B*TREE Indexes improve the performance of queries that select a small percentage of rows from a table. As a general guideline, we should create indexes on tables that are often queried for less than 15% of the table's rows. This value may be higher in situations where all data can be retrieved from an index, or where the indexed columns can be used for joining to other tables.

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Detailed Information      Tutorial: How to measure Index Selectivity      Date Listed: 2005-02-06      Submitted By: iidavidii      Total Hits: 3399      Rating (270 votes)

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