new SPM control

Author: nigelbayliss

optimizer/spm_plan_control/12_2_to_19c_scripts/README.md

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+<h2>Using SQL Plan Management to Control SQL Execution Plans</h2>
+
+Based on <a href="https://blogs.oracle.com/optimizer/using-sql-plan-management-to-control-sql-execution-plans">this blog article.</a>
+
+The utility scripts are fix_all.sql and fix_spm.sql
+
+They are intended to be similar in usage to the MOS script "coe_xfr_sql_profile.sql" - but using SQL plan baselines rather than SQL profiles.
+
+You can run a simple testcase as follows:
+
+```
+$ sqlplus dbauser/password
+SQL> @@setup
+SQL> @@q --- The query will use the BOB_PK execution plan (this is the best one)
+SQL> @@test_spm --- This will force the query to use the BOB_IDX plan instead (not the best plan, but this is a demo!)
+SQL> @@q --- See the query is now using the SQL plan baseline
+SQL> @@look --- Take a look at the SQL plan baseline
+```
+
+If you are licensed, you can retireve plans from AWR or SQL tuining sets:
+
+```
+$ sqlplus dbauser/password
+SQL> @@setup
+SQL> @@awr --- Load two different plans in AWR for our SQL Statement [BOB_IDX and BOB_PK]
+SQL> @@sts --- Load BOB FULL plan into a SQL tuning set
+SQL> @@test_all --- Pick one of the plans...
+ --- BOB_PK = plan hash value 772239758
+ --- BOB_IDX = plan hash value 4251244305
+ --- BOB FULL scan = plan hash value 1006760864
+SQL> @@q --- Run the query to see the plan you chose
+SQL> @test_all --- Pick a different plan
+SQL> @@q --- Take another look at the plan
+SQL> @@look --- View SQL plan baselines
+```
+
+The scripts require Oracle Database 12c Release 2 onwards.
+
+DISCLAIMER:
+ <br/>-- These scripts are provided for educational purposes only.
+ <br/>-- They are NOT supported by Oracle World Wide Technical Support.
+ <br/>-- The scripts have been tested and they appear to work as intended.
+ <br/>-- You should always run scripts on a test instance.

optimizer/spm_plan_control/12_2_to_19c_scripts/awr.sql

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+alter system flush shared_pool;
+
+DECLARE
+ l_plans_dropped PLS_INTEGER;
+BEGIN
+ FOR REC IN (SELECT DISTINCT SQL_HANDLE FROM DBA_SQL_PLAN_BASELINES where sql_text like '%HELLO%')
+ LOOP
+ L_PLANS_DROPPED := DBMS_SPM.DROP_SQL_PLAN_BASELINE (
+ sql_handle => rec.sql_handle,
+ PLAN_NAME => NULL);
+ END LOOP;
+END;
+/
+
+REM We are going to put three alternative plans into AWR:
+REM
+REM BOB_PK - plan hash value 772239758
+REM BOB_IDX - plan hash value 4251244305
+REM BOB FULL - plan hash value 1006760864
+
+EXEC DBMS_WORKLOAD_REPOSITORY.create_snapshot;
+
+@@q
+
+declare
+ n pls_integer;
+begin
+ for i in 1..100000
+ loop
+ execute immediate 'select /* HELLO */ num from bob where id = 100' into n;
+ end loop;
+end;
+/
+
+EXEC DBMS_WORKLOAD_REPOSITORY.create_snapshot;
+
+alter index bob_pk invisible;
+
+@@q
+
+declare
+ n pls_integer;
+begin
+ for i in 1..200000
+ loop
+ execute immediate 'select /* HELLO */ num from bob where id = 100' into n;
+ end loop;
+end;
+/
+
+EXEC DBMS_WORKLOAD_REPOSITORY.create_snapshot;
+
+alter index bob_pk visible;
+alter index bob_idx visible;
+
+select /* HELLO */ num from bob where id = 100;

optimizer/spm_plan_control/12_2_to_19c_scripts/drop.sql

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+set echo on
+alter system flush shared_pool;
+
+DECLARE
+ l_plans_dropped PLS_INTEGER;
+BEGIN
+ FOR REC IN (SELECT DISTINCT SQL_HANDLE FROM DBA_SQL_PLAN_BASELINES where sql_text like '%HELLO%')
+ LOOP
+ L_PLANS_DROPPED := DBMS_SPM.DROP_SQL_PLAN_BASELINE (
+ sql_handle => rec.sql_handle,
+ PLAN_NAME => NULL);
+ END LOOP;
+END;
+/
+