Thanks for the comments. I just updated the post with another script (gps.sql) that just prompts for the SQL_ID and adds the GATHER_PLAN_STATISTICS hint to it (via a Profile). A little more straight forward than the generic create_1_hint_sql_profile.sql script.

Kerry

I also like the idea of temporarily messing up stats to make sure they are affecting the XPLAN as expected.

A couple of more tools for my toolbox, thanks!

If a Profile exists for a given statement it should be used regardless of which user is executing the statement. There are a couple of things you can check to make sure it should be used. Look at the signature columns in v$sql and dba_sql_profiles. They should match. Also, if the statement is using the Profile, the sql_profile column in v$sql will have the name of the profile in it. If the signatures match but it’s not being picked up, that’s probably a bug. I have seen this happen with force_matching=true. So you might try without setting that option. By the way, there are many posts on this site with information on how Profiles work “under the covers”. Good luck.

Kerry

I created SQl profile through EM via advisory central using system .
Now if the same query gets executed via other user profile does not get used. How do i transfer that profile for all the users?

My dplan_allstats.sql script is just DBMS_XPLAN.DISPLAY_CURSOR with the ALLSTATS format option prompting for a sql_id and child_number (like so):

set lines 180
select * from table(dbms_xplan.display_cursor('&sql_id','&child_no','allstats'));

It won’t show the A-Rows column unless the statement was instructed to collect the extra information. This can be done by running with the GATHER_PLAN_STATISTICS hint or the session having statistics_level = all, or _rowsource_execution_statistics = true. You should get a note at bottom of the xplan output like so if you have not enabled the collection of the extended statistics.

Note
-----
   - Warning: basic plan statistics not available. These are only collected when:
       * hint 'gather_plan_statistics' is used for the statement or
       * parameter 'statistics_level' is set to 'ALL', at session or system level

Hope that helps.

Kerry

Regards,
Anand

Nice post, very informative.Where can i get dplan_allstats script?

Anand

Once a Profile has been created, its hints will be applied (as long as they are valid, and they don’t contradict each other, etc…). Since this was a simple Profile with a single directive (INDEX_RS_ASC), when that hint was found to be invalid, it went back to the Full Table Scan. The reason the hint was invalid is because an index range scan cannot be done on an index where the leading columns are not part of the predicate. A skip scan or a full index scan are possible, but not a normal range scan. And since the IGNORE_OPTIM_EMBEDDED_HINTS hint is also included in the Profile, the inline hint in the text is ignored. So basically it’s back to picking a plan without any directive hints. At least that’s what I believe is happening.

Kerry