B*Tree indexes:
- Where we need to maintain the sort order of the data, making it easy to look up range data.
- Required to use multicolumn indexes, we can use the leading edge columns to resolve a query, even if that query doesn't reference all columns of the index.
- As per its behavior, its automatically stay balanced.
- Relatively constant performance of any query.
- Can also specify reverse and unique
- Recommended for OLTP databases.
Bitmapped indexes:
- Use them to index columns with that contain a relatively small number of distinct values.
- Very compact and using lesser space.
- Designed for query intensive databases.
- Not good for range scans.
- Are available only in Enterprise Edition, in relational databases only.
