Configuring and Controlling Auto DOP
The statement level hints PARALLEL and PARALLEL (AUTO) instruct the optimizer to use Auto DOP. The difference is that the first one uses at least a DOP of 2 whereas the second one can use serial execution depending on the optimizer's DOP computation.
Configuring and Controlling Auto DOP - Oracle
The statement level hints PARALLEL and PARALLEL (AUTO) instruct the optimizer to use Auto DOP. The difference is that the first one uses at least a DOP of 2 whereas the second one can use serial execution depending on the optimizer's DOP computation.
What is Auto DOP? - Oracle
Auto DOP relieves the burden of deciding on a DOP for each statement and enables you to focus on optimizing the whole workload together with Parallel Statement Queuing and Database Resource Manager. We will talk about how these work together in later posts.
Setting the Degree of Parallelism - Oracle Help Center
Automatic Degree of Parallelism (Auto DOP) enables Oracle Database to automatically decide if a statement should execute in parallel and what DOP it should use. The following is a summary of parallel statement processing when Auto DOP is enabled. A SQL statement is issued. The statement is parsed and the optimizer determines the execution plan.
SQL Profiles: Technical Overview - Oracle
(Auto DOP) feature. A parallel query profile is only recommended when the original plan is serial and when parallel execution can significantly reduce the elapsed time for a long-running query. When it recommends a profile that uses Auto DOP, SQL Tuning Advisor gives details
- How to configure and control auto DOP?
- Now, let's look at how you can configure and control 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.
- How to enable/disable Auto DOP in SQL Server?
- 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. This is the parameter used to enable/disable Auto DOP system-wise or session-wise.
- How do I limit the DOP computed by the optimizer with auto DOP?
- The DOP computed by the optimizer with Auto DOP can be quite high depending on the resource requirements of the statement. You can limit the DOP using the initialization parameter parallel_degree_limit or Database Resource Manager (DBRM). This parameter limits the DOP that can be computed by the optimizer.
- Does DBRM initialization parameter affect auto DOP?
- This parameter has no effect on statements not using Auto DOP. So, for any SQL statement that the optimizer decides to run in parallel with Auto DOP, it takes into account the initialization parameters, DBRM settings, system and object statistics, and HW characteristics to compute the DOP.
- What is auto DOP in SQL Server?
- For all other statements manual DOP will be used. When you set this parameter to AUTO, Auto DOP is applied to all statements regardless of the table/index DOP decorations unless those statements set a specific DOP using hints. Regardless of what you set for parallel_degree_policy you can request Auto DOP for SQL statements using the hint PARALLEL.
- What is a limited DOP parameter?
- When you set this parameter to LIMITED, Auto DOP is applied to statements accessing tables/indexes decorated with the default DOP unless those statements set a specific DOP using hints. For all other statements manual DOP will be used.
