Question

How do you maximize performance on a table scan?

(A) Use a parallel scan.
(B) Use a filter expression to limit the results.
(C) Use a secondary index if possible.
(D) All of the above.

Answer 1

To maximize table scan performance, it is advisable to use parallel scans, apply filter expressions to limit data, and use secondary indexes when available. Therefore, option (D) All of the above is correct.

Step-by-step explanation:

To maximize performance on a table scan, one could consider using all the options provided:

• Use a parallel scan: This approach divides the work of scanning a table across multiple threads or processes, which can significantly speed up the operation, especially on systems with multiple CPUs or cores.
• Use a filter expression to limit the results: By filtering the data, you can reduce the amount of data that needs to be processed, read, and returned by the scan operation.
• Use a secondary index if possible: Secondary indexes allow for quicker retrieval of data when you are searching based on non-primary key attributes, which can be more efficient than scanning the entire table.

So, the correct answer is (D) All of the above.