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Anonymous Asked in Cars &Transportation · 2 weeks ago

What is a unique index?

Contents

What is unique index example?
What is the difference between an index and a unique index?
What is a unique index SQL?
What is a unique index in access?

Unique indexes are indexes that help maintain data integrity by ensuring that no rows of data in a table have identical key values. When you create a unique index for an existing table with data, values in the columns or expressions that comprise the index key are checked for uniqueness.

What is unique index example?

Multicolumn unique indexes guarantee that each combination of values in the index key is unique. For example, if a unique index is created on a combination of LastName, FirstName, and MiddleName columns, no two rows in the table could have the same combination of values for these columns.

What is the difference between an index and a unique index?

Index: It is a schema object which is used to provide improved performance in the retrieval of rows from a table. Unique Index: Unique indexes guarantee that no two rows of a table have duplicate values in the key column (or columns).

What is a unique index SQL?

SQL Server unique index overview A unique index ensures the index key columns do not contain any duplicate values. A unique index may consist of one or many columns. If a unique index has one column, the values in this column will be unique.

What is a unique index in access?

You can prevent duplicate values in a field in an Access table by creating a unique index. A unique index is an index that requires that each value of the indexed field is unique.

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