For example, this might happen when two ore more of the tables in the MQT have a referential integrity relationship defined and the join predicate is on their primary key - foreign key columns.
例如,当MQT中的两个或多个表定义了引用完整性关系并且联结谓词在它们自己的主键-外键列上时,就会出现这种情况。
This category of overhead includes CHECK constraint verification and foreign key constraint (referential integrity (ri)) verification.
这一类的开销包括检查约束验证和外键约束(参照完整性(RI))验证。
Figure 4 depicts the referential integrity (foreign key relationship) shown by a UML association between the tables.
图4描述了由一个表之间的UML关联所表示的引用完整性(外键关系)。
This will not affect the referential integrity or primary-foreign key relationships between the tables in the membership database.
这不会影响到成员数据库中表格之间的主-外键关系。
Primary key, referential integrity, and check constraints.
主键、引用完整性和检查约束。
The Relationship Analysis results in a detailed output showing the referential integrity of key identifiers and the consistency (or redundancy) of domains. It should answer the following questions.
关系分析产生一个详细的输出,显示键标识符的引用完整性和域的一致性(或冗余)。
Ensure dependent tables in a referential integrity (ri) relationship have indexes that exactly match the foreign key.
确保参照完整性(referential integrity,ri)关系中的依赖表拥有与外键匹配的索引。
A Foreign key constraint allows you to define referential integrity between a parent and child table.
外键约束允许您定义父表和子表之间的引用完整性。
If the line appears solid, the DBMS enforces referential integrity for the relationship when rows are added or modified in the foreign-key table.
如果为实线,则当在外键表中添加或修改行时,DBMS将强制关系的引用完整性。
If the line appears dotted, the DBMS does not enforce referential integrity for the relationship when rows are added or modified in the foreign-key table.
如果为点线,则当在外键表中添加或修改行时,DBMS不强制关系的引用完整性。
Delete a foreign key constraint when you want to remove the requirement to enforce referential integrity.
如果想要移除对强制引用完整性的要求,则可删除外键约束。
Give you the option to implement referential integrity between parent and child tables by creating a foreign key constraint.
允许您选择通过创建外键约束来实现父表和子表之间的引用完整性。
A foreign key is a constraint that enforces referential integrity.
外部索引键是强制使用参考完整性的条件约束。
A foreign key constraint can implement referential integrity between parent and child tables.
外部索引键条件约束可于父资料表和子资料表之间,实作参考完整性。
A foreign key constraint allows you to define referential integrity between a parent and child table.
外部索引键条件约束可让您在父、子资料表之间定义参考整合性。
A foreign key constraint allows you to define referential integrity between a parent and child table.
外部索引键条件约束可让您在父、子资料表之间定义参考整合性。
应用推荐