Indexing
Indexing is a data structure approach for retrieving records fast from a database file. A short table with only two columns is called an index. A duplicate of a table's primary or candidate key appears in the first column. The second column of the table comprises a series of pointers that carry the address of the disc block where that particular key value is stored. A primary index is a two-field, ordered file with a defined length. The first field is the same as the primary key, while the second field points to the data block in question. For each search key value in the database, a record is created in a dense index.
