In a many-to-many connection relationship, there will be issues of duplicate calculations when performing aggregated calculations.
正确答案是:D: A connection relationship can be established and used for aggregated calculations。
专业分析:
1. **多维分析模型**:从图中四个表(Retail, Store, Product, Store Daily Target)来看,这些表之间存在多对多的关系,尤其是在Retail表和Store Daily Target表之间。因此,这种模型通常属于星型或雪花型模型,用于多维数据分析。
2. **表之间的连接关系**:
- **A: A connection relationship can be established, and the correspondence is many-to-many**:这是正确的。从图中可以看出,Retail表和Store Daily Target表之间可以建立多对多的连接关系。
- **B: There is more than one common field that can be used**:这是正确的,图中显示有多个共同字段可以用于连接。
- **C: After establishing a connection between the two tables, the aggregated calculation results have no practical reference significance**:这是正确的,因为多对多关系可能导致聚合计算结果失去实际意义。
- **D: A connection relationship can be established and used for aggregated calculations**:这是不正确的。由于多对多的关系,直接进行聚合计算可能会导致结果失真或无意义。
因此,选项D是不正确的,因为尽管可以建立连接关系,但由于多对多的关系,直接进行聚合计算是不合适的。