Examine the query and its execution plan: 
Which statement is true regarding the execution plan?
A.
This query first fetches rows from the CUSTOMERS table that satisfy the conditions, and then
the join return NULL from the CUSTOMER_ID column when it does not find any corresponding
rows in the ORDERS table.
B.
The query fetches rows from CUSTOMERS and ORDERS table simultaneously, and filters the
rows that satisfy the conditions from the resultset.
C.
The query first fetches rows from the ORDERS table that satisfy the conditions, and then the
join returns NULL form CUSTOMER_ID column when it does not find any corresponding rows in
the CUSTOMERS table.
D.
The query first joins rows from the CUSTOMERS and ORDERS tables and returns NULL for
the ORDERS table columns when it does not find any corresponding rows in the ORDERS table,
and then fetches the rows that satisfy the conditions from the result set.
Explanation:
A correct.
The query looks for customers which satisfy various conditions. An outer join returns NULL for the inner table columns along with the outer (preserved) table rows when it does not find any corresponding rows in the inner table. This operation finds all the customers rows that do not have any orders rows.
https://docs.oracle.com/database/121/TGSQL/tgsql_join.htm#TGSQL94989
I have cleared this exam on 16 Feb.
Do u have dumps for this?
Hello PS,Is the exam questions are same from the questions that are available in here ?
no, but all these questions and answers were useful for this exam, but we need to keep our basic rights and this is one of the toughest exam to clear, so do lots of practices on Oracle SQL Tuning and reading will help to clear it
A correct.
I passed this exam today 🙂 It was really difficult. I passed 1z0-051 score – 89%, 1z0-147 98% and 1z0-146 100 % . In this exam I got only 66%. Actually wasn’t easy. If you have any questions do not hesitate to contact me [email protected]
i passed it today with 77% 🙂 i don’t know if would passed it on first attempt without this dump altough i studied thoroughly. ( particularly when there are no official practice/sample questions)
anyone who did properly is real oracle guru!
then again, he wouldn’t be reading this 🙂
good luck to everyone
Anybody taking this exam in 2016?
i`m about to.
Also can you put links here from which you are/were learning from?
hi i have passed this exam tooday, what can i say about questions?
well, some of theme were in real exam exactly as theye are here (about 30%), others have some difference, new answers/less|more answers to choose from etc (about 20%).
And whole banch of new questions mainly about parallel coordinator, Auto DOP etc.
These dump + documentation (12c sql tunning, 11g tunning) + some books (about sql tunning) and you`r good to pass this exam 🙂
Best luck!
Anybody else taking the exam soon?
dq, can you put links on some materials that you used for preparing or name some good books?
tnx