EDWBusMatrixforModelwithDimensionalBridgeTable

DW模型中的桥接表是旨在解决多对多维度的关联关系，并且它们通常扮演着连接点、角色或者属性的角色。为了处理这种情况，可以对DW总线矩阵进行修改，以便为使用桥接表的情况提供支持。

代码示例：

CREATE FACT_TABLE ( metric1 INTEGER NOT NULL, metric2 INTEGER NOT NULL, dim1_fk INTEGER NOT NULL dim2_fk INTEGER NOT NULL dim3_fk INTEGER NOT NULL, bridge_dim_fk INTEGER NOT NULL, PRIMARY KEY (dim1_fk, dim2_fk, dim3_fk, bridge_dim_fk) );

CREATE DIM_TABLE_1 ( dim1_pk INTEGER NOT NULL, dim1_attr1 VARCHAR(50) NOT NULL, dim1_attr2 VARCHAR(50) NOT NULL, PRIMARY KEY dim1_pk );

CREATE DIM_TABLE_2 ( dim2_pk INTEGER NOT NULL, dim2_attr1 VARCHAR(50) NOT NULL, dim2_attr2 VARCHAR(50) NOT NULL, PRIMARY KEY dim2_pk );

CREATE DIM_TABLE_3 ( dim3_pk INTEGER NOT NULL, dim3_attr1 VARCHAR(50) NOT NULL, dim3_attr2 VARCHAR(50) NOT NULL, PRIMARY KEY dim3_pk );

CREATE BRIDGE_DIM_TABLE ( bridge_dim_pk INTEGER NOT NULL, bridge_dim_attr1 VARCHAR(50) NOT NULL, bridge_dim_attr2 VARCHAR(50) NOT NULL, PRIMARY KEY (bridge_dim_pk) );

ALTER TABLE FACT_TABLE ADD CONSTRAINT dim1_fk FOREIGN KEY (dim1_fk) REFERENCES DIM_TABLE_1 (dim1_pk); ALTER TABLE FACT_TABLE ADD CONSTRAINT dim2_fk FOREIGN KEY (dim2_fk) REFERENCES DIM_TABLE_2 (dim2_pk); ALTER TABLE FACT_TABLE ADD CONSTRAINT dim3_fk FOREIGN KEY (dim3_fk) REFERENCES DIM_TABLE_3 (dim3_pk); ALTER TABLE FACT_TABLE ADD CONSTRAINT bridge_dim_fk FOREIGN KEY (bridge_dim_fk) REFERENCES BRIDGE_DIM_TABLE (bridge_dim_pk);

总的来说，修改EDW总线矩阵、使用桥接表和添加外键约束，可以有效处理多对多维度的关联关系。