READ Free Dumps For Oracle- 1z0-023
| Question ID 8857 | Which two data dictionary views would you query to investigate space usage in a tablespace? (Choose two)
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| Option A | DBA_TABLES
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| Option B | DBA_EXTENTS
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| Option C | DBA_TABLESPACE
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| Option D | DBA_FREE_SPACE
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| Option E | DBA_SPACE_USAGE
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| Correct Answer | CD |
Explanation Explanation/Reference: Explanation: Answers C and D are correct. Dictionary views DBA_TABLESPACES and DBA_FREE_SPACE will provide information about space usage in a tablespace. Incorrect Answers: A: DBA_TABLES view shows information only about tables, not tablespaces. B: DBA_EXTENTS dictionary view provides information about extents, not about tablespaces. E: There is no DBA_SPACE_USAGE view in Oracle. Oracle 8, DBA Certification Exam Guide, Jason S. Couchman, p. 352-353 Chapter 7: Managing the Physical Database Structure
| Question ID 8858 | Two tables have a parent-child relationship that will be enforced by a primary key constraint and foreign key constraint. You would like the flexibility to insert rows in the child table before inserting rows in the parent table. What must you create to enforce the primary key constraint with a unique index?
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| Option A | Both constraints DEFERRABLE.
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| Option B | The foreign key constraints DEFERRABLE and the primary key constraint NOT DEFERRABLE.
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| Option C | Both constraints NOT DEFERRABLE, and use the SET CONSTRAINT command to defer checking of the foreign key constraint as needed.
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| Option D | Both constraints NOT DEFERRABLE, and use the ALTER SESSION command to defer checking of the foreign key constraint as needed.
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| Option E | The foreign key constraints DEFERRABLE, and use the ALTER TABLE command to defer checking of the foreign key constraint as needed.
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| Correct Answer | B |
Explanation Explanation/Reference: Explanation: Answer B is correct. To be able to insert data in the child table before inserting rows in the parent table, you must set the foreign constraints DEFERRABLE and the PRIMARY KEY for parent table as NOT DEFERRABLE. Incorrect Answers: A: PRIMARY KEY constraint for the parent table needs to be NOT DEFFERRABLE to avoid wrong data inserts. C: Foreign constraints in child table can be DEFFERRABLE in this case. SET CONSTRAINT command does not exist in Oracle. D: Foreign constraints in child table can be DEFFERRABLE in this case. ALTER SESSION command will not help to defer checking of the foreign key constraint as needed. E: PRIMARY KEY constraint for the parent table needs to be NOT DEFFERRABLE to avoid wrong data inserts. Oracle 8, DBA Certification Exam Guide, Jason S. Couchman, p. 345-348 Chapter 7: Managing the Physical Database Structure