READ Free Dumps For Oracle- 1z0-023
| Question ID 8855 | Acme Company has 32 employees who routinely access an Oracle database. On the average, each user has one active transaction at any time of the day. The DBS is attempting to create the ideal number of rollback segments for this OLTP environment. The users work in a typical OLTP environment. How many rollback segments should the DBA create?
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| Option A | One per user.
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| Option B | One per transaction.
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| Option C | 16 rollback segments.
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| Option D | Four rollback segments.
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| Option E | Eight rollback segments.
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| Correct Answer | E |
Explanation Explanation/Reference: Explanation: Answer E is correct. You need to create 8 rollback segments to handle 32 transactions in the OLTP system. There is the Rule of four to plan rollback segments numbers for OLTP systems. Take the total number of transactions that will hit the database at any given time, and divide by 4 to decide how many rollback segments to create. Incorrect Answers: A: It's just wasting of resources to keep one rollback segment for each user. B: It's not reasonable to create one rollback segment for each transaction. C: Use the Rule of four to calculate the number of rollback segments. D: Use the Rule of four to calculate the number of rollback segments. Oracle 8, DBA Certification Exam Guide, Jason S. Couchman, p. 373 Chapter 8: Managing Database Objects I
| Question ID 8856 | A transaction fails and returns an ORA-01562 indicating that there is insufficient space in the rollback segment. What are two possible causes? (Choose two)
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| Option A | There are no rollback segments online.
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| Option B | There is no room in the tablespace for the rollback segment to extend.
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| Option C | MAXEXTENTS has been reached, preventing the segment from extending.
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| Option D | The maximum number of user per rollback segment has been exceeded.
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| Correct Answer | BC |
Explanation Explanation/Reference: Explanation: Answers B and C are correct. If an ORA-01562 error is happened, it's two possibilities: there is no room in the tablespace for the rollback segment to grow or MAXEXTENTS has been reached. Incorrect Answers: A: To receive this error you need to have rollback segment online. D: There is no the maximum number of user per rollback segment value in Oracle. Oracle 8, DBA Certification Exam Guide, Jason S. Couchman, p. 380-381 Chapter 8: Managing Database Objects I