Write short note on Indexing .

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 Indexing 

 Indexing is used to optimize the performance of a database by minimizing the number of disk accesses required when a query is processed. The index is a type of structure having only two columns. The first column comprises a copy of the primary or candidate Key of a table. The Second Column contains a set of pointers for holding the address of the disk block where Specific key values are stored.

Advantages of indexing

  •  Better performance of queries.
  • Fast Searching from the database.
  • Fast retrieval of data 
  • Increase performance in SELECT query.

Disadvantages of indexing

  • Indexing takes more space.
  • Decrease performance in INSERT, DELETE, and UPDATE query.
Figure: Structure of index











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