It basically looks a SQL statement and tries to come up with a better execution plan than the one the optimizer has picked.Since it is allowed as much time as it wants to do it’s analysis, the advisor can sometimes find better approaches.Oracle Database Resource Manager (the Resource Manager) enables you to manage multiple workloads within a database that are contending for system and database resources.The following sections provide an overview of the Resource Manager: The Resource Manager helps to overcome these problems by allowing the database more control over how hardware resources are allocated.If a particular subprogram is inlined, performance almost always improves.However, because the compiler inlines subprograms early in the optimization process, it is possible for subprogram inlining to preclude later, more powerful optimizations., the PL/SQL compiler translated your source text to system code without applying many changes to improve performance.
Do not invoke a function in a query unnecessarily, and make the invocation as efficient as possible.
To always choose the best execution plan for a SQL query, Oracle relies on information about the tables and indexes in the query.
Once the optimizer has done its job, it provides an execution plan to Oracle.
Create a function-based index on the table in the query.
The If the query passes a column to a function, then the query cannot use user-created indexes on that column, so the query might invoke the function for every row of the table (which might be very large).
With the Resource Manager, you can: A resource consumer group (consumer group) is a collection of user sessions that are grouped together based on their processing needs.