다물8

cd C:\app\owner\diag\rdbms\orcl\orcl\trace
sqlplus scott/oracle
set linesize 132
set timing on
set pages 3000
alter session set tracefile_identifier='test28';
alter session set sql_trace=true;

select a.empno, a.ename, b.dname
from big_emp1 a, big_dept1 b
where a.deptno = b.deptno;

alter session set sql_trace=false;

C:\app\owner\diag\rdbms\orcl\orcl\trace>tkprof orcl_ora_1220_test28.trc test28.txt sys=no

------------------------------
SQL> show parameter undo

NAME                                 TYPE        VALUE
------------------------------------ ----------- ---------
undo_management                      string      AUTO
undo_retention                       integer     900
undo_tablespace                      string      UNDOTBS1

desc dba_tablespaces;
select tablespace_name, retention from dba_tablespaces;
alter tablespace undotbs1 retention guarantee;

create materialized view emp_sumsal
build immediate refresh complete on commit
enable query rewrite
as
select sum(a.sal) as sum_sal, a.deptno
from emp a, dept b
where a.deptno = b.deptno
group by a.deptno;

select * from all_objects where object_name = 'EMP_SUMSAL';

drop materialized view emp_sumsal;

create materialized view emp_sumsal
build deferred  -- 추후 data  생성
as
select sum(a.sal) as sum_sal, a.deptno
from emp a, dept b
where a.deptno = b.deptno
group by a.deptno;

--? 알아서 data 가져온다.
SQL> exec dbms_mview.refresh('EMP_SUMSAL','?');

PL/SQL 처리가 정상적으로 완료되었습니다.

SQL> select * from emp_sumsal;

   SUM_SAL     DEPTNO
---------- ----------
      9400         30
     10075         20
      8750         10

- C : COMPLETE
CREATE 명령의 모든 QUERY 정의를 재실행하여 기졲 데이터를 잘라내는 작업과 마스터 테이블을 기반으로 하는 모든 데이터를 재구축하는 작업이 포함
- F : FAST
마지막 REFRESH 이후의 변경 사항을 적용하며 젂체 재구축을 수행하지는 않음
MIVEW LOG를 사용한 REFRESH : 마스터 테이블의 모든 변경사항이 로그에 기록된 후 MVIEW에 적용
ROWID 범위를 이용한 REFRESH : 싞규 행의 ROWID를 이용하여 DIRECT PATH LOAD 후 MVIEW에 적용
- ? : FORCE
COMPLETE + FAST

EXEC DBMS_MVIEW.REFRESH('EMP_SUMSAL','?');

CREATE MATERIALIZED VIEW dept_sal
BUILD IMMEDIATE -- BUILD IMMEDIATE, BUILD DEFERRED 선택.
REFRESH COMPLETE -- FORCE, COMPLETE, ?
ON COMMIT -- ON DEMAND, ON COMMIT 선택.
AS
SELECT SUM(a.sal), a.deptno
FROM emp a, dept b
WHERE a.deptno = b.deptno
GROUP BY a.deptno;

INSERT INTO EMP
( EMPNO, ENAME, JOB, MGR, HIREDATE, SAL, COMM,DEPTNO )
VALUES
( 7935, 'KIM', 'MANAGER', 7839,
TO_Date( '12/17/1980 12:00:00 오전', 'MM/DD/YYYY HH:MI:SS AM'),3000, NULL, 20);

SQL> show parameter query

NAME                                 TYPE        VALUE
------------------------------------ ----------- ------------------------------
query_rewrite_enabled                string      TRUE
query_rewrite_integrity              string      enforced

grant query rewrite to scott;
grant create materialized view to scott;

SQL> SELECT SUM(a.sal), a.deptno
  2  FROM emp a, dept b
  3  WHERE a.deptno = b.deptno
  4  GROUP BY a.deptno;

Execution Plan
----------------------------------------------------------
Plan hash value: 2006461124

----------------------------------------------------------------------------
| Id  | Operation           | Name | Rows  | Bytes | Cost (%CPU)| Time     |
----------------------------------------------------------------------------
|   0 | SELECT STATEMENT    |      |     3 |    30 |     6  (34)| 00:00:01 |
|   1 |  HASH GROUP BY      |      |     3 |    30 |     6  (34)| 00:00:01 |
|*  2 |   HASH JOIN         |      |    14 |   140 |     5  (20)| 00:00:01 |
|   3 |    TABLE ACCESS FULL| DEPT |     4 |    12 |     2   (0)| 00:00:01 |
|   4 |    TABLE ACCESS FULL| EMP  |    14 |    98 |     2   (0)| 00:00:01 |
----------------------------------------------------------------------------

Predicate Information (identified by operation id):
---------------------------------------------------

   2 - access("A"."DEPTNO"="B"."DEPTNO")

Statistics
----------------------------------------------------------
          1  recursive calls
          0  db block gets
          6  consistent gets
          0  physical reads
          0  redo size
        555  bytes sent via SQL*Net to client
        415  bytes received via SQL*Net from client
          2  SQL*Net roundtrips to/from client
          0  sorts (memory)
          0  sorts (disk)
          3  rows processed

-- OPTIMIZER_MODE가 CHOOSE인 상태에서 Analyze를 실행하지 않아 QueryRewrite가 실행되지 않음
-- OPTIMIZER_MODE가 CHOOSE일 경우는 모든 테이블을 ANALYZE
-- 또한 MVIEW를 ENABLE QUERY REWRITE 옵션으로 생성해야 함
SQL> SET AUTOTRACE OFF;
SQL> drop MATERIALIZED VIEW EMP_SUMSAL;
SQL> CREATE MATERIALIZED VIEW EMP_SUMSAL
ENABLE QUERY REWRITE
AS
SELECT SUM(a.sal), a.deptno
FROM emp a, dept b
WHERE a.deptno = b.deptno
GROUP BY a.deptno;

SQL> set autot trace
SQL> SELECT SUM(a.sal), a.deptno
  2  FROM emp a, dept b
  3  WHERE a.deptno = b.deptno
  4  GROUP BY a.deptno;

Execution Plan
----------------------------------------------------------
Plan hash value: 503417823

-------------------------------------------------------------------------------------------
| Id  | Operation                    | Name       | Rows  | Bytes | Cost (%CPU)| Time     |
-------------------------------------------------------------------------------------------
|   0 | SELECT STATEMENT             |            |     3 |    78 |     3   (0)| 00:00:01 |
|   1 |  MAT_VIEW REWRITE ACCESS FULL| EMP_SUMSAL |     3 |    78 |     3   (0)| 00:00:01 |
-------------------------------------------------------------------------------------------

Note
-----
   - dynamic sampling used for this statement (level=2)

Statistics
----------------------------------------------------------
          5  recursive calls
          0  db block gets
          8  consistent gets
          0  physical reads
          0  redo size
        555  bytes sent via SQL*Net to client
        415  bytes received via SQL*Net from client
          2  SQL*Net roundtrips to/from client
          0  sorts (memory)
          0  sorts (disk)
          3  rows processed

SQL> SELECT /*+ NOREWRITE */ SUM(a.sal), a.deptno
  2  FROM emp a, dept b
  3  WHERE a.deptno = b.deptno
  4  GROUP BY a.deptno;

Execution Plan
----------------------------------------------------------
Plan hash value: 2006461124

----------------------------------------------------------------------------
| Id  | Operation           | Name | Rows  | Bytes | Cost (%CPU)| Time     |
----------------------------------------------------------------------------
|   0 | SELECT STATEMENT    |      |     3 |    30 |     6  (34)| 00:00:01 |
|   1 |  HASH GROUP BY      |      |     3 |    30 |     6  (34)| 00:00:01 |
|*  2 |   HASH JOIN         |      |    14 |   140 |     5  (20)| 00:00:01 |
|   3 |    TABLE ACCESS FULL| DEPT |     4 |    12 |     2   (0)| 00:00:01 |
|   4 |    TABLE ACCESS FULL| EMP  |    14 |    98 |     2   (0)| 00:00:01 |
----------------------------------------------------------------------------

Predicate Information (identified by operation id):
---------------------------------------------------

   2 - access("A"."DEPTNO"="B"."DEPTNO")

Statistics
----------------------------------------------------------
          1  recursive calls
          0  db block gets
          6  consistent gets
          0  physical reads
          0  redo size
        555  bytes sent via SQL*Net to client
        415  bytes received via SQL*Net from client
          2  SQL*Net roundtrips to/from client
          0  sorts (memory)
          0  sorts (disk)
          3  rows processed

SQL>

http://cafe.naver.com/parkcpta/1146

INDEX 분석

20% 이상이면 성능저하 => 리빌드 필요!

SQL> create table test as select * from big_emp;
SQL> create index i_test_empno on test(empno);
SQL> select * from user_indexes where index_name = 'I_TEST_EMPNO';
SQL> ANALYZE INDEX I_TEST_EMPNO VALIDATE STRUCTURE;
SQL> SELECT (DEL_LF_ROWS_LEN/LF_ROWS_LEN)*100 BALACE FROM INDEX_STATS;
SQL> DELETE FROM TEST WHERE EMPNO > 1 AND EMPNO < 7500;
SQL> COMMIT;
SQL> ANALYZE INDEX I_TEST_EMPNO VALIDATE STRUCTURE;  INDEX 구조 분석
SQL> SELECT DEL_LF_ROWS_LEN ,LF_ROWS_LEN, (DEL_LF_ROWS_LEN/LF_ROWS_LEN)*100 BALACE FROM INDEX_STATS;
DEL_LF_ROWS_LEN LF_ROWS_LEN BALACE
--------------- ----------- --------------
103510 453512 22.8
SQL> ALTER INDEX I_TEST_EMPNO REBUILD NOLOGGING PARALLEL 2;
SQL> ANALYZE INDEX I_TEST_EMPNO VALIDATE STRUCTURE;
SQL> SELECT DEL_LF_ROWS_LEN ,LF_ROWS_LEN, (DEL_LF_ROWS_LEN/LF_ROWS_LEN)*100 BALACE FROM INDEX_STATS;
DEL_LF_ROWS_LEN LF_ROWS_LEN BALACE
--------------- ----------- --------------
0 350002 0

# flashback table : 휴지통에서 테이블 복구

[hirasvr1:/SYSTEM/oraswno_datafile/DEVDB_DATA]$sqlplus '/as sysdba'

SQL*Plus: Release 10.2.0.2.0 - Production on Mon Dec 29 15:25:04 2008

Copyright (c) 1982, 2005, Oracle. All Rights Reserved.

Connected to:
Oracle Database 10g Enterprise Edition Release 10.2.0.2.0 - 64bit Production
With the Partitioning, OLAP and Data Mining options

SQL> grant dba to hr ;

SQL> conn hr/hr
Connected.
SQL> create table emp1 (
2 ename varchar2(10),
3 id number(10)) ;

Table created.

SQL> insert into emp1 values ('aaa', 1) ;

1 row created.

SQL> insert into emp1 values ('bbb', 2) ;

1 row created.

SQL> commit ;

Commit complete.

SQL> drop table emp1 ;

Table dropped.

SQL> show recyclebin <- 문제1) 무슨 명령어?
ORIGINAL NAME RECYCLEBIN NAME OBJECT TYPE DROP TIME
---------------- ------------------------------ ------------ -------------------
EMP1 BIN$XymNUHIAK3vgRAAAAAAAAA==$0 TABLE 2008-12-29:15:26:16

SQL> purge recyclebin; <- 문제2) 무슨 명령어?

Recyclebin purged.

SQL>
SQL> show recyclebin <-- 휴지통에 아무것도 없으니깐 아무것도 안나옴 ^^
SQL>

SQL> create table emp1 (
2 ename varchar2(10),
3 id number(10)) ;

Table created.

SQL> insert into emp1 values ('aaa', 1) ;

1 row created.

SQL> insert into emp1 values ('bbb', 2) ;

1 row created.

SQL> commit ;

Commit complete.

SQL> drop table emp1 ;

Table dropped.

SQL> show recyclebin
ORIGINAL NAME RECYCLEBIN NAME OBJECT TYPE DROP TIME
---------------- ------------------------------ ------------ -------------------
EMP1 BIN$XymNUHIBK3vgRAAAAAAAAA==$0 TABLE 2008-12-29:15:33:13

SQL> flashback table emp1 to before drop;

Flashback complete.

SQL> select * from emp1 ;

ENAME ID
---------- ----------
aaa 1
bbb 2

SQL>
SQL> purge recyclebin;

Recyclebin purged.

SQL>
SQL> create table emp2 (
2 ename varchar2(10),
3 id number(10)) ;

Table created.

SQL> insert into emp2 values ('aaa', 1) ;

1 row created.

SQL> commit ;

Commit complete.

SQL> drop table emp2 purge ; <- 문제3) 무슨 명령어?

Table dropped.

SQL> show recyclebin
SQL>

SQL> create table emp3 (
2 ename varchar2(10),
3 id number(10)) ;

Table created.

SQL> insert into emp3 values ('aaa', 1) ;

1 row created.

SQL> commit ;

Commit complete.

SQL> create index index_emp3 on emp3(ename) ;

Index created.

SQL> select index_name from user_indexes where table_name = 'EMP3' ;

INDEX_NAME
------------------------------
INDEX_EMP3

SQL> drop table emp3 ;

Table dropped.

SQL> show recyclebin ;
ORIGINAL NAME RECYCLEBIN NAME OBJECT TYPE DROP TIME
---------------- ------------------------------ ------------ -------------------
EMP3 BIN$XymNUHIEK3vgRAAAAAAAAA==$0 TABLE 2008-12-29:15:55:10
SQL>
SQL> flashback table emp3 to before drop;

Flashback complete.

SQL> select * from emp3 ;

ENAME ID
---------- ----------
aaa 1

SQL> select index_name from user_indexes where table_name = 'EMP3' ;

INDEX_NAME
------------------------------
BIN$XymNUHIDK3vgRAAAAAAAAA==$0 <- 문제4) 이것은 무엇인가?

SQL> alter index "BIN$XymNUHIDK3vgRAAAAAAAAA==$0" rename to index_emp3 ; <- 문제5) 무슨 명령어?

Index altered.

SQL> select index_name from user_indexes where table_name = 'EMP3' ;

INDEX_NAME
------------------------------
INDEX_EMP3

SQL>

===========================================================================================
# flashback query : 과거 특정 시점의 데이터를 확인하고 그때로 돌아가자 ^^

-- 현제 시간과 DB 시간이 다를수 있으니, DB시간을 확인하고 DB시간에 맞춰 작업하세요 ^^

SQL> select to_char(sysdate, 'YYYY/MM/DD HH24:MI') from dual ;

SQL> select systimestamp from dual;

SYSTIMESTAMP
---------------------------------------------------------------------------
29-DEC-08 04.28.16.798523 PM +09:00

SQL> create table emp4 (
2 ename varchar2(10),
3 salary number(10)) ;

Table created.

SQL> insert into emp4 values ('namwon', 100) ;

1 row created.

SQL> commit ;

Commit complete.

SQL> select systimestamp from dual;

SYSTIMESTAMP
---------------------------------------------------------------------------
29-DEC-08 04.31.08.784948 PM +09:00

SQL> select * from emp4 ;

ENAME SALARY
---------- ----------
namwon 100

SQL> update emp4
2 set salary=500
3 where ename='namwon' ;

1 row updated.

SQL> commit ;

Commit complete.

SQL> select * from emp4 ; <- 헉, 정남원을 급여가 100만원을 줘야 하는데 실수로 500만원을 줬다. 큰일큰일 ^^

ENAME SALARY
---------- ----------
namwon 500

SQL> select * from emp4 as of timestamp to_timestamp('2008-12-29 16:31','YYYY/MM/DD HH24:MI') ;

ENAME SALARY
---------- ----------
namwon 100

SQL> select * from emp4 as of timestamp to_timestamp('2008-12-29 16:35','YYYY/MM/DD HH24:MI') ;

ENAME SALARY
---------- ----------
namwon 100

SQL> select * from emp4 as of timestamp to_timestamp('2008-12-29 16:38','YYYY/MM/DD HH24:MI') ; <- 이 시간에 실수로 update 했구나.

ENAME SALARY
---------- ----------
namwon 500

SQL> update emp4 set salary = ( select salary from emp4
2 as of timestamp to_timestamp('2008-12-29 16:31','YYYY/MM/DD HH24:MI')
3 where ename='namwon' )
4 where ename='namwon'; <- 16:31 으로 빨리 돌아가자 ^^ 남원 급여는 100만원이야.ㅋㅋ

1 row updated.

SQL> commit ;

Commit complete.

SQL> select * from emp4 ;

ENAME SALARY
---------- ----------
namwon 100 <-- 정상적으로 100만원으로 돌아갔음 ^^

SQL>

=================================================================================================

# flashback version query : 과거 특정 기간(시간, SCN)의 이력 데이터 확인 및 그시점으로 flashback

SQL> conn hr/hr
Connected.
SQL> create table emp5 (
2 ename varchar2(10),
3 salary number(10)) ;

Table created.

SQL> insert into emp5 values ('NAMWON', 100);

1 row created.

SQL> insert into emp5 values ('KING', 1000) ;

1 row created.

SQL> commit ;

Commit complete.

SQL> select * from emp5 ;

ENAME SALARY
---------- ----------
NAMWON 100
KING 1000

SQL> update emp5
2 set salary=200
3 where ename='NAMWON';

1 row updated.

SQL> update emp5
2 set salary=2000
3 where ename='KING' ;

1 row updated.

SQL> commit ;
Commit complete.

SQL> select * from emp5 ;

ENAME SALARY
---------- ----------
NAMWON 200
KING 2000

SQL> delete from emp5 ;

2 rows deleted.

SQL> commit ;

Commit complete.

SQL> select versions_startscn, versions_endscn, versions_operation, salary, ename
2 from emp5 versions between scn minvalue and maxvalue;

VERSIONS_STARTSCN VERSIONS_ENDSCN V SALARY ENAME
----------------- --------------- - ---------- ----------
968877 D 2000 KING
968877 D 200 NAMWON
967905 968877 U 2000 KING
967905 968877 U 200 NAMWON
967846 967905 I 1000 KING
967846 967905 I 100 NAMWON

6 rows selected.

SQL> alter table emp5 enable row movement ; <- rowid를 보전하지 않기 때문에 row movement 기능 활성화 되어 있어야함.

Table altered.

SQL> flashback table emp5 to scn 967846 ; <- 돌아가고 싶은 VERSIONS_STARTSCN 을 적으면 된다

Flashback complete.

SQL> select * from emp5 ;

ENAME SALARY
---------- ----------
NAMWON 100
KING 1000

SQL> flashback table emp5 to scn 967905 ;

Flashback complete.

SQL> select * from emp5 ;

ENAME SALARY
---------- ----------
NAMWON 200
KING 2000

SQL> flashback table emp5 to scn 968877 ;

Flashback complete.

SQL> select * from emp5 ;

no rows selected

SQL>

# flashback transaction query : 과거의 어떤 시간이나 SCN 사이의 존재 했던 행들의 값을 질의
트랜잭션에 의해 변화한 행들의 이력을 보여줌

SQL> conn hr/hr
Connected.

SQL> select supplemental_log_data_min from v$database;
SUPPLEME
--------
NO

SQL> alter database add supplemental log data;
Database altered.

SQL> select supplemental_log_data_min from v$database;
SUPPLEME
--------
YES

SQL> select current_scn from v$database;

CURRENT_SCN
-----------
972858

SQL> create table emp6(
2 ename varchar2(10),
3 salary number(10));

Table created.

SQL> insert into emp6 values ('NAMWON', 100) ;

1 row created.

SQL> insert into emp6 values ('KING', 1000);

1 row created.

SQL> insert into emp6 values ('ALICE', 300) ;

1 row created.

SQL> COMMIT ;

Commit complete.

SQL> update emp6
2 set salary=300
3 where ename='NAMWON' ;

1 row updated.

SQL> update emp6
2 set salary=3000
3 where ename='KING' ;

1 row updated.

SQL> commit ;

Commit complete.

SQL> delete from emp6 ;

3 rows deleted.

SQL> commit ;

Commit complete.

SQL> select versions_startscn, versions_endscn, versions_operation, salary, ename
2 from emp6 versions between scn minvalue and maxvalue;

VERSIONS_STARTSCN VERSIONS_ENDSCN V SALARY ENAME
----------------- --------------- - ---------- ----------
973006 D 300 ALICE
973006 D 3000 KING
973006 D 300 NAMWON
972999 973006 U 3000 KING
972999 973006 U 300 NAMWON
972964 973006 I 300 ALICE
972964 972999 I 1000 KING
972964 972999 I 100 NAMWON

8 rows selected.

SQL> select undo_sql from flashback_transaction_query
2 where table_name='EMP6'
3 and commit_scn between 972999 and 973006
4 order by start_timestamp desc;

UNDO_SQL
--------------------------------------------------------------------------------
insert into "HR"."EMP6"("ENAME","SALARY") values ('ALICE','300');
insert into "HR"."EMP6"("ENAME","SALARY") values ('KING','3000');
insert into "HR"."EMP6"("ENAME","SALARY") values ('NAMWON','300');
update "HR"."EMP6" set "SALARY" = '100' where ROWID = 'AAAM4tAAEAAABFEAAA';
update "HR"."EMP6" set "SALARY" = '1000' where ROWID = 'AAAM4tAAEAAABFEAAB';

SQL>

=================================================================================================

# flashback database : 전체 데이터베이스를 과거의 특정 시점으로 돌림

SQL> select flashback_on from v$database;

FLASHBACK_ON
------------------
NO

SQL> shutdown immediate
ORA-01031: insufficient privileges

SQL> exit
Disconnected from Oracle Database 10g Enterprise Edition Release 10.2.0.1.0 - Production
With the Partitioning, OLAP and Data Mining options
[oracle@oracle ~]$ sqlplus '/as sysdba'

SQL*Plus: Release 10.2.0.1.0 - Production on Mon Dec 29 23:19:13 2008

Copyright (c) 1982, 2005, Oracle. All rights reserved.

Connected to:
Oracle Database 10g Enterprise Edition Release 10.2.0.1.0 - Production
With the Partitioning, OLAP and Data Mining options

SQL> shutdown immediate
Database closed.
Database dismounted.
ORACLE instance shut down.
SQL> startup mount
ORACLE instance started.

Total System Global Area 167772160 bytes
Fixed Size 1218316 bytes
Variable Size 79694068 bytes
Database Buffers 83886080 bytes
Redo Buffers 2973696 bytes
Database mounted.
SQL> alter database flashback on ;

Database altered.

SQL> alter database open ;

Database altered.

SQL> select flashback_on from v$database;

FLASHBACK_ON
------------------
YES

SQL> alter system switch logfile ;

System altered.

SQL> select current_scn from v$database;

CURRENT_SCN
-----------
974236

SQL> drop user hr cascade ; <- 제가 젤로 아끼는 hr 유저 drop

User dropped.

SQL> conn hr/hr <- hr 유저가 drop 되서 접속 안됨 ㅠㅠ
ERROR:
ORA-01017: invalid username/password; logon denied

SQL> exit
[oracle@oracle ~]$ sqlplus '/as sysdba'

SQL*Plus: Release 10.2.0.1.0 - Production on Mon Dec 29 23:23:13 2008

Copyright (c) 1982, 2005, Oracle. All rights reserved.

Connected to:
Oracle Database 10g Enterprise Edition Release 10.2.0.1.0 - Production
With the Partitioning, OLAP and Data Mining options

SQL> shutdown immediate
Database closed.
Database dismounted.
ORACLE instance shut down.
SQL>
SQL> startup monut
SP2-0714: invalid combination of STARTUP options
SQL> startup mount
ORACLE instance started.

Total System Global Area 167772160 bytes
Fixed Size 1218316 bytes
Variable Size 88082676 bytes
Database Buffers 75497472 bytes
Redo Buffers 2973696 bytes
Database mounted.
SQL> flashback database to scn 974236 ; <- hr 유저 drop전 SCN번호 입력 (각자 환경마다 틀림 ^^)

Flashback complete.

SQL> alter database open resetlogs ;

Database altered.

SQL> conn hr/hr <- hr 유저 복원 ^^
Connected.
SQL>

====================================================================================

해답

SQL> show recyclebin <- 문제1) 무슨 명령어?
답) 휴지통 내용보기

SQL> purge recyclebin; <- 문제2) 무슨 명령어?
답) 휴지통 비우기(휴지통 삭제)

SQL> drop table emp2 purge ; <- 문제3) 무슨 명령어?
답) 테이블 drop 하면서 휴지통에도 동시에 삭제 (flashback 으로 복구 불가 ^^)

INDEX_NAME
------------------------------
BIN$XymNUHIDK3vgRAAAAAAAAA==$0 <- 문제4) 이것은 무엇인가?
답) 테이블이 삭제된후 휴지통으로 들어가면 인덱스명이 바뀐다. 그래서 원래 이름으로 rename 해야 한다 ^^

SQL> alter index "BIN$XymNUHIDK3vgRAAAAAAAAA==$0" rename to index_emp3 ; <- 문제5) 무슨 명령어?
답) 인덱스 이름 바꾸는 명령어

 AWR 구동되도록 하는 명령:

select count(*)
from scott.emp;

select *
from dba_tables
where table_name = 'EMP';

exec

dbms_stats.gather_table_stats(ownname=>'SCOTT',

tabname=>'EMP', estimate_percent=>100,

cascade=>true, degree=>1);

truncate table scott.emp;

select count(*)
from scott.emp;

select *
from dba_tables
where table_name = 'EMP';

------------------------------------------------------
cd $ORACLE_HOME/rdbms/admin/
pwd ==>
/u01/app/oracle/product/10.2.0/db_1/rdbms/admin

sqlplus '/as sysdba'
SQL>@ awrrpt.sql

http://www.xgenesis.org/scjp/

소스1:

class PingPong2 {
    synchronized void hit(long n) {
        for(int i = 1; i < 3; i++)
            System.out.print(n + "-" + i + " ");
    }
}

소스2:

public class Tester implements Runnable {
    static PingPong2 pp2 = new PingPong2();
    public static void main(String[] args) {
        new Thread(new Tester()).start();
        new Thread(new Tester()).start();
    }
    public void run() { pp2.hit(Thread.currentThread().getId()); }
}

예상 결과: n-1 n-2 n-1 n-2

실제 실행 결과 :  D:\studyjava>C:\jdk1.6.0_34\bin\java Tester
8-1 8-2 9-1 9-2