  • Customer Who Never Order
  • Delete Duplicate Emails
  • Rising Temperature
  • Department Highest Salary
  • Swap Sex Field
  • Combine Two Tables
  • Nth Highest Salary

Define Words

  • Join – Join is the process of explaining the relationship between different tables by combining columns from one or more table having common values in each.
  • Index hunting – Index hunting is the process of boosting the collection of indexes which help in improving the query performance as well as the speed of the database.
  • Database partitioning – Database partitioning is the process of partitioning tables, indexes into smaller pieces in order to manage and access the data at a finer level.
  • Data Dictionary – Data dictionary is a set of information describing the content and structure of the tables and database objects.
  • Database Triggers – A set of commands that automatically get executed when an event like Before Insert, After Insert, On Update, On Delete of row occurs in a table is called as Database trigger.
  • Stored procedure – A Stored procedure is a collection of pre-compiled SQL Queries, which when executed denotes a program taking input, process and gives the output.
  • Data Warehousing – The storage as well as access to data, that is being derived from the transactions and other sources, from a central location in order to perform the analysis is called Data Warehousing.
  • Database lock – Database lock basically signifies the transaction about the current status of the data item i.e. whether that data is being used by other transactions or not at the present point of time.
  • Database transaction – Sequence of operation performed which changes the consistent state of the database to another is known as the database transaction.
  • E-R model – E-R model is an Entity-Relationship model which defines the conceptual view of the database.
  • Functional dependency – A relation is said to be in Functional dependency when one attribute uniquely defines another attribute.
  •  Data Independence – Data Independence refers to the ability to modify the schema definition in one level in such a way that it does not affect the schema definition in the next higher level.
  • Data Redundancy – Duplication of data in the database is known as Data redundancy.

These are the set of Database interview questions and answers which are mostly asked in the interview.

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