Oracle 12c offers a useful utility called the SQL Tuning Advisor. You can use this built-in tool to provide suggestions or recommendations about certain SQL statements. Although it may not always give perfect advice, just like anything else, having it in your toolbox of tuning techniques is beneficial.

• Oracle Query Performance Tuning

1. Use PL/SQL and the internal package DBMS_SQL_TUNE to create a tuning task. Type this:

   Antares autotune 5 crack mac. You should see the following:

   In the preceding command, note the TIME_LIMIT of 60. That limits the processing time to 60 seconds. You may not always want to run something like this for long periods in your database, because it incurs system overhead.

2. Execute the tuning advisor with your task by typing this:

   Because of the limit of 60 seconds provided in the task creation, this step may take up to 60 seconds to complete. During this time, your prompt won’t come back.

   When it completes, you should see this:

   If you’ve set a longer time and are getting impatient, you can open another SQL window to make sure that the task is still executing by typing

   You see something like the following:

3. When the execution is complete, you can view the results by running the BMS_SQLTUNE.report_tuning_task procedure. Type the following:

   For the sake of space, we’ve snipped some sections from the output that follows, but you see something like this:

   The latter part of the report shows the before and after execution plans. In this case, you’ve seen the before when you were generating execution plans. Go ahead and add the index, regenerate the execution plan, and see whether you’ve made an improvement.

   Before you add the index, note that the recommendations give the SQL to add the index:

   Also note that Oracle gives a warning:

4. Add the index with your own name by typing this:

   You should see something like the following:

5. Take a look at the execution plan. Type the following:

   And then type

   You should see output like this:

Now that you’ve added the index, a few things are evident:

• The cost of the plan dropped from 40336 to 5.

• There are now six steps.

• The full table scan is gone. Instead you see the use of your new index.

Often one of the tough parts about tuning a database is having a solid understanding of the application and the data. The issue might not always be obvious. Sometimes engaging other application and data experts helps.

Aug 13, 2014  If you are asking about manual sql tuning using DBMSSQLTUNE package - then use parameter timelimit of DBMSSQLTUNE.CREATETUNINGTASK procedure to control the sql tuning time. See Automatic SQL Tuning. The parameters of automatic tuning tasks could be modified using procedure DBMSAUTOSQLTUNE.SETAUTOTUNINGTASKPARAMETER. To view the current settings of auto tuning. Automatic SQL Tuning in Oracle Database 11g Release 1; Adaptive Query Optimization in Oracle Database 12c (12.1 and 12.2) EXECUTEAUTOTUNINGTASK The EXECUTEAUTOTUNINGTASK procedure and function manually initiate the SYSAUTOSQLTUNINGTASK task. The only difference between the two is the function returns the task name, which is useful if. Automatic SQL Tuning in Oracle Database 11g Release 1 As part of Automatic SQL Tuning, Oracle 11g automatically runs the SQL Tuning Advisor against high impact SQL. Sep 03, 2015  Disable and Enable Auto task Job for 11g and 12c version in Oracle Automated database maintenance tasks is used by oracle to auto tune the SQL Queries, stale stats gather and space advisory. Some time this jobs change the execution plan and caused performance issue. Following jobs is configured default by Oracle: Automatic Optimizer Statistics. End automatic SQL Tuning Advisor run for special tuning task 'SYSAUTOSQLTUNINGTASK' Changes The database was in this case moved to a different system, i.e.

Oracle Query Performance Tuning

Explain to them your findings and what you propose. They may be able to help you come to a conclusion. Also, if the data is part of a packaged third-party application, sometimes opening a ticket with the vendor is the way to go.