****Answer the specific multipart question and label the part you are answering ie. part a,b,c etc.*******

Consider the relation R (A, B, C) with an index on attribute A.

a. Give an example of a query that can be answered by using the index only, without consulting the tuples in R. Provide an explain plan (or equivalent) documenting your query.

b. Give an example of a query that does not use the index. Provide an explain plan (or equivalent) documenting your query.

c. Give an example of a query that can never produce any results, regardless of the data in R. Will the query be executed or does the optimizer detect the impossible situation. Provide an explain plan (or equivalent) to support your analysis.

****Answer the specific multipart question and label the part you are answering part a,b,c etc.*******