Database-MySQL [3i Infotech Placement]: Sample Questions 40 - 41 of 162

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Question 40

Describe in Detail Essay▾

What is a checkpoint and when does it occur?

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Explanation

Understanding of Example of Checkpoints
  • A Checkpoint is like a snapshot of the DBMS state.
  • The DBMS can reduce the amount of work to be done during restart in the event of subsequent crashes, by taking checkpoints,

Checkpoint automatically occurs at:

  • Checkpoint automatically occurs at a log switch.
  • When we will specify the parameter fast_start_mttr_target =< No of Second > .
  • When normally forced by the administrator.
  • If the data file is offline checkpoint will occur.

Question 41

Describe in Detail Essay▾

What is DDL (Data Definition Language) ?

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Explanation

Define Data Defination Language (DDL)
  • DDL is short name of Data Definition Language, which deals with database schemas and descriptions, of how the data should reside in the database.
    • CREATE - to create database and its objects like (table, index, views, store procedure, function and triggers)
    • ALTER - alters the structure of the existing database
    • DROP - delete objects from the database
    • TRUNCATE - remove all records from a table, including all spaces allocated for the records are removed
    • COMMENT - add comments to the data dictionary
    • RENAME - rename an object