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.
What is Auto DOP? - Oracle
Introduced in 11.2 Auto DOP enables the optimizer to calculate the DOP for a statement based on resource requirements and HW characteristics. As opposed to manual DOP it does not require table/index decorations or hints. Here is the basic decision flow for a SQL statement with Auto DOP.
Setting the Degree of Parallelism - Oracle Help Center
8.2.5 Controlling Automatic Degree of Parallelism There are several initialization parameters that control automatic degree of parallelism (auto DOP). These initialization parameters include PARALLEL_DEGREE_POLICY, PARALLEL_DEGREE_LIMIT, PARALLEL_MIN_TIME_THRESHOLD, and PARALLEL_MIN_DEGREE .
Auto DOP and Concurrency - Oracle
The goal of Auto DOP The idea behind calculating the Automatic Degree of Parallelism is to find the highest possible DOP (ideal DOP) that still scales. In other words, if we were to increase the DOP even more above a certain DOP we would see a tailing off of the performance curve and the resource cost / performance would become less optimal.
- 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.
- 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.
- 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.
- 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.
