READ Free Dumps For Oracle- 1z0-023
| Question ID 8763 | Which statement about using PCTFREE and PCTUSED is true?
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| Option A | Block space utilization can be specified only at the segment level.
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| Option B | Block space utilization can be specified only in the data dictionary.
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| Option C | Block space utilization parameters can only be specified at the tablespace.
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| Option D | Block space utilization can be specified both at the tablespace level and segment level.
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| Correct Answer | A |
Explanation Explanation/Reference: Explanation: Answer A is correct. In addition to overall storage allocation for objects in the database, Oracle allows you to manage how the objects use the space they are given. Space usage is determined at the block level with the PCTFREE and PCTUSED options. Incorrect Answers: B: Block space utilization can be specified only at the segment level, not in the data dictionary. C: Block space utilization can be specified only at the segment level, not at the tablespace. D: Block space utilization can be specified at the segment level only, not at the tablespace. Oracle 8, DBA Certification Exam Guide, Jason S. Couchman, p. 350-351 Chapter 7: Managing the Physical Database Structure
| Question ID 8764 | Which type of index should be created to spread the distribution of index upon across the index tree?
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| Option A | B-tree indexes.
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| Option B | Bitmap indexes.
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| Option C | Reverse-key indexes.
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| Option D | Function-based indexes.
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| Correct Answer | C |
Explanation Explanation/Reference: Explanation: Answer C is correct. Reverse-key indexes is the same as a regular B-tree index, except one thing - the data from the column being indexed is stored in reverse order. The benefit of reverse-key indexes is that they enhance performance in Oracle Parallel Server environments because this type of index should be created to spread the distribution of index upon across the index tree. Incorrect Answers: A: B-tree index try to keep as much data as possible in the leaves of the index tree, minimizing amount of levels in index, this type of index does not distribute index upon the index tree, as reverse-key index does. B: Bitmap indexes are stored not as all other indexes in Oracle with the root-branch-leaf structure. The bitmap index stores an entry containing each distinct value, the start and the end ROWID to indicate the range of ROWIDs in this table, and a long binary string with as many bits as there are rows in the table. D: Function-based indexes is not used to distribute index upon across the index tree. Oracle 8, DBA Certification Exam Guide, Jason S. Couchman, p. 417-422 Chapter 9: Managing Database Objects I