GKD-Base完整性约束的实现

Realization of GKD-Base Integrity Constraint

GKD-Base完整性约束实现方案,分为编译和执行两个独立阶段。前者从CreateTable或AlterTable语句中获取约束的信息并存入数据字典,后者则负责从数据字典中取出约束的信息,再按照这些信息对DML语句进行完整性约束的检查,以判断DML语句的合法性。其关键技术在于索引查找和内存控制。该方案包括CHECK约束及参照约束的实现。

The realization of GKD-Base is composed of compiling and executing, and the two parts re are independent. The integrity constraint information was adopted from Create table or Alter table statements and stored in data dictionary by the former; the integrity constraint information was taken from data dictionary by the later, then according to the information, the integrity constraint examinations were done while executing DML statement. The index search and memory control were the key technology. This project includes the realization of CHECK constraint and References constraint.