Answer Happy

Note dynamic statistics usedi dynamic sanpling (level-2) 1. Look at the EXPLAIN PLAN for each Query and describe what you see regarding the number of rows, the cost and the difference between merge join cartesian and hash join. 2. List the following for each of the 2 queries: Look at the top row and compare Query1 and Query 2: SELECT STATEMENT top row a. Number of rows in the result (compare Query 1 and Query 2) b. Total Bytes (compare Query 1 and Query 2) c. Total Cost (compare Query 1 and Query 2) the following 2 Queries, Insert TWO screen shots of the explain plans, one for each query n answer question 3 and 4 Query 1: SELECT A. aName FROM Athlete A, Competes Cl, Competes c2 WHERE A.aID = Cl.aID MND A,aID = C2.aID AND Cl.eID ∠C2. CID; Query 2: SELECT DISTINCT A. aName BRON Athlete A, Competes Cl, Competes C2 WHERE A.aID = C1.aID AND A.aID = C2.aID AND Cl.eID ⇔C2.eID; 3. Look at the EXPLAIN PLAN for each Query and describe what you see regarding the number of rows.
4. List the following for each of the 2 queries: Look at the top row and compare Query1 and Query 2: SELECT STATEMENT top row d. Number of rows in the result (compare Query 1 and Query 2) e. Total Bytes (compare Query 1 and Query 2) a. Total Cost (compare Query 1 and Query 2)