Access 2003 Intermediate

SECTION 2

Indexing a Field

An index is designed to help speed up a search. When you look up something in an encyclopedia, and the subject starts with the letter Q, you are not going to start looking at A in the index! You will start at Q because you know the value is not in any of the sixteen previous letters.

The same principle applies to a database. To index a field, first view the table in Design view, like in the example from the last section of this example:

The current field, which also happens to be the primary key, is indexed. There are three options when indexing:

No	No indexing will be performed on this field
Yes (Duplicates OK)	The database will allow for multiple rows that have the same field value. VehicleID would not use this feature because it is the primary key. But if you have several rows that have the same model name, and have several different models in your database, this option makes database updates slower, but makes searches faster.
Yes (No Duplicates)	The opposite of the above feature; if you have several rows with the same make, only the first row instance will be indexed. This makes database updates faster but will decrease search time somewhat.

The only data types you can’t index are Memos, Hyperlinks, and OLE objects.