Design And Implement Of TheEmbedded Database System

The Embedded Database System is a recently rising data managing technology, which improves the development efficiency of embedded applications and the reuse potential of software codes, shortens development cycle, decreases development cost, and has considerable economy benefits. By the data location, it can be categorized as the Embedded Local Database System (ELDS) and the Embedded Network Database System (ENDS). The former stores data in embedded local equipments, and the latter in telecentres. Designing, realizing and researching into this two embedded database systems is this paper's main work topic and discussion content.ELDS is a Relational Data Base Management System, which mainly realizes effective management of local data. Its management interface adopts standard SQL92's subclass. This paper describes the realizing method at three aspects: physical layer, logical layer, and user interface layer. Besides, it devotes substantial discussion to key realizing technologies: system structure, word analysis, parsing, pretreatment technology, index system and multi-table index search. Multi-table index search is that the "select" SQL sentence for search relates to multiple tables, and, withal, theses tables have multiple indexes. This paper utilizes index the furthest by using reverse number system traversal method, which improves the search system efficiency .It is a difficulty for realization, and also a focus of discussion.ENDS includes two system structures: "HICP" network database and "XML&B/S" network system. The former mainly accesses tele-database by our independently developed HICP protocol, including "HICP" client, "HICP" protocol and "HICP" server agent as its major components. The latter is a remodel of B/S framework in embedded system, the communication data format of which is XML instead of HTML. Besides expounding these two different frameworks, this paper puts emphasis on discussion about realization technology of "HICP" server agent, which solves problems of multi-client concurrent and dead lock.Based on the above-mentioned work, aiming at the embedded local/network database System, this paper presents a new SQL search method and a real-time synchronization tactic, and expatiates on the research of the embedded network software framework and the research of the embedded integrated information system.