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- Question
How many copies of the database schema are typically used in the redesign process?
Options- A. One
- B. Two
- C. Three
- D. Four
- Correct Answer
- Three
- 1. Before any changes to database structure are attempted one should first:
Options- A. clearly understand the current structure and contents of the database only.
- B. test any changes on a test database only.
- C. create a complete backup of the operational database only.
- D. All of the above should be done. Discuss
- 2. To drop a column that is used as a foreign key, first:
Options- A. drop the primary key.
- B. drop the table containing the foreign key..
- C. drop the foreign key constraint.
- D. All of the above must be done. Discuss
- 3. Which SQL-92 standard SQL command can be used to change a table name?
Options- A. RENAME TABLE
- B. CHANGE TABLE
- C. ALTER TABLE
- D. None of the above is correct. Discuss
- 4. The EXISTS keyword will be true if:
Options- A. any row in the subquery meets the condition only.
- B. all rows in the subquery fail the condition only.
- C. both of these two conditions are met.
- D. neither of these two conditions is met. Discuss
- 5. The data model that is produced from reverse engineering is:
Options- A. a conceptual model.
- B. an internal model.
- C. a logical model.
- D. None of the above is correct. Discuss
- 6. Changing cardinalities in a database is:
Options- A. a common database design task.
- B. a rare database design task, but does occur.
- C. a database design task that never occurs.
- D. is impossible to do, so a new database must be constructed and the data moved into it. Discuss
- 7. Which is not true of a correlated subquery?
Options- A. EXISTS/NOT EXISTS is a form of a correlated subquery.
- B. The processing of the SELECT statements is nested.
- C. They can be used to verify functional dependencies.
- D. They are very similar to a regular subquery. Discuss
- 8. The process of reading a database schema and producing a data model from that schema is known as:
Options- A. data modeling.
- B. database design.
- C. reverse engineering.
- D. None of the above is correct. Discuss
- 9. Because of the importance of making data model changes correctly, many professionals are ________ about using an automated process for database redesign.
Options- A. optimistic
- B. skeptical
- C. ambivalent
- D. None of the above is correct. Discuss
- 10. Which of the following modifications may not succeed?
Options- A. Changing a column data type from char to date
- B. Changing a column data type from numeric to char
- C. Both of the above actions should succeed.
- D. Neither of the above actions will succeed. Discuss
Database Redesign problems
Search Results
Correct Answer: All of the above should be done.
Correct Answer: drop the foreign key constraint.
Correct Answer: None of the above is correct.
Correct Answer: any row in the subquery meets the condition only.
Correct Answer: None of the above is correct.
Correct Answer: a common database design task.
Correct Answer: They are very similar to a regular subquery.
Correct Answer: reverse engineering.
Correct Answer: skeptical
Correct Answer: Changing a column data type from char to date
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