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What is SQL plan Management in Oracle?

What is SQL plan Management in Oracle?

SQL Plan Management (SPM) provides a framework for completely transparent controlled execution plan evolution. With SPM the optimizer automatically manages execution plans and ensures only known or verified plans are used.

What is the difference between SQL profile and SQL baseline?

Think of it this way: SQL profiles give information to the optimizer to help select the best plan but don’t force the optimizer to select any specific plan. SQL plan baselines limit the optimizer plan selection to a set of accepted plans.

What is SQL profile in Oracle?

A SQL profile is a set of auxiliary information specific to a SQL statement. Conceptually, a SQL profile is to a SQL statement what statistics are to a table or index. The database can use the auxiliary information to improve execution plans. Therefore, SQL profiles just guide the optimizer to a better plan.

What is SQL profile and baseline in Oracle?

When used together with its regular inputs, a SQL profile helps the optimizer minimize mistakes and thus more likely to select the best plan. A SQL plan baseline for a SQL statement consists of a set of accepted plans. When the statement is parsed, the optimizer will only select the best plan from among this set.

How do I use SQL Management Plan?

Query the table using an unindexed column, which results in a full table scan. Identify the SQL_ID of the SQL statement by querying the V$SQL view. Use this SQL_ID to manually load the SQL plan baseline. The DBA_SQL_PLAN_BASELINES view provides information about the SQL plan baselines.

How do I view SQL profiles?

Manage SQL Profile in Oracle Database

1. Check the SQL Profile in the Database. COLUMN category FORMAT a10. COLUMN sql_text FORMAT a20.
2. Check the SQL Profile internal hint information. SELECT. a.name.
3. Create the SQL Profiles. Two ways:
4. Disable the SQL Profiles. BEGIN.

What is a SQL baseline?

Defined, a SQL Plan Baseline is a set of one or more “accepted” plans that contain hints, the plan hash value and other plan related data. In addition to the actual baseline, Oracle also maintains a SQL Plan History. A statement has had three different execution plans generated.

How do I find my SQL profile?

What is profile in database?

A database profile is a named set of parameters stored in your system registry that defines a connection to a particular database in the InfoMaker development environment. You must create a database profile for each data connection.

How do I check if a SQL baseline is used?

Here’s the basic idea:

1. run a statement that uses an index and check the plan.
2. create a Baseline on the statement using the index (using my create_baseline.
3. check the hints stored with the baseline (using my baselines_hints.
4. run the statement again and check the real plan to see that the Baseline was used.

What are the different ways in which PL SQL can run?

You can run a procedure or function interactively by: Using an Oracle tool, such as SQL*Plus. Calling it explicitly in the code of a database application, such as an Oracle Forms or precompiler application. Calling it explicitly in the code of another procedure or trigger.

How do I force a plan in Oracle?

Answer: Oracle provides many ways to force an execution plan:

1. Stored Outlines: Stored outlines will same an existing execution plan and force it to be used.
2. SQL Hints: Oracle hints are optimizer directives that can be used to force Oracle to always use the same execution plan for a SQL statement.

Which is better SQL plan or SQL profile?

Because a profile does not constrain the optimizer to any one plan, a SQL profile is more flexible than a SQL plan baseline. For example, changes in initialization parameters and optimizer statistics enable the optimizer to choose a better plan. Oracle recommends that you use SQL Tuning Advisor.

How is SQL plan management used in Oracle?

SQL plan management is a preventative mechanism that enables the optimizer to automatically manage execution plans, ensuring that the database uses only known or verified plans. SQL plan management uses a mechanism called a SQL plan baseline. A plan baseline is a set of accepted plans that the optimizer is allowed to use for a SQL statement.

Is there a relationship between SQL baseline and SQL profile?

No strict relationship exists between the SQL profile and the plan baseline. If a statement has multiple plans in a SQL plan baseline, then a SQL profile is useful because it enables the optimizer to choose the lowest-cost plan in the baseline.

How to manage SQL profiles in Oracle Enterprise Manager?

Oracle Enterprise Manager Cloud Control (Cloud Control) usually handles SQL profiles as part of automatic SQL tuning. On the command line, you can manage SQL profiles with the DBMS_SQLTUNE package.