Explanation:
The blocks transferred using the Cache Fusion algorithm in a Real Application Clusters database should be transferred across a high-speed cluster interconnect to increase the performance.
Incorrect Answers:
2: They should not be written to disk by the sending instance and read from disk by the receiving instance. Cache Fusion algorithm does not use disk read/write operations to transfer blocks.
3: It’s not possible to grant by the Global Cache Service an exclusive mode resource for EACH instance involved. Only one instance can have exclusive mode.
4: It’s not required that these blocks should be transferred through the cache area of the Global Resource Directory on the instance where the block is mastered.
Reference:
OCP Oracle9i Database: New Features for Administrators, Daniel Benjamin, p. 223-230
Chapter 4: Performance and Scalability Enhancements
Oracle 9i New Features, Robert Freeman, p. 193-206
Chapter 7: Oracle9i Real Application Clusters

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