Best answer: How do you accept a baseline in SQL?

How do I check if a SQL baseline is used?

Displaying SQL Baseline Plans

  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 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 SQL plan baselines?

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. We can see there is a single plan associated with our baseline, which is both enabled and accepted.

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How do you create a baseline in SQL?

You can create a SQL plan baseline in several ways: using a SQL Tuning Set (STS); from the cursor cache; exporting from one database and importing into another; and automatically for every statement.

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.

What is a SQL profile?

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 difference between SQL profile and baseline?

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.

What is the difference between SQL baseline and SQL profile?

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.

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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.

What is the plan baseline?

A baseline in project management is a clearly defined starting point for your project plan. It is a fixed reference point to measure and compare your project’s progress against. This allows you to assess the performance of your project over time.

How do I copy a SQL baseline from one database to another?

To import a set of SQL plan baselines from one system to another:

  1. STEP 1) create a staging table. …
  2. STEP 2) Pack the SQL plan baselines. …
  3. STEP 3) Export the staging table. …
  4. STEP 4) Transfer the flat file to the target system. …
  5. STEP 5) Import the staging table. …
  6. STEP 6 ) Unpack the SQL plan baselines. …
  7. STEP 7) VERIFY.

How do I load a SQL baseline from AWR?

How to load sql plan baseline from AWR

  2. BEGIN. DBMS_SQLTUNE. DROP_SQLSET (sqlset_name => ‘STS_f9948h4y2aa22’); …
  3. BEGIN. DBMS_SQLTUNE.CREATE_SQLSET( sqlset_name => ‘STS_f9948h4y2aa22’, …
  4. DECLARE. cur sys_refcursor; …
  5. SELECT. first_load_time , …
  6. DECLARE. my_plans pls_integer;

What is Optimizer_adaptive_plans?


Adaptive plans are execution plans built with alternative choices that are decided at run time based on statistics collected as the query executes.

How do I disable a SQL baseline?

After the above PL/SQL block is executed, check the ENABLED column in DBA_SQL_PLAN_BASELINES View to confirm that it is disabled. (Should be set to ‘NO’); This change will prevent the optimizer from picking this plan.

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