1. Algorithms for Executing query
2.External sorting
3. Sort strategy
4. Merge strategy
5.Algorithm for select operation
6. Methods and Implementation of join operation
7. Indexing methods for efficient access
8. Query optimization techniques
9. Data compression techniques
10. Parallel processing algorithms
11. Query caching and result reuse
12. Transaction management algorithms
13. Concurrency control algorithms
14. Deadlock detection and resolution algorithms
15. Backup and recovery algorithms
16. Data replication and synchronization algorithms
17. Query rewrites and transformations
18. Cost-based optimization algorithms
19. Data mining algorithms
20. Machine learning algorithms applied to database operations