I am reading about candidate keys and composite keys. I came to know that a candidate key can qualify as a primary key and it can be a single column or combination of columns and a composite key ...

R = (A, B, C, D, E) The functional dependencies are: A -> B ED -> A BC -> E It then lists the candidate keys as: ACD, BCD, CDE How are these candidate keys derived from the above FDs? S...

Please consider the following table definition... Table Definition CREATE TABLE [dbo].[Folders]( [Id] [int] IDENTITY(1,1) NOT NULL, [UserId] [int] NOT NULL, [ParentFolderId] [int] NULL PRIMARY...

Given a relation schema R with n attributes R(A1, A2, ..., An). What’s the maximum number of possible super-keys for R? Please justify your answer. Given a relation schema R with n attributes R(A1...

At https://web.archive.org/web/20130514174856/http://databases.about.com/cs/specificproducts/g/determinant.htm I found this by Mike Chapple: Definition: A determinant in a database table is any at...

I'm writing some software that requires storing items in a database, the items need to have a 'priority' so we end up with ID | Name | Priority --------+--------------+---------- 1 | Pear | 4 2...