Create and change indexes

You can create indexes based on a single field or on multiple fields. Multiple-field indexes enable you to distinguish between records in which the first field may have the same value.

First open Indexes Manager window.

In the window, click the New button to create an index or double click the existing index to change its properties. A window similar to one below will show up:

Index name

Allows you to set the name for the index.

Columns

Grid that lets you choose on which columns in the table you want to create an index. It also allows you to sort the index.

Name

Allows you to specify the names of columns you want to index.

Order

It allows you to specify sorting for the index. The default sorting is Ascending.

Index Nulls

Indicates whether the column will allow null values. For more information, see Null values.

Properties

Unique

A unique index ensures that the indexed column contains no duplicate values. In the case of multicolumn unique indexes, the index ensures that each combination of values in the indexed column is unique.

Primary key

Determines whether this index will serve as a primary key for the table. You cannot have more than one primary key in a table.

Clustered

A clustered index determines the physical order of data in a table. Because the clustered index dictates the physical storage order of the data in the table, a table can contain only one clustered index. Some databases do not support clustered indexes.

Related Topics:

How to create an index

About indexes

About Indexes Manager

About primary keys

Set or change the primary key

Columns

About tables

Relationships