2026-03-12 21:01:38

tiddlywiki/RAT example.md

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+[Original article](https://blog.yannickjaquier.com/oracle/database-replay-by-example.html)
+
+
+Setup user workload
+-------------------
+
+	create user XIZOR identified by secret;
+	grant connect, resource to XIZOR;
+	grant unlimited tablespace to XIZOR;
+
+	connect XIZOR/secret
+
+	DROP TABLE test1 purge;
+	CREATE TABLE test1(id NUMBER, descr VARCHAR(50));
+
+	-- execute 4 times in order to generate 2.000.000 lines
+
+	DECLARE
+	  i NUMBER;
+	  nbrows NUMBER;
+	BEGIN
+	  SELECT NVL(MAX(id),0) INTO i FROM test1;
+	  i:=i+1;
+	  nbrows:=i+5000000;
+	  LOOP
+	    EXIT WHEN i>nbrows;
+	    INSERT INTO test1 VALUES(i, RPAD('A',49,'A'));
+	    i:=i+1;
+	  END LOOP;
+	  COMMIT;
+	END;
+	/
+
+	select count(*) from test1;
+
+
+Setup capture environement
+--------------------------
+
+	create or replace directory dbcapture AS '/home/oracle/rat';
+ 
+Filter capture in order to catch only our user ations:
+
+	exec dbms_workload_capture.add_filter('XIZOR user','USER','XIZOR');
+
+
+	col type format a10
+	col status format a10
+	col name format a20
+	col attribute format a10
+	col value format a30
+	SET lines 150
+
+	SELECT type,status,name,attribute,value FROM dba_workload_filters;
+
+Start capture
+-------------
+
+	exec dbms_workload_capture.start_capture(name => 'XIZOR capture', dir => 'DBCAPTURE', default_action => 'EXCLUDE');
+
+
+	SET lines 150
+	col name FOR a20
+	col directory FOR a20
+	col status FOR a20
+	col filters_used FOR 999
+
+
+	SELECT id,name,directory,status,filters_used from DBA_WORKLOAD_CAPTURES;
+
+Run user worlkoad
+-----------------
+
+Run as XIZOR user:
+
+	SET serveroutput ON SIZE 999999
+	DECLARE
+	i NUMBER;
+	random_id NUMBER;
+	maxid NUMBER;
+	stmt VARCHAR2(100);
+	BEGIN
+	  SELECT NVL(MAX(id),0) INTO maxid FROM test1;
+	  FOR i IN 1..10 LOOP
+	    random_id:=ROUND(DBMS_RANDOM.VALUE(1,maxid));
+	    DBMS_OUTPUT.PUT_LINE('UPDATE test1 SET id=' || random_id || ' WHERE id=' || random_id || ';');
+	    UPDATE test1 SET id=random_id WHERE id=random_id;
+	  END LOOP;
+	  COMMIT;
+	END;
+	/
+
+
+Finish capture
+--------------
+
+	exec DBMS_WORKLOAD_CAPTURE.FINISH_CAPTURE(timeout => 0, reason => 'Load test over');
+
+Generate capture report:
+
+	SET lines 150
+	SET pagesize 1000
+	SET LONG 999999
+	SET longchunksize 150
+
+	select DBMS_WORKLOAD_CAPTURE.report(1,'HTML') from dual;
+
+
+Prepare replay environement
+---------------------------
+
+	exec DBMS_WORKLOAD_REPLAY.PROCESS_CAPTURE('DBCAPTURE'); 
+	exec DBMS_WORKLOAD_REPLAY.INITIALIZE_REPLAY(replay_name => 'XIZOR replay', replay_dir => 'DBCAPTURE'); 
+
+
+	SET lines 150
+	col name FOR a20
+	col directory FOR a20
+	col status FOR a20
+
+	select id,name,directory,status from dba_workload_replays;
+
+
+	exec DBMS_WORKLOAD_REPLAY.PREPARE_REPLAY();
+
+Calibrate replay:
+
+	wrc replaydir=/home/oracle/rat mode=calibrate
+
+(optional) change structure
+---------------------------
+
+Before running the replay we will change the structure on database in order to generate a real difference between capture and replay scenario:
+
+	create index test1_idx_id ON test1(id);
+	exec dbms_stats.gather_table_stats('XIZOR','TEST1');
+
+
+Replay
+------
+
+Create a user for RAT replay:
+
+	create user rat_user identified by secret;
+	
+
+	create role rat_role;
+	grant create session to rat_role;
+	grant execute on dbms_workload_capture to rat_role;
+	grant execute on dbms_workload_replay to rat_role;
+	grant create session to rat_role;
+	grant create any directory to rat_role;
+	grant select_catalog_role to rat_role;
+	grant execute on dbms_workload_repository to rat_role;
+	grant administer sql tuning set to rat_role;
+	grant oem_advisor to rat_role;
+	grant create job to rat_role;
+	grant become user to rat_role;
+
+
+	grant rat_role to rat_user;
+
+
+Start worker client:
+
+	wrc rat_user/secret replaydir=/home/oracle/rat
+
+Start the replay:
+
+	exec DBMS_WORKLOAD_REPLAY.START_REPLAY();
+
+Check replay status and wait until status is *COMPLTED*:
+
+	SET lines 150
+	col name FOR a20
+	col directory FOR a20
+	col status FOR a20
+
+	select id,name,directory,status from dba_workload_replays;
+
+
+Generate reply report
+---------------------
+
+Identify the *ID* of the replay and generate the report:
+
+	SET lines 150
+	SET pagesize 1000
+	SET LONG 999999
+	SET longchunksize 150
+
+	SELECT dbms_workload_replay.report(1,'HTML') FROM dual;