Indexes that are too large to hold in memory II
Nonetheless, simple indexes should not be completely discarded:
- They allow the use of a binary search in a variable-length record file.
- If the index entries are significantly smaller than the data file records, sorting and file maintenance is faster.
- If there are pinned records in the data file, rearrangements of the keys are possible without moving the data records.
- They can provide access by multiple keys.