Refer to the exhibit.

You are responsible for improving performance for a given job. From reviewing the job dump
score, you notice that many tsort operators are inserted. Join_1 is on columns “account”,
“po_date” and “hdr_number”. Join_2 is based on “account”, “hdr_number”, “paid_date”.
Which two actions will help you improve the performance without changing the business logic?
(Select two)

A.
Insert sort stage between Join_1 and Join_2, subsort (“Don’t sort, previously sorted”) on
“account”, sort “hdr_number” and “paid_date”.

B.
Partition on “account” and “hdr_number” for all joins. Change Join_1 to join on “account”,
“hdr_number” and “po_date”. Add Add $APT_SORTJNSERTION_CHECK_ONLY to job
parameter list and set it to “True”.

C.
Partition on account and hdr_numberfor all joins. Change Join_1 to join on “account”,
“hdr_number” and “po_date”. Insert Sort between Join_1 and Join_2 and subsort (“Don’t sort
previously sorted”) on “account”.

D.
Partition on account and hdrnumber for all joins. Change Join_1 to join on “account”,
“hdrnumber” and “po_date”. Insert Sort between Join_1 and Join_2 and subsort (“Don’t sort
previously sorted”) on “account” and “hdr_number” and sort on “paid_date”.

Explanation: