READ Free Dumps For Oracle- 1z0-001
| Question ID 8067 | Examine the structure of student table: Name Null Type STU ID NOT NULL NUMBER(3) NAME VARCHER2(25) ADDRESS VARCHER2(50) GRADUATION DATE Currently the table is empty. You have decided that null values should not be allowed for the NAME column.Which statement restricts NULL values from being entered into column?
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| Option A | ALTER TABLE student ADD CONSTRAINT name(NOT NULL);
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| Option B | ALTER TABLE student ADD CONSTRAINT NOT NULL (name);
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| Option C | ALTER TABLE student MODIFY CONSTRAINT name(NOT NULL);
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| Option D | ALTER TABLE student MODIFY(name varcher2(25) NOT NULL);
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| Correct Answer | D |
Explanation Explanation/Reference: Explanation: Answer D is correct because this query add NOT NULL constraint to Student table Incorrect Answers: A: Incorrect ADD CONSTRAINT clause in ALTER TABLE command. B: Incorrect ADD CONSTRAINT clause in ALTER TABLE command. C: Incorrect syntax using MODIFY clause of ALTER TABLE command. There is no MODIFY CONSTRAINT clause in ALTER TABLE command. Oracle 8, DBA Certification Exam Guide, Jason S. Couchman, p. 143 Chapter 4: Creating Other Database Objects in Oracle
| Question ID 8068 | You have decided to permanently remove all the data from the STUDENT table and you need the table structure in the future. Which single command performs this?
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| Option A | DROP TABLE student;
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| Option B | TRUNCATE TABLE student;
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| Option C | DELETE* FROM student;
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| Option D | TRUNCATE TABLE student KEEP STRUCTURE;
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| Option E | DELETE* FROM student KEEP STRUCTURE
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| Correct Answer | B |
Explanation Explanation/Reference: Explanation: Answer B is correct because after truncating table you delete all data and keep table and its structure for future use. Also command TRUNCATE reset highwatermark level to zero for table. Incorrect Answers: A: This DDL operation will drop table and its structure without possibility to rollback this operation. C: This operation can be used to perform question task, but it works slowly and usually used when you need to delete NOT ALL table rows. It does not reset high water mark for table. D: Incorrect clause KEEP STRUCTURE inside TRUNCATE TABLE command. E: Incorrect clause KEEP STRUCTURE inside DELETE command. Oracle 8, DBA Certification Exam Guide, Jason S. Couchman, p. 151 Chapter 4: Creating Other Database Objects in Oracle