The Organization And Management Of Main-Memory Data In Real-Time Main Memory Database

To satisfy the requirement of the embeded real-time application environment, the real-time database must be built on the foundation that main memory database management system is in charge of the management of main-memory data. Main memory database lay the main version of the database in the main memory, and, by a set of effective mechanisms, make sure that the database transactions derectly access the datas those are already resident in the main memory, avoiding waiting for the data I/O.This paper represents the design of the organization and management of main-memory data in the ARTs-DB real-time main memory database management system which is designed and issued by my lab. The paper consist of two parts, the management of storage space and main-memory data in the main memory.ARTs-DB system autonomously manage the storage space what is allocated by the OS. To meet the different data characters, ARTs-DB system divide the whole storage space into four areas, in the each of which a special way of space management is put into effect.In the ARTs-DB system, the database based on the relational data model, is organized in the Page-Segment model. A page in the main memory concludes several segments, corresponding to a relation in the disk. Segment is sequential storage space to store fixed-length tuples. Tuples are in differnet statuses caused by transantions accessing, so ARTs-DB updates these tuples into database in different ways.