Index Update:Deletion If deleted record was the only record in the file with its particular search- key value,the search-key is deleted from the index also. Single-level index deletion: Dense indices-deletion of search-key:similar to file record deletion Sparse indices- if an entry for the search key exists in the index,it is deleted by replacing the entry in the index with the next search-key value in the file (in search-key order). If the next search-key value already has an index entry,the entry is deleted instead of being replaced. Brighton A-217 Brighton 750 Mianus A-101 Downtown 500 Redwood A-110 Downtown 600 A-215 Mianus 700 A-102 Perryridge 400 A-201 Perryridge 900 A-218 Perryridge 700 A-222 Redwood 700 A-305 Round Hill 350 Database System Concepts-5th Edition,Oct 4,2006 12.11 ©Silberschat乜，Korth and SudarshanDatabase System Concepts - 5 12.11 ©Silberschatz, Korth and Sudarshan th Edition, Oct 4, 2006 Index Update: Deletion If deleted record was the only record in the file with its particular search￾key value, the search-key is deleted from the index also. Single-level index deletion: Dense indices – deletion of search-key:similar to file record deletion. Sparse indices –  if an entry for the search key exists in the index, it is deleted by replacing the entry in the index with the next search-key value in the file (in search-key order).  If the next search-key value already has an index entry, the entry is deleted instead of being replaced