TimesTen is an in-memory, relational OLTP database management system with high availability. It services very well for real time application because of short response time and high throughput. TimesTen can deployed in following ways: Classic (single node), Cache and Scaleout (distributed, assume this deployment when coming to concurrency-related sections later).
TimesTen was originally named as SmallBase and developed by HP Labs. Shortly after its first commercial use in 1995, the product was split out as a separate startup company and renamed as TimesTen. In 2005, the company with 90 employees at the time was acquired by Oracle. TimesTen was then integrated with Oracle software as well as services and become part of Oracle Database Products.
Multi-version Concurrency Control (MVCC)
B+Tree Hash Table BitMap T-Tree
By default TimesTen uses B+Tree. The original version (SmallBase) from the 1990s supported T-Trees. TimesTen still supports T-Tree indexes but the administrator has to request for the DBMS to use them.