If this is your first visit, be sure to check out the FAQ by clicking the link above. You may have to register before you can post: click the register link above to proceed. To start viewing messages, select the forum that you want to visit from the selection below.

Go Back  dBforums > General > Database Concepts & Design > How to decompose table with reference to Heath's Theorem? [Homework]

LinkBack Thread Tools Search this Thread Display Modes
  #1 (permalink)  
Registered User
Join Date: Nov 2008
Posts: 19
How to decompose table with reference to Heath's Theorem? [Homework]

Hi Everybody,

I'm having trouble with a certain aspect of a worksheet that I have for my DBA module. Any advice would be greatly appreciated, thanks.

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 ?
Reply With Quote

heaths theorem, homework, non-loss decomposition

Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is Off
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On