如何参照希斯定理分解表格? [家庭作业]
我对希斯定理有一个大致的了解,但我很难解决这个问题:
Use the functional dependencies to carry out a non-loss decomposition in line with Heath’s Theorem,
to produce a set of tables in 3NF (3 rd Normal Form).
Say why each decomposed table is in 3NF and no longer just 2NF
假设我有以下 FD:
{orderId} -> {employeeId, unitPrice}
这是否意味着我得到正在分解的表(父级),使用 SQL 将其转换为多个表(分解) )。从上面的结果将包括一个包含以下字段的表:
orderId, employeeId and unitPrice
为了解释 3NF 与 2NF,我是否只需确认新表中不再有任何传递依赖项。这是我对3NF要求的理解。
我如何解释上述所有与希斯定理相关的内容?
I have a general understanding of Heath Theorem but I'm having trouble getting my head around this question:
Use the functional dependencies to carry out a non-loss decomposition in line with Heath’s Theorem,
to produce a set of tables in 3NF (3 rd Normal Form).
Say why each decomposed table is in 3NF and no longer just 2NF
Say I have the following FD:
{orderId} -> {employeeId, unitPrice}
Does this mean I get the table being decomposed (parent) use SQL to convert it to multiple tables (decomposed). From the above the result would include a table with the fields:
orderId, employeeId and unitPrice
To explain 3NF vs 2NF do I just confirm there are no longer any transitive dependencies in the new table. This is my understanding of the 3NF requirement.
How do I go about explaining all of the above with relation to Heath's Theorem ?
如果你对这篇内容有疑问,欢迎到本站社区发帖提问 参与讨论,获取更多帮助,或者扫码二维码加入 Web 技术交流群。

绑定邮箱获取回复消息
由于您还没有绑定你的真实邮箱,如果其他用户或者作者回复了您的评论,将不能在第一时间通知您!
发布评论