What is Unique Index?
- Unique index is the index that is applied to any column of a unique value.
- A unique index can also be applied to a group of columns.
- It guarantees that the index key contains no duplicate values.
- It ensures that the data integrity of the defined columns.
- It provides additional information that helps to query optimizer to produce more efficient execution plans. Syntax:
CREATE UNIQUE INDEX index_name
ON table_name (column_name);