To answer this question, let's go through each option to understand why it is correct or incorrect:
Option A) For a group, output of rollup is a single record while that of scan is multiple records - This option is correct. In the context of data aggregation or summarization, the rollup operation produces a single record that represents the summary for a group. On the other hand, the scan operation produces multiple records, each representing a cumulative summary at different levels of grouping.
Option B) Rollup gives the summary for a group while scan gives cumulative summary - This option is correct. As mentioned earlier, rollup provides a summary for a group, whereas scan gives a cumulative summary. Rollup allows you to specify multiple levels of grouping, and the result is a summary that includes subtotals at each level. Scan, on the other hand, calculates cumulative summaries as it progresses through the data.
Option C) None of (i) and (ii) are true - This option is incorrect. Both (i) and (ii) are true, as explained above.
Option D) Both (i) and (ii) are true - This option is correct. Both statements in (i) and (ii) are true, as mentioned earlier.
Therefore, the correct answer is Option D. Both (i) and (ii) are true.