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.
Which PL SQL packages is used to support the SQL plan management feature?
| Question ID 22024 | Which of the following PL/SQL packages is used to support the SQL plan management feature? |
|---|---|
| Option B | Utl_Com press |
| Option C | DBMS_Warning |
| Option D | DBMS_SPM |
| Correct Answer | D |
How do I create a SQL plan?
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. Let’s look at each in turn.
What is SQL plan?
A query plan (or query execution plan) is a sequence of steps used to access data in a SQL relational database management system. When a query is submitted to the database, the query optimizer evaluates some of the different, correct possible plans for executing the query and returns what it considers the best option.
Where are Oracle execution plans stored?
cursor cache
V$SQL_PLAN contains the execution plan for every statement stored in the cursor cache. Its definition is similar to the PLAN_TABLE . See “PLAN_TABLE Columns”.
How can I change SQL plan in Oracle?
Use the SQL statement below for the purpose:
- Create a test table and find good / bad SQL plans.
- Step -1: Fetch Bad Execution Plan Details.
- Step-2: Baseline the Bad SQL Explain Plan.
- Step-3: Disable the bad SQL Plan.
- Step-4: Fetch Modified SQL Plan Details.
- Step-5: Replace Execution Plan with Modified version.
What is DBA_SQL_PLAN_BASELINES?
DBA_SQL_PLAN_BASELINES displays information about the SQL plan baselines currently created for specific SQL statements.
What is baseline in Oracle 11g?
Baselines are a new feature in Oracle 11g that helps to prevent repeatedly used. SQL statements from regressing because a newly generated execution plan is less. effective than what was originally in the library cache.
How explain plan works in Oracle?
Running EXPLAIN PLAN EXPLAIN PLAN FOR SELECT last_name FROM employees; This explains the plan into the PLAN_TABLE table. You can then select the execution plan from PLAN_TABLE . This is useful if you do not have any other plans in PLAN_TABLE , or if you only want to look at the last statement.
What is SQL Tuning Advisor in Oracle?
The SQL Tuning Advisor analyzes high-volume SQL statements and offers tuning recommendations. It takes one or more SQL statements as an input and invokes the Automatic Tuning Optimizer to perform SQL tuning on the statements. It can run against any given SQL statement.
What is plan management in Oracle Database 11g?
SQL Plan Management in Oracle Database 11g Release 1. SQL plan management provides a mechanism for maintaining consistent SQL performance regardless of changes in optimizer version, optimizer statistics, schema changes, system settings and SQL profile creation.
How has Oracle SQL plan management evolved over time?
Oracle SQL plan management (also known as the execution plan or Oracle SQL Execution Plan Management) has evolved over time, as seen in these tools: Optimizer plan stability (a.k.a. stored outlines): Stored outlines were cumbersome to manage, and it was very difficult to “swap” execution plans with plan stability.
Is there only one optimal execution plan for Oracle SQL?
Within the world of Oracle SQL optimization, we see two main optimizer philosophies: those who believe that there is one and only one optimal execution plan for their SQL, and those dynamic environments that want their execution plans to change as optimizer statistics and parameters change.
What is plan management in SQL?
SQL plan management provides a mechanism for maintaining consistent SQL performance regardless of changes in optimizer version, optimizer statistics, schema changes, system settings and SQL profile creation. How Does SQL Plan Management Work? Related articles. How Does SQL Plan Management Work?