Explain the distinctions among the terms primary key, candidate key, and superkey.
Answer to relevant QuestionsConstruct an E-R diagram for a car-insurance company whose customers own one or more cars each. Each car has associated with it zero to any number of recorded accidents.Design an E-R diagramfor keeping track of the exploits of your favourite sports team. You should store thematches played, the scores in eachmatch, the players in each match and individual player statistics for each match. ...When designing an E-R diagram for a particular enterprise, you have several alternatives from which to choose.a. What criteria should you consider in making the appropriate choice?b. Design three alternative E-R diagrams to ...Explain the distinction between total and partial constraints. Consider the relational database of Figure, where the primary keys are underlined. Give an expression in the relational algebra to express each of the following queries:a. Find the names of all employees who work for First ...
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