Sparse Index Files (Cont.) Compared to dense indices: Less space and less maintenance overhead for insertions and deletions. Generally slower than dense index for locating records. Good tradeoff:sparse index with an index entry for every block in file, corresponding to least search-key value in the block. data block 0 data block 1 Database System Concepts-6th Edition 11.9 ©Silberschat乜，Korth and SudarshanDatabase System Concepts - 6 11.9 ©Silberschatz, Korth and Sudarshan th Edition Sparse Index Files (Cont.) Compared to dense indices: Less space and less maintenance overhead for insertions and deletions. Generally slower than dense index for locating records. Good tradeoff: sparse index with an index entry for every block in file, corresponding to least search-key value in the block