Complete the sentence to define a dense index.
A dense index has an index record for [1] search key value in the data file.
A dense index contains an index record for every search key value in the data file, allowing direct access to each record.
Complete the sentence to define a sparse index.
A sparse index has index records for [1] of the search key values, typically one per data block.
A sparse index contains index records for only some of the search key values, usually one per block, reducing index size but requiring block scanning.
Fix the error in the statement about sparse indexes.
Sparse indexes have an index record for [1] record in the data file.
Sparse indexes have index records for some records, not every record, to save space.
Fill both blanks to complete the comparison between dense and sparse indexes.
A dense index has [1] index records, while a sparse index has [2] index records.
A dense index has more index records because it includes every search key, while a sparse index has fewer records, indexing only some keys.
Fill all three blanks to complete the explanation of index usage.
Dense indexes provide [1] access but [2] storage space, while sparse indexes provide [3] access but save storage space.
Dense indexes provide fast access because every key is indexed, but they use more storage space. Sparse indexes save storage space but access can be slower because not every key is indexed.