Microsoft Dynamics Development, Extensions, and Deployment (MB6-894) Practice Exam

To improve index performance in a database, it is essential to ensure that the columns are arranged from the most granular to the least granular. This arrangement helps optimize the way data is organized and retrieved.

When columns in an index are arranged from the most granular (which usually means the most specific) to the least granular, it enables faster lookups and enhances the efficiency of queries that utilize these indexed columns. Granularity in this context refers to the level of detail of the data stored in these columns. For instance, an index on a combination of a highly specific field like "customer ID" followed by a more general field such as "customer name" allows the database engine to quickly filter down to a smaller set of records before considering the broader attributes.

In contrast, if the columns were arranged from the least granular to the most granular, the index would first filter on the broader or less specific attributes. This would likely lead to more data being processed than necessary, resulting in slower query performance as the system would have to sift through a larger dataset before narrowing down to the more specific details.

Thus, arranging the index in a manner that prioritizes granularity is a proven strategy for optimizing performance in data retrieval operations.