[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;