When working with cached sequence values, which of the following is correct?
A) The cache option instructs Oracle10g to return the sequence values in the same order in which the user requests were received.
B) The cache option instructs Oracle10g not to generate any more numbers after the minimum or maximum value has been reached.
C) When a value has been generated and cached, that value has been assigned and cannot be regenerated until the sequence begins a new cycle.
D) The highest value for a cached number is 10^44.

Question

Quizplus · Accepted Answer

Option A is incorrect because the cache option affects the order in which sequence values are returned only when the ORDER option is used.
Option B is incorrect because the sequence will continue to generate numbers once the minimum or maximum value is reached, regardless of the cache option.
Option D is incorrect because the maximum value for a cached sequence is determined by the MAXVALUE parameter of the CREATE SEQUENCE statement, and the highest possible value is 10^27-1. 
Therefore, the correct option is C which states that once a value has been generated and cached, it cannot be regenerated until the sequence begins a new cycle. This is because the cache option preallocates a set of sequence values and stores them in memory to improve performance. Once a value has been assigned from the cache, it cannot be reused until the cache is exhausted or a new cycle begins.

When Working with Cached Sequence Values, Which of the Following