Dalí: A High Performance Main Memory Storage Manager

Abstract

Performance needs of many database appli- cations dictate that the entire database be stored in main memory. The Dali system is a main memory storage manager designed to provide the persistence, availability and safety guarantees one typically expects from a disk- resident database, while at the same time pro- viding very high performance by virtue of be- ing tuned to support in-memory data. Dali follows the philosophy of treating all data, in- cluding system data, uniformly as database files that can be memory mapped and directly accessed/updated by user processes. Direct access provides high performance; slower, but more secure, access is also provided through the use of a server process. Various features of Dali can be tailored to the needs of an ap- plication to achieve high performance - for example, concurrency control and logging can be turned off if not desired, which enables Dali to efficiently support applications that re- quire non-persistent memory resident data to be shared by multiple processes. Both object- oriented and relational databases can be im- plemented on top of Dali.