Which two actions can you make to improve the performance of theses queries?

You are administering a database that supports a DSS workload, where in an application a set of
queries use the query rewrite on materialized views. You notice that these queries are performing
poorly.
Which two actions can you make to improve the performance of theses queries?

You are administering a database that supports a DSS workload, where in an application a set of
queries use the query rewrite on materialized views. You notice that these queries are performing
poorly.
Which two actions can you make to improve the performance of theses queries?

A.
Use DBMS_MVIEW.EXPLAIN_REWRITE to analyze whether the queries are rewritten.

B.
USE DBMS_ADVISOR.QUICK_TUNE to analyze the query rewrite usage of materialized views
for the entire workload.

C.
Create an STS for all the queries and use SQL performance Analyzer to generate
recommendations for determining the regressed SQL statements.

D.
Create an STS for all the queries in the application and use the SQL Tuning Advisor to
generate recommendations.

E.
Create an STS for all the queries in the application and use the SQL Access Advisor to
generate a recommendation for optimizing materialized views for maximum query rewrite usage
and fast refresh.

Explanation:

B:
* The dbms_advisor package has a procedure called dbms_advisor.quick_tune that allows the
DBA to quickly tune a single SQL statement with a single procedure call. This procedure performs
all of the stages that are necessary to launch the SQLAccess Advisor, e.g. creating a task,
creating and populating a workload, and executing the task.
* QUICK_TUNE Procedure
This procedure performs an analysis and generates recommendations for a single SQL statement.
This provides a shortcut method of all necessary operations to analyze the specified SQL
statement. The operation creates a task using the specified task name. The task will be created
using a specified Advisor task template. Finally, the task will be executed and the results will be
saved in the repository.
Note:
* DSS – decision support system
* In tuning mode, the optimizer performs additional analysis to check whether the execution plan
produced under normal mode can be improved further. The output of the query optimizer is not an
execution plan, but a series of actions, along with their rationale and expected benefit for
producing a significantly superior plan. When running in the tuning mode, the optimizer is referred
to as the Automatic Tuning Optimizer.
Incorrect:
A: DBMS_MVIEW.EXPLAIN_REWRITE
This procedure enables you to learn why a query failed to rewrite, or, if it rewrites, which
materialized views will be used. Using the results from the procedure, you can take the
appropriate action needed to make a query rewrite if at all possible. The query specified in the
EXPLAIN_REWRITE statement is never actually executed.



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vasya_pupkin

vasya_pupkin

E should be correct, not D

Another component of the SQL Access Advisor also recommends how to optimize materialized views so that they can be fast refreshable and take advantage of general query rewrite.

Ralf

Ralf

For me A,B and E

pvd

pvd

A is not correct