Explanation:
Oracle9i will share the corresponding cursors for the two statements if you are using the rulebased optimizer or the cost-based optimizer with up-to-date statistics but with no histograms.
Incorrect Answers:
3: Oracle9i will not share the corresponding cursors if you are using the cost-based optimizer with up-to-date statistics and histograms computed for the DEPARTMENT_ID column.
4: The corresponded cursors will not be shared by Oracle if you use the cost-based optimizer with up-to-date statistics and histograms computed for the DEPARTMENT_ID column and system statistics gathered.
Reference:
OCP Oracle9i Database: New Features for Administrators, Daniel Benjamin, p. 215-217
Chapter 4: Performance and Scalability Enhancements
Oracle 9i New Features, Robert Freeman, p. 57-59
Chapter 2: Oracle9i Architecture Changes

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