Friday, 21 August 2009

Performance Tuning - Question 043

Which of the following SQL operations require sort operations? (Choose two.)

A. Creating a function-based index

B . Index creation on ordered data using the NOSORT option

C. Creating a B-Tree index on ordered data

D . ANALYZE with the DELETE STATISTICS option



Explanation:

Answer A and C: Creating a B-Tree index on sorted data will still cause a sorting operation, because the NOSORT parameter was not specified. The sort is required to get the key values into the correct order in the B-Tree. Function-based indexes also require a sort, because correct order must be built into the B-Tree.

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