Stored Outlines on 10g as was on 9i

Question

Hi everyone,
I built lots of stored outlines in 9i for our production database. The interface to do that by then was the java client/server enterprise manager.
When I upgraded to 10g the only outlines I could find was the sql advisor from the web enterprise manager, but it do not let me customize the plans the way I did on 9i.
I found out to be a packaged called dbms_sqltune, I wasn't able to do much with that package its kinda a way complex and less pratical.
How do I create a stored outlines on 10g?
Many will ask why to force a execution plan as the optimizer is very good? Well, in my experience sometimes the optimizer just don't know "business rules" enought to find the best execution plan for a report, he can guess on the cardinality of the columns but he can't guess that if a report is build to sales dept. then they will only use the 1000 and 1005 contracts on 99% of the cases that will represent a very small part of a huge table. To complete the scenario, many vendors do not open the code for us to "hint" their queries, so stored outlines was the way to go on those (many on my case) cases.
Thanks in advance for comments!
Ricardo Rodriguez

Answer 1

Ricardo,
Allow me to say a few words as I read your question just now.
Stored outlines will do exactly what you mentioned.Stored outlines are used to make sure that optimizer wont go for another plan from what you had opted.That's the basic goal in making and conceptulating outlines.The same concept is also there in 11g with Sql Plan Baselines.Therefore, stored outlines and SQL plan baselines are used to:
- ensure that a given execution plan is always used
- do SQL tuning without changing the code of the application
Stored outlines are indeed there in 10g.Please see this line here for 10gR2,
http://download.oracle.com/docs/cd/B19306_01/server.102/b14211/outlines.htm#sthref1341
Now in the EM,there is no option(atleast I havenot seen one) to create them as the idea to use stored outlines never really got so popular.I agree those who use it,they like it very much but on a generic part, they were actualy a problem.Too many restrictions are there to implement and use them.
In 10g, this funcionality seems to be missing, you cannot 'hand made' a exection plan for the query anymore, you could just click on the advice of the sql advisor and pray to him find an solution.
In 10g the concept is enhanced a step further.Its always a bad idea to "hard-code" a plan for optimizer taking away its decision making sense.So Oracle is promoting for the same reasons which were there for outlines i.e. the query is a part of vendor application,you don't want to chance n number of parameters to tune one query only,they formulated stored profiles to do the job which does the same job but doesn't hard code the plan.SQL profiles are designed to provide to the query optimizer the information like:
- execution environment (e.g. optimizer mode)
- object statistics
- corrections related to the estimations performed by the query optimizer
As you can see, the aim of a SQL profile is "only" to change the environment in which the query optimizer works. The idea is that by changing the environment the query optimizer should be able to generated a more efficient execution plan.
I guess you would be clear with the part now.I wont even sya that outlines store the plan itself.Stored outlines, SQL plan baselines and SQL profile do not plans. They store hints which can be used to make up a plan.Yes the option in 10g from GUI is to just create Stored Profiles but not Stored Outlines which stands as a manualy done task.
Just my 2 cents on the topic.
Aman....