Sql Interview Question and Answers:
79. What is a Database instance?
A database instance (Server) is a set of memory structure and background processes that access a set of database files.
80. What are Roles?
Roles are named groups of related privileges that are granted to users or other roles.
81. What is SQLPlus?
SQLPlus is an application that recognizes & executes SQL commands & specialized SQL*Plus commands that can customize reports, provide help & edit facility & maintain system variables.
82. What is the difference between normalization and denormalization?
Normalizing data means eliminating redundant information from a table and organizing the data so that future changes to the table are easier.
Denormalization means allowing redundancy in a table. The main benefit of denormalization is improved performance with simplified data retrieval and manipulation.
83. What is a trigger?
Triggers are stored procedures created in order to enforce integrity rules in a database. A trigger is executed every time a data-modification operation occurs (i.e., insert, update or delete).
Triggers are executed automatically on occurance of one of the data-modification operations.
84. What is the difference between static and dynamic SQL?
Static SQL is hard-coded in a program when the programmer knows the statements to be executed.
Dynamic SQL the program must dynamically allocate memory to receive the query results.
79. What is a Database instance?
A database instance (Server) is a set of memory structure and background processes that access a set of database files.
80. What are Roles?
Roles are named groups of related privileges that are granted to users or other roles.
81. What is SQLPlus?
SQLPlus is an application that recognizes & executes SQL commands & specialized SQL*Plus commands that can customize reports, provide help & edit facility & maintain system variables.
82. What is the difference between normalization and denormalization?
Normalizing data means eliminating redundant information from a table and organizing the data so that future changes to the table are easier.
Denormalization means allowing redundancy in a table. The main benefit of denormalization is improved performance with simplified data retrieval and manipulation.
83. What is a trigger?
Triggers are stored procedures created in order to enforce integrity rules in a database. A trigger is executed every time a data-modification operation occurs (i.e., insert, update or delete).
Triggers are executed automatically on occurance of one of the data-modification operations.
84. What is the difference between static and dynamic SQL?
Static SQL is hard-coded in a program when the programmer knows the statements to be executed.
Dynamic SQL the program must dynamically allocate memory to receive the query results.
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