What types of indexes are used in database management systems?

In database management systems (DBMS), several types of indexes are used to speed up data search and sorting:

• B-tree and B+-tree: the most common type of index for ordered data. Allows quick search, insertion, and deletion of records.
• Hash indexes: use hash functions for fast access based on exact key matches, but are not suitable for range queries.
• Bitmap indexes: effective for columns with a small number of unique values (e.g., gender, status).
• Full-text indexes: used for quick text search, supporting search by words and phrases.
• Spatial structure-based indexes (R-trees): used for geographic data.

The choice of index type depends on the nature of the data and the types of queries.