Questions from Database Management

Q: Explain how referential integrity is established in databases that are SQL:

Explain how referential integrity is established in databases that are SQL:1999 compliant. Explain how the ON UPDATE RESTRICT, ON UPDATE CASCADE, and ON UPDATE SET NULL clauses differ from one another...

Q: Explain the purpose of indexing in database implementation.

Explain the purpose of indexing in database implementation.

Q: What are the potential consequences of inappropriate indexing decisions?

What are the potential consequences of inappropriate indexing decisions?

Q: In this chapter, we described four important data models and their

In this chapter, we described four important data models and their properties: enterprise, conceptual, logical, and physical. In the following table, summarize the important properties of these data m...

Q: Explain the factors to be considered in deciding whether to create an

Explain the factors to be considered in deciding whether to create an index for a column in SQL.

Q: Explain and provide at least one example of how to qualify the

Explain and provide at least one example of how to qualify the ownership of a table in SQL. What has to occur for one user to be allowed to use a table in a database owned by another user?

Q: How is the order in which attributes appear in a result table

How is the order in which attributes appear in a result table determined? How are the column heading labels in a result table changed?

Q: What is the difference between COUNT, COUNT DISTINCT, and COUNT

What is the difference between COUNT, COUNT DISTINCT, and COUNT(*) in SQL? When will these three commands generate the same and different results?

Q: What is the evaluation order for the Boolean operators (AND,

What is the evaluation order for the Boolean operators (AND, OR, NOT) in an SQL command? How can a query writer be sure that the operators will work in a specific, desired order?

Q: If an SQL statement includes a GROUP BY clause, the attributes

If an SQL statement includes a GROUP BY clause, the attributes that can be requested in the SELECT statement will be limited. Explain that limitation.