(Choose two.)

Identify two effects of the DB_FILE_MULTIBLOCK_READ_COUNT parameter on the optimizer. (Choose two.)

Identify two effects of the DB_FILE_MULTIBLOCK_READ_COUNT parameter on the optimizer. (Choose two.)

A.
Decreasing the value of DB_FILE_MULTIBLOCK_READ_COUNT from the default increases the cost of index
probes for DSS workloads.

B.
A full table scan can become cheaper than index scans if the database instance has a high enough
DB_FILE MULTIBLOCK_READ_COUNT for both OLTP and DSS workloads.

C.
Increasing the value of DB_FILE_MULTIBLOCK_READ_COUNT within OS limits lowers the costing of an
index probe that is done in conjunction with a nested loop for OLTP workloads.

D.
In DSS workloads where full table scans may run in parallel and bypass the buffer cache, decreasing the
value of DB_FILE_MULTIBLOCK_READ_COUNT from the default increases the cost of full table scans.

E.
Increasing the value of DB_FILE_MULTIBLOCK_READ_COUNT within OS limits lowers the cost of full table
scans and can result in the optimizer choosing a full table scan over an index scan for both OLTP and DSS
workloads.



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