Factors Influence the Decision to Create an Index on a Field - Essay Example

MS Access 2007 allows the use of indexes in a table in the same way of using the index in a book: with an intention to search the required data, Office Access 2007 works by looking up the position of the records in the index. However in some cases, for example, Access usually builds an index for the primary key for you. Factors influencing the decision to create an index on a field are given as (Microsoft, 2010; Microsoft, 2004; Rob & Cornil, 2004) The data type of the field should be Text, Number, Currency, or Date/Time.

The users of the database generally predict looking for specific values stored in the field. Users predict arranging values in the field. Users predict storing a lot of unusual values in the field. If several values in the field are similar, then the index may not considerably accelerate queries. The field comprises an extensive collection of values. The field includes plenty of null values. The table is considered large enough and most queries are anticipated to retrieve less than 2 to 4% of the overall records.

Multi-column indexes have rather definite uses, so we have to confirm their use cautiously.