What are an Index in SQL Server and all developer use indexing in the database?
What are an Index in SQL Server and all developer use indexing in the database?
Ask by Ravi Vishwakarma
Updated 22 Sep 2021
SQL INDEX:
SQL Create Index statement is used to create Indexes in database table. Indexes are used to retrieve data from database table more quickly than other ways. The user can not see indexes they just used it to speedup searches/queries.
Updating a table with indexes take more time than update table without indexes because indexes also need to update, so index only created on column that will be searches frequently.
There are also duplicated values are allowed in the index.
Syntax for Create Index-
Create Unique Index:
When create unique index on a table it does not allowed duplicate values.
Syntax-
Example:
Lets take a database table ‘Student’
Now, create an Syntax on above table like as,
To create index on multiple column in a table the following SQL statement is used. It created on other database table ‘StudentRecord;.
DELETE Index:
Example: