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3.5. Index Files

When a table is stored on disk, it is often referred to as a file. In this case, each row of the table is referred to as a record and each column is referred to as a field. (These terms are often used for any table.)

Since disk access is typically slow, an important goal is to reduce the amount of disk accesses necessary to retrieve the desired data from a file. Sequential searching of the data, record-by-record, to find the desired information may require a large number of disk accesses, and is very inefficient.


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