Post-Install Database Tasks - Oracle Exadata Recipes: A Problem-Solution Approach - page 596

All of these factors contribute to HugePages being able to improve overall performance. On Exadata, with 96 to
144 GB of physical memory and potentially large (or multiple large) SGAs, HugePages can provide a significant benefit
over normal memory sharing or Oracle Automatic Memory Management (AMM) features.

21-4. Configuring Automatic Degree of Parallelism
Problem
You intend to use parallel execution features to maximize performance and optimize system resource utilization
for the databases deployed on Exadata and you wish to optimize parallel operations by configuring Oracle 11gR2
Automatic Degree of Parallelism, or Auto DOP.

Solution
In this recipe, we will cover the basics for setting up Automatic Degree of Parallelism in your Oracle 11gR2 database.
1.

Log in to your Oracle database and seed I/O calibration data, per MOS node 1269321.1.
This step is required in order for Auto DOP to function:

SYS @ visx1> delete from resource_io_calibrate$;

1 row deleted.

SYS @ visx1> insert into resource_io_calibrate$
2 values(current_timestamp, current_timestamp, 0, 0, 200, 0, 0);

1 row created.

SYS @ visx1> commit;

Commit complete.

SYS @ visx1>

2. Set parallel_degree_policy to AUTO.

Not ■ on exadata, setting parallel_degree_policy enables parallel statement queuing as well as In-Memory
parallel execution, the latter of which could yield negative side effects. please read details in recipes 21-6 and 21-7
or the discussion in the how It Works section of this recipe for more information.

SYS @ visx1> alter system set parallel_degree_policy=AUTO scope=both sid='*';
System altered.

SYS @ visx1> alter system flush shared_pool;
System altered.
SYS @ visx1>