Microsoft® Access® 2010 24-Hour Trainer

17

Creating Table Field Indexes

Table field indexes can be a vital component to a high-performance database application. As the number of records in a table grows, the amount of time to search for a given piece of data in that haystack of records can start to become expensive. An index can be added to a field in a database to map the records in that field, so they can be accessed more quickly by the database engine during a search. Indexes in a database system help the database engine find records by creating and sorting key fields of the index. The index helps to speed up the search by using techniques to quickly isolate the specific piece of information's location in a table. This lesson discusses how to create table field indexes using Access 2010.

LESSON SETUP

This lesson introduces Access table field indexes and discusses why, when, and how they can be used in a database application. You learn how to create indexes for a field using Access 2010.

THE ROLE OF FIELD INDEXES

As noted, table field indexes can be used to help decrease the overall search time required by ACE (the Access database engine) to find records in large tables. Fields that are indexed can be unique or may include duplicates. When an index is defined as unique, it will not allow duplicate records in the field, or combination of fields, defined in the index. You may have also noticed already, in Access, that any field designated as the primary key is automatically set to allow unique values only. Access also ...