2026-03-12 20:23:15

tpt/create_sql_baseline.sql

@@ -0,0 +1,66 @@
+-- Copyright 2018 Tanel Poder. All rights reserved. More info at http://tanelpoder.com
+-- Licensed under the Apache License, Version 2.0. See LICENSE.txt for terms & conditions.
+
+--------------------------------------------------------------------------------------------------------
+-- this script allows you to transfer a plan from an existing (good) cursor to the problematic (bad) one.
+-- usage:
+--
+-- @create_sql_baseline <from_good_sqlid> <good_sql_plan_hash_value> <to_bad_sqlid>
+--
+--
+-- Query baseline info from: DBA_SQL_PLAN_BASELINES
+-- Drop baselines: @drop_sql_baseline &sql_handle
+--             or: exec DBMS_SPM.DROP_SQL_PLAN_BASELINE('&sql_handle')
+--
+-- You can get the SQL_HANDLE from DBA_SQL_PLAN_BASELINES
+--
+-- More info:
+--    SQL Plan Baselines - DBMS_SPM in EE licenses 
+--      - https://jonathanlewis.wordpress.com/2011/01/12/fake-baselines/
+--    DBMS_SPM basic baseline use is included in Oracle EE in 11g+ and SE from 18c+
+--      - https://blogs.oracle.com/optimizer/does-the-use-of-sql-plan-management-and-the-dbmsspm-database-package-require-a-tuning-or-diagnostic-pack-license
+--
+--------------------------------------------------------------------------------------------------------
+SET SERVEROUT ON SIZE 1000000
+
+DEF good_sql_id  = &1
+DEF good_sql_phv = &2
+DEF bad_sql_id   = &3
+
+DECLARE
+    ret          NUMBER;
+    v_signature  NUMBER; -- hash value of normalized SQL text
+    v_sql_text   CLOB;
+    v_sql_handle VARCHAR2(100);
+BEGIN
+    ret := DBMS_SPM.LOAD_PLANS_FROM_CURSOR_CACHE('&bad_sql_id', enabled=>'NO');
+    
+    DBMS_OUTPUT.PUT_LINE(q'[Looking up SQL_ID &bad_sql_id]');
+
+    -- rownum = 1 because there may be multiple children with this SQL_ID
+    SELECT sql_fulltext, exact_matching_signature INTO v_sql_text, v_signature 
+    FROM v$sql 
+    WHERE 
+        sql_id          = '&bad_sql_id' 
+    AND rownum = 1;
+
+    DBMS_OUTPUT.PUT_LINE('Found: '||SUBSTR(v_sql_text,1,80)||'...');
+
+    DBMS_OUTPUT.PUT_LINE(q'[Signature = ]'||v_signature);
+    SELECT sql_handle INTO v_sql_handle FROM dba_sql_plan_baselines WHERE signature = v_signature AND rownum = 1;
+    DBMS_OUTPUT.PUT_LINE(q'[Handle    = ]'||v_sql_handle);
+
+    -- associate good SQL_IDs plan outline with the bad SQL_ID
+
+    ret := DBMS_SPM.LOAD_PLANS_FROM_CURSOR_CACHE(
+               sql_id => '&good_sql_id'
+             , plan_hash_value => &good_sql_phv
+             , sql_handle => v_sql_handle
+           );
+
+    DBMS_OUTPUT.PUT_LINE(q'[SQL Baseline Name = SQL_BASELINE_&1 return=]'||ret);
+END;
+/
+
+SET SERVEROUT OFF
+