WHAT IS INDEXING?

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WHAT IS INDEXING?..

Answer / savithri

A database index is a data structure that improves the
speed of operations in a table. Indices can be created
using one or more columns, providing the basis for both
rapid random lookups and efficient ordering of access to
records.

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WHAT IS INDEXING?..

Answer / sunny sarin

Indexing is creating an index for a table in the database to
fasten the speed of retrieving the results and for better
performance and efficiency.
Normally,indexes are of 2 types
unique
non-unique

unique index is created implicitly by the server whenever
any primary or foreign key constraint is given to any
column/s in the table.

we can also create a non unique index for any column in the
table.

indexes are stored on a different segment than the
table,this reduces contention on the table

indexes should not be created for that columns for which the
value in the column varies a lot.

indexes should also not be created on the columns on which
high level of DML's and DDL's are performed.