Search results
Results from the WOW.Com Content Network
The columns in a candidate key are called prime attributes, [3] and a column that does not occur in any candidate key is called a non-prime attribute. Every relation without NULL values will have at least one candidate key: Since there cannot be duplicate rows, the set of all columns is a superkey, and if that isn't minimal, some subset of that ...
A marked Punchscan ballot. Full ballot (top), separated ballot (bottom). A Punchscan ballot has two layers of paper. On the top layer, the candidates are listed with a symbol or letter beside their name. Below the candidate list, there are a series of round holes in the top layer of the ballot.
A candidate key (or minimal superkey) is a superkey that can't be reduced to a simpler superkey by removing an attribute. [ 3 ] For example, in an employee schema with attributes employeeID , name , job , and departmentID , if employeeID values are unique then employeeID combined with any or all of the other attributes can uniquely identify ...
The search engine that helps you find exactly what you're looking for. Find the most relevant information, video, images, and answers from all across the Web.
Candidate's biography in 150 words or less:. Retired Navy Capt. Hung Cao came to the U.S. as a refugee from Vietnam in 1975. After a few years in West Africa, Hung moved to Virginia as a child and ...
The table's are candidate keys are: S 1 = {Court, Start time} S 2 = {Court, End time} S 3 = {Rate type, Start time} S 4 = {Rate type, End time} Only S 1, S 2, S 3 and S 4 are candidate keys (that is, minimal superkeys for that relation) because e.g. S 1 ⊂ S 5, so S 5 cannot be a candidate key.
Get AOL Mail for FREE! Manage your email like never before with travel, photo & document views. Personalize your inbox with themes & tabs. You've Got Mail!
The Foreign Key serves as the link, and therefore the connection, between the two related tables in this sample database. In a relational database, a candidate key uniquely identifies each row of data values in a database table. A candidate key comprises a single column or a set of columns in a single database table. No two distinct rows or ...