Technical methods for direct access to ArcSDE vector feature model in RDBMS

In this paper, we focus on the storage schema, encoding/decoding and data compression algorithm of ArcSDE vector feature models in Relation Database Management System (RDBMS). Further, Based on ODBC database accessing techniques, we discuss systematically and implement method for direct access to the ArcSDE vector feature data which is stored in SQL Server 2000 RDBMS with the C++ programming language. Simultaneously the performance and efficiency of the direct-access technique is also analyzed and compared with ArcSDE API. The research indicates that the methods we proposed are practical and the performance is as good as the performance of ArcSDE API.