HTAP (Hybrid Transactional/Analytical Processing) databases allow both online transaction processing (OLTP) and online analytical processing (OLAP) to run simultaneously on the same data for real-time analytics. SAP HANA is an in-memory HTAP database that utilizes techniques like columnar storage and SIMD instructions to provide fast transactional processing and analytical queries on the same data. SAP HANA's lightweight locking mechanism and use of hardware transactional memory further improves the performance of OLTP workloads.