Configuring and Controlling Auto DOP
There are two ways to enable/disable Auto DOP, you can enable/disable it for the whole system or for a session using the initialization parameter parallel_degree_policy, or you can enable/disable it for specific SQL statements using hints. PARALLEL_DEGREE_POLICY This is the parameter used to enable/disable Auto DOP system-wise or session-wise.
Configuring and Controlling Auto DOP - Oracle
There are two ways to enable/disable Auto DOP, you can enable/disable it for the whole system or for a session using the initialization parameter parallel_degree_policy, or you can enable/disable it for specific SQL statements using hints. PARALLEL_DEGREE_POLICY This is the parameter used to enable/disable Auto DOP system-wise or session-wise.
Setting the Degree of Parallelism - Oracle Help Center
In a system that makes aggressive use of parallel execution by using a high DOP, the adaptive algorithm adjusts the DOP down when only a few operations are running in parallel. While the algorithm still ensures optimal resource utilization, users may experience inconsistent response times.
ORACLE-BASE - Auto DOP and Parallel Statement Queuing
Oracle 11g Release 2 (11.2) introduced some big changes associated with the control of parallel execution. This article gives an overview of Auto DOP and Parallel Statement Queuing, which can be used to give a degree of control over the amount of parallel execution happening on the server at any one time. The Problem; Auto DOP; Parallel
How Parallel Execution Works
The DOP for short-running queries is limited because the speedup from a very high DOP is not significant enough to justify the use of a large number of parallel servers. Example 8-1 shows how to set up consumer groups using Resource Manager to set priorities for statements in the parallel statement queue.
