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- Question
Database redesign is not terribly difficult if the:
Options- A. database is structured.
- B. database is well-designed.
- C. database has no data.
- D. database is relatively small.
- Correct Answer
- database has no data.
- 1. What SQL command will allow you to change the table STUDENT to add the constraint named GradeCheck that states that the values of the Grade column must be greater than 0?
Options- A. ALTER TABLE STUDENT ALTER CONSTRAINT GradeCheck (Grade > 0);
- B. ALTER TABLE STUDENT ADD CONSTRAINT GradeCheck (Grade > 0);
- C. ALTER TABLE STUDENT ADD CONSTRAINT GradeCheck CHECK (Grade > 0);
- D. None of the above is correct. Discuss
- 2. 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
- 3. 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
- 4. 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
- 5. 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
- 6. After a table has been created, its structure can be modified using the SQL command:
Options- A. UPDATE TABLE [TableName].
- B. MODIFY TABLE [TableName].
- C. ALTER TABLE [TableName].
- D. CHANGE TABLE [TableName]. Discuss
- 7. What Oracle backup and recover file contains user and system data?
Options- A. Control file
- B. Datafile
- C. OnLine ReDo file
- D. Offline ReDo file Discuss
- 8. Which statement about sequences is not true?
Options- A. A sequence is an object that generates a sequential series of unique numbers.
- B. Sequences are most often used to provide values for surrogate keys.
- C. NextVal and CurrVal are both sequence methods.
- D. Sequences guarantee valid surrogate key values. Discuss
- 9. Of the three ways to create an Oracle database, which one is the easiest and most recommended?
Options- A. Using the Oracle Database Configuration Assistant.
- B. Using the Oracle-supplied database creation procedures.
- C. Using the SQL CREATE DATABASE command.
- D. None of the above is correct. Discuss
- 10. Which of the following is not true about indexes?
Options- A. Indexes are created to enforce uniqueness on columns.
- B. Indexes are created to enable fast retrieval by column values.
- C. Columns that are frequently used with equal conditions in WHERE clauses are good candidates for indexes.
- D. Indexes are created with the ALTER TABLE command. Discuss
Database Redesign problems
Search Results
Correct Answer: ALTER TABLE STUDENT ADD CONSTRAINT GradeCheck CHECK (Grade > 0);
Correct Answer: Changing a column data type from char to date
Correct Answer: skeptical
Correct Answer: reverse engineering.
Correct Answer: They are very similar to a regular subquery.
Correct Answer: ALTER TABLE [TableName].
Correct Answer: Datafile
Correct Answer: Sequences guarantee valid surrogate key values.
Correct Answer: Using the Oracle Database Configuration Assistant.
Correct Answer: Indexes are created with the ALTER TABLE command.
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