View the code sequence: 
Examine the Exhibit to view the execution plan.
Which two statements are true about the query execution?
A.
The optimizer joins specified tables in the order as they appear in the FROM clause.
B.
The CUSTOMERS and ORDERS tables are joined first and the resultant is then joined with
rows returned by the ORDER_ITEMS table.
C.
The CUSTOMERS and ORDER_ITEMS tables are joined first the resultant is then joined with
rows by the ORDERS table.
D.
The optimizer has chosen hash join as an access method as the OPTIMIZER_MODE
parameter is set to FIRST_ROWS.
Explanation:
The first executed join is in line 6.
The second executed join is in line 1.
Incorrect:
A: Line 7 and 8 are executed first.
A,C correct
I’m agree with vasya: A,C is correct
D. Incorrect explanation 🙂 – “The optimizer has chosen hash join as an access method as the OPTIMIZER_MODE
parameter is set to FIRST_ROWS.” Optimizer mode was set to ALL_ROWS
i passed this exam today, good luck to anyone – there were no questions about db architecture – neither are in this dump so you can probably skip it
i had this question and got really confused:
A is not correct because first table accessed is orders
i choose C and D – I assumed that ” OPTIMIZER_MODE parameter is set to FIRST_ROWS.” is a typo(in real exam!) and it should be ALL_ROWS.
i dont know if my answer was correct or not
why not a,b?
If a is true join orders is CUSTOMERS, ORDER_ITEMS, ORDERS, so b is true and c is false
sorry a and c
🙂