An index is an ordered set of pointers to rows of a base table. Each index is based on the values of data in one or more table columns. An index acts like a keyed access path to optimize the retrieval of data by providing access to a table that is arranged according to the contents of key columns. These key columns provide the sequence for row retrieval. Columns that are good candidates for creating indexes are:
An index is an object that is separate from the data in the table. Once an index is created, you cannot modify it. To change the index properties, you must first drop the index and then recreate it with the appropriate changes.
You can perform the following tasks:
For more information about indexes, see Index in the SQL Reference topic in the
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