Oracle Database Management Basic 1

ORACLE
申建忠 Frank
Oracle OCM 9i/10g/11g

Oracle&Hardware
CPUs
MEMORY
DISKs
INSTANCE
DATABASE

Oracle&OS
Background Processes
Oracle
Database
Server Processes
OracleSoftware
OS
CPUs
MEMORY
DISKs
Listener
SYSTEM Global Area
(SGA)
(PGA)
PROGRAM
Global Area
(PGA)
Oracle Server

Oracle&OS
Server Processes
PROGRAM
Global Area
(PGA)
/u02/oradata/orcl/control01.ctl
/u02/oradata/orcl/system01.dbf
/u02/oradata/orcl/sysaux01.dbf
/u02/oradata/orcl/undotbs1.dbf
/u02/oradata/orcl/temp01.dbf
/u02/oradata/orcl/users01.dbf
/u02/oradata/orcl/log01a.log
/u02/oradata/orcl/log02a.log
OracleDatabase
OracleSoftware
OS
CPUs
MEMORY
DISKs
Listener
SYSTEM Global Area
(SGA)
(PGA)
/u01/app/oracle/product/11.2.0/dbhome_1

INSTANCE
Shared Pool Buffer Cache Large Pool Java Pool Streams
Pool
SMON PMON DBWR LGWR CKPT RECO ARCH
Log Buffer
Group1
Header Header Header Header
Datafiles
Group2
Controlfile
LogFiles
Archived
logfile
ParameterFile
Password File
Alert Logfile
Trace File
DATABASE
User
Process
Server
Process
System Global Area
Program
Global
Area

Memory Type
Share for Server and Background processes
System Global Area (SGA)
Private by Server and Background processes
Program Global Area (PGA)

Automatic Memory
Management(AMM)
11g
MEMORY_MAX_TARGET
MEMORY_TARGET
SGA_TARGET + PGA_AGGREGATE_TARGET
10g
SGA_TARGET
9i
SGA_MAX_SIZE
PGA_AGGREGATE_TARGET

SGA
變動
⾃自動管理
STREAMS_POOL_SIZE
JAVA_POOL_SIZE
LARGE_POOL_SIZE
SHARED_POOL_SIZE
DB_CACHE_SIZE
⼈人為管理
DB_KEEP_CACHE_SIZE
DB_RECYCLE_CACHE_SIZE
DB_2K_CACHE_SIZE
DB_4K_CACHE_SIZE
DB_8K_CACHE_SIZE
DB_16K_CACHE_SIZE
DB_32K_CACHE_SIZE
固定
LOG_BUFFER
FIXED SGA
PGA ⾃自動管理PGA_AGGREGATE_TARGET
MEMORY_TARGET
SGA_TARGET

PGA
Large Buffer Cache
Pool
SMO
N
Shared Pool
Statistics
Java Pool
Streams
Pool
Fixed SGA Log
Buffer
Server
process
PGA
PGA
PMO
N
PGA
DBW
R
PGA
LGW
R
PGA
CKPT
PGA
ARCH
PGA
MMO
N
PGA
MMA
N
Server
process
PGA
Server
process
PGA
Server
process
PGA
Server
process
PGA
MEMORY_TARGET
PGA_AGGREGATE_TARGET SGA_TARGET
Memory
Advisors
取得
呼叫
建議
調整
Server
記錄
Parameter file
User
process
User
process
User
process
User
process
User
process

QUIZ
MEMORY_TARGET=500M and SGA_TARGET=0
MEMORY_TARGET=500M and SGA_TARGET=200M
MEMORY_TARGET=0 and SGA_TARGET=200M
MEMORY_TARGET=500M and SGA_TARGET=200M
and SHARED_POOL_SIZE=100M
MEMORY_TARGET=0 and SGA_TARGET=200M and
SHARED_POOL_SIZE=100M
MEMORY_TARGET=0 and SGA_TARGET=0 and
SHARED_POOL_SIZE=100M

STARUP Stage
SQL> ALTER DATABASE OPEN ;
SQL> ALTER DATABASE MOUNT ;
SQL> STARTUP NOMOUNT ;
SHUTDOWN
NOMOUNT
MOUNT
OPEN
SQL> STARTUP OPEN ;

Datafiles
Group1
Group2
Controlfile
LogFiles
ParameterFile
Password File
Archived
Alert Logfile logfile
Trace File
INSTANCE NOT EXISTS

NOMOUNT
Pool
Log Buffer
SMON PMON DBWR LGWR CKPT RECO ARCH VKTM
Datafiles
Group1
Group2
Controlfile
LogFiles
3.使⽤用Parameter
File開啟INSTANCE
ParameterFile
2.找到
ParameterFile
Password File
1.取得SYSDBA

Ways to get SYSDBA
OS Group Authentication
安裝Oracle軟體時指定
$ORACLE_HOME/rdbms/lib/config.c
Password File Authentication
$ORACLE_HOME/dbs/orapw$ORACLE_SID
AS SYSDBA
屬於DBA
Group
Passwo
rd File驗證密碼成
功
Insufficient
Privilege
%ORACLE_HOME%/database/pwd%ORACLE_SID%.ora
Get
Yes
SYSDBA
Yes
No
No

[oracle@oracleDB ~]$ id
uid=54321(oracle) gid=54321(oinstall) groups=54321(oinstall),54322(dba),
54323(oper),54324(asmdba),54325(asmoper),54326(asmadmin)
!
[oracle@oracleDB ~]$ cat $ORACLE_HOME/rdbms/lib/config.c
!
/* SS_DBA_GRP defines the UNIX group ID for sqldba adminstrative
access. */
/* Refer to the Installation and User's Guide for further information. */
!
/* IMPORTANT: this file needs to be in sync with
rdbms/src/server/osds/config.c, specifically regarding the
number of elements in the ss_dba_grp array.
*/
!
#define SS_DBA_GRP "dba"
#define SS_OPER_GRP "oper"
#define SS_ASM_GRP ""
!
char *ss_dba_grp[] = {SS_DBA_GRP, SS_OPER_GRP, SS_ASM_GRP};

PARAMETER FILE
$ORACLE_HOME/dbs/spfile$ORACLE_SID.ora
/u01/app/oracle/product/11.2.0/dbhome_1/dbs/spfileorcl.ora
$ORACLE_HOME/dbs/spfile.ora
$ORACLE_HOME/dbs/init$ORACLE_SID.ora
/u01/app/oracle/product/11.2.0/dbhome_1/dbs/initorcl.ora

orcl.__db_cache_size=100663296
orcl.__java_pool_size=4194304
orcl.__large_pool_size=4194304
orcl.__oracle_base='/u01/app/oracle'
orcl.__pga_aggregate_target=180355072
orcl.__sga_target=343932928
orcl.__shared_io_pool_size=0
orcl.__shared_pool_size=163577856
orcl.__streams_pool_size=4194304
*.audit_file_dest='/u01/app/oracle/admin/orcl/adump'
*.audit_trail='db'
*.compatible='11.2.0.0.0'
*.control_files='/u02/oradata/orcl/control01.ctl','/u01/app/oracle/fast_recovery_area/orcl/control02.ctl'
*.db_2k_cache_size=54525952
*.db_block_size=8192
*.db_domain=''
*.db_name='orcl'
*.db_recovery_file_dest='/u01/app/oracle/fast_recovery_area'
*.db_recovery_file_dest_size=4322230272
*.diagnostic_dest='/u01/app/oracle'
*.dispatchers='(PROTOCOL=TCP) (DISPATCHERS=2)'
*.log_archive_dest_1='location=use_db_recovery_file_dest'
*.log_archive_dest_2='location=/u02/oradata/orcl/archive1'
*.memory_target=524288000
*.open_cursors=300
*.processes=150
*.remote_login_passwordfile='EXCLUSIVE'
*.undo_tablespace='UNDOTBS1'

NOMOUNT
Pool
Log Buffer
Datafiles
Group1
Group2
Controlfile
LogFiles
MOUNT
4.使⽤用Parameter
File裡的control_files
內容得知controlfile
的位置

NOMOUNT
Pool
Log Buffer
Datafiles
Group1
Group2
Controlfile
LogFiles
MOUNT OPEN
5.由control file內容得知
datafile/logfile的位置

No/Mount Operation
NOMOUNT
Create New Database
Re-Create Controlfile
MOUNT
Change Log Mode (Noarchive<->Archive)
Recover Database
Rename filename(logfile/datafile)

SHUTDOWN Options
SQL> SHUTDOWN {NORMAL|TRANSACTIONAL|IMMEDIATE|ABORT} ;
NORMAL
TRANSACTIONAL
IMMEDIATE
ABORT

SHUTDOWN NORMAL
1.不允許新的session建⽴立。︒
2.已經連線的session不受到任何影響。︒進⾏行中的交易可以持續。︒
⽽而且當現有交易結束後，還是可以開啟新交易。︒
3.等待所有現存的session結束。︒
4.DBWR將所有Dirty buffers寫回Datafile,LGWR將Redo Entry寫
到Current Logfile Group。︒接著CKPT將checkpoint資訊(timestamp
與scn)記錄到所有的Datafile Header與Controlfile裡。︒
5.關閉Datafile與Logfile --close database
6.關閉Controlfile --dismount database
7.結束Background processes，釋放SGA所佔⽤用的記憶體。︒

SHUTDOWN
TRANSACTIONAL
2.已經連線的session不受到任何影響。︒進⾏行中的交易可以持續。︒
但當現有交易結束後，便⾃自動結束此session。︒

SHUTDOWN
IMMEDIATE
2.已經連線的session不受到任何影響。︒但進⾏行中的交易必須
Rollback。︒當現有交易完成Rollback後，此session⾃自動結束。︒

SHUTDOWN ABORT
1.直接將INSTANCE關閉。︒
2.Dirty Buffers並沒有被寫回Datafile。︒
3.Redo Entry也沒有被寫到Logfile。︒
4.有些交易尚在進⾏行中。︒

INSTANCE Recovery
ROLL FORWARD
ReCreate Dirty Buffers
Data Blocks & Undo Blocks
ROLLBACK
SHUTDOWN
Rollback Uncommitted Transactions
NOMOUNT
MOUNT
OPEN
SMON

--Alert Log內容
Completed: ALTER DATABASE MOUNT --資料庫掛載完成
Thu Apr 29 07:56:52 2010
ALTER DATABASE OPEN --準備開啟資料庫,但尚未開啟
Beginning crash recovery of 1 threads --SMON檢查是否要進⾏行Instance Recovery,
--藉由檢查儲存在Datafile Header與Controlfile的checkpoint資訊是否⼀一致.若不⼀一致則開始進⾏行Instance復原.
Started redo scan --two pass scan的first pass redo scan(由controlfile所記錄的checkpoint position開始)
Completed redo scan --checkpoint position其實是checkpoint queue裡最⽼老的Dirty buffer的Redo entry位於Logfile的位置
read 19191 KB redo, 2730 data blocks need recovery --找出需要復原的Dirty buffers個數
Started redo application at --two pass scan的second path read scan
Thread 1: logseq 17, block 44708 --redo logfile的block size=512 bytes.
--redo byte address(checkpoint position)記錄在controlfile裡(由ckpt定期更新)
Recovery of Online Redo Log: Thread 1 Group 2 Seq 17 Reading mem 0 --RollForward開始
Mem# 0: +DATA/orcl/onlinelog/group_2.262.717353923
Mem# 1: +FRA/orcl/onlinelog/group_2.258.717353927
Completed redo application of 16.43MB
Completed crash recovery at --RollForward完成
Thread 1: logseq 17, block 83091, scn 1081446
2730 data blocks read, 2729 data blocks written, 19191 redo k-bytes read
Thread 1 advanced to log sequence 18 (thread open)
Thread 1 opened at log sequence 18
Current log# 3 seq# 18 mem# 0: +DATA/orcl/onlinelog/group_3.263.717353927
Current log# 3 seq# 18 mem# 1: +FRA/orcl/onlinelog/group_3.259.717353933
Successful open of redo thread 1
MTTR advisory is disabled because FAST_START_MTTR_TARGET is not set
Thu Apr 29 07:57:10 2010
SMON: enabling cache recovery --修復bootstrap segment
Successfully onlined Undo Tablespace 9.
Verifying file header compatibility for 11g tablespace encryption..
Verifying 11g file header compatibility for tablespace encryption completed
SMON: enabling tx recovery --Rollback開始
Database Characterset is ZHT16MSWIN950
No Resource Manager plan active
SMON: Parallel transaction recovery tried
replication_dependency_tracking turned off (no async multimaster replication found)
Thu Apr 29 07:57:18 2010
Starting background process QMNC
Thu Apr 29 07:57:18 2010
QMNC started with pid=30, OS id=12191
Completed: ALTER DATABASE OPEN --資料庫開啓完成,但是Rollback操作可能還有部分尚未完成

Connection&Session
Connection
user process與server process所建⽴立的連線
IPC(Inter Processes Communication)
C/S(Client Server)
Session
server process透過user process所提供的user
name與password，建⽴立與Instance的階段作業

$ sqlplus hr/hr@192.168.56.102:1521/orcl
SQL>
!
SQL> select sid,serial#,saddr,paddr from v$session where username='HR';
!
SID SERIAL# SADDR PADDR
---------- ---------- ---------------- ----------------
29 9 000000007EA5A868 000000007E8A3DF0
!
SQL> set autotrace on
!!
SQL> select sid,serial#,saddr,paddr from v$session where username='HR';
!
---------- ---------- ---------------- ----------------
19 37 000000007EA784F8 000000007E8A3DF0
29 9 000000007EA5A868 000000007E8A3DF0
!
SQL> disconnect
SQL> connect sh/sh@192.168.56.102:1521/orcl
!
SQL> select sid,serial#,saddr,paddr from v$session where username='SH';
!
---------- ---------- ---------------- ----------------
30 63 000000007EA578C0 000000007E8A3DF0

Process Type
User Process
產⽣生SQL statement
Server Process
代表User Process執⾏行SQL statement,並回傳SELECT結果給
User Process
Background Process
必要Processes
SMON,PMON,DBWR,LGWR,CKPT,RECO
Listener Process

PMO
N
INSTANCE
orcl
orcl
DATABASE
Inter Processes Communication
User
Process
Server
Process
oracleDB
orcl.uuu.com.tw Service Name
Instance Name
Database Name
3.Session
1
2. Connection
$ export ORACLE_SID=orcl
$ export ORACLE_HOME=/u01/app/oracle/product/11.2.0/dbhome_1
$ sqlplus hr/hr
SQL>

6. Connection 7.Session
orcl.uuu.com.tw
orcl
3 4
LISTENER
PMO
N
INSTANCE
orcl
orcl
DATABASE
$ lsnrctl start LISTENER
$ORACLE_HOME/network/admin/listener.ora
User
Process
$sqlplus hr/hr@orcl
5
$ORACLE_HOME/network/admin/sqlnet.ora
NAMES.DIRECTORY_PATH=(TNSNAMES, EZCONNECT)
$ORACLE_HOME/network/admin/tnsnames.ora
Server
Process
LISTENER =
(DESCRIPTION_LIST =
(DESCRIPTION =
(ADDRESS = (PROTOCOL = IPC)(KEY = EXTPROC1521))
(ADDRESS = (PROTOCOL = TCP)(HOST = oracleDB)(PORT = 1521))
)
)
oracleDB
ORCL =
(DESCRIPTION =
(ADDRESS = (PROTOCOL = TCP)(HOST = oracleDB)(PORT = 1521))
(CONNECT_DATA =
(SERVER = DEDICATED)
(SERVICE_NAME = orcl.uuu.com.tw)
)
)
1521
Naming Method
Local Naming
orcl.uuu.com.tw Service Name
Instance Name
Database Name
1 2
Client/Server
frankMBP
Dynamic
Registration

Shared Servers
dispatchers=’(protocol=tcp)(dispatchers=2)’ shared_servers=3
PMO
N
Server
Process
Server
Process
Server
Process
Dispatcher2
Dispatcher1
user
process
user
process
user
process
user
process
server
process
Large Pool
SQL3 SQL2 SQL1
SQL1
SQL2
SQL1
SQL2
user
process
user
process
SQL3
SQL3
Result1
Result3
Result1
Result3
Result1
Result3
SQL4
Result4
Request Queue
Response Queue 1
Response Queue 2
Shared Processes
Dedicated Processes
LISTENER

SQL> select sid,serial#,username,service_name from v$session; --每個Session有⼀一筆記錄
!
SID SERIAL# USERNAME SERVICE_NAME
---------- ---------- -------------- ------------------------------
1 36 SYSMAN orcl --透過listener建⽴立連線，其所要求的service name為orcl
2 1 SYS$BACKGROUND --Background process所建⽴立的連線
3 1 SYS$BACKGROUND
4 1 SYS$BACKGROUND
5 1 SYS$BACKGROUND
6 1 SYS$BACKGROUND
7 1 SYS$BACKGROUND
8 1 SYS$BACKGROUND
9 1 SYS$BACKGROUND
10 1 SYS$BACKGROUND
22 127 SYSMAN orcl
24 467 SYSMAN orcl
33 31 DBSNMP SYS$USERS
35 8 SYSMAN orcl
39 533 DBSNMP SYS$USERS --使⽤用IPC所建⽴立的連線
42 683 HR orcl
43 658 SYSMAN orcl
44 274 DBSNMP SYS$USERS
45 98 SYS$BACKGROUND

Background Process
[oracle@oraDB ~]$ ps aux| grep ora_ | grep _orcl
oracle 22569 0.0 0.8 750600 18080 ? Ss 09:56 0:00 ora_w000_orcl
oracle 23513 0.4 1.5 751112 31000 ? Ds 10:07 0:00 ora_m000_orcl
oracle 29276 0.0 0.9 752896 20084 ? Ss Jan08 0:24 ora_pmon_orcl
oracle 29280 0.0 0.8 750604 16464 ? Ss Jan08 1:49 ora_psp0_orcl
oracle 29284 9.7 0.7 750604 16068 ? Ss Jan08 5:02 ora_vktm_orcl
oracle 29290 0.0 0.7 750604 16336 ? Ss Jan08 0:10 ora_gen0_orcl
oracle 29294 0.0 0.7 750604 16060 ? Ss Jan08 0:13 ora_diag_orcl
oracle 29298 0.0 2.0 751116 41756 ? Ss Jan08 0:10 ora_dbrm_orcl
oracle 29302 0.0 1.0 752140 20768 ? Ss Jan08 1:01 ora_dia0_orcl
oracle 29306 0.0 2.0 750604 42072 ? Ss Jan08 0:09 ora_mman_orcl
oracle 29310 0.0 4.8 758152 100212 ? Ss Jan08 0:27 ora_dbw0_orcl
oracle 29314 0.0 1.3 766156 26808 ? Ss Jan08 0:33 ora_lgwr_orcl
oracle 29318 0.0 1.1 750604 24388 ? Ss Jan08 1:25 ora_ckpt_orcl
oracle 29322 0.0 8.4 754196 173024 ? Ss Jan08 0:18 ora_smon_orcl
oracle 29326 0.0 1.5 751116 31544 ? Ss Jan08 0:03 ora_reco_orcl
oracle 29330 0.0 6.1 756580 125636 ? Ss Jan08 0:48 ora_mmon_orcl
oracle 29334 0.0 1.7 752356 36488 ? Ss Jan08 0:59 ora_mmnl_orcl
oracle 29338 0.0 0.7 752636 16028 ? Ss Jan08 0:07 ora_d000_orcl
oracle 29342 0.0 0.7 751800 14868 ? Ss Jan08 0:06 ora_s000_orcl
oracle 29785 0.0 0.8 750604 17724 ? Ss Jan08 0:03 ora_qmnc_orcl
oracle 29889 0.0 7.0 756312 144344 ? Ss Jan08 0:32 ora_cjq0_orcl
oracle 29893 0.0 1.9 752268 40884 ? Ss Jan08 0:03 ora_q000_orcl
oracle 29897 0.0 3.2 756140 65900 ? Ss Jan08 0:03 ora_q001_orcl
oracle 30496 0.0 1.2 751116 25208 ? Ss Jan08 0:09 ora_smco_orcl

Server Process
[oracle@oraDB ~]$ ps aux| grep oracleorcl
oracle 24862 0.0 1.4 754428 28856 ? Ss 10:22 0:01 oracleorcl (LOCAL=NO)
oracle 25022 3.7 1.0 758580 22540 ? Ss 10:24 1:36 oracleorcl (DESCRIPTION=(LOCAL=oracle 25243 0.1 6.1 768008 126452 ? Ss 10:27 0:04 oracleorcl (LOCAL=NO)
oracle 27580 74.9 2.2 774840 47180 ? Rs 10:51 12:50 oracleorcl (DESCRIPTION=(LOCAL=oracle 27681 0.0 1.0 766648 22544 ? Ss 10:51 0:00 oracleorcl (DESCRIPTION=(LOCAL=oracle 27714 0.0 1.0 766648 22052 ? Ss 10:51 0:00 oracleorcl (DESCRIPTION=(LOCAL=oracle 27715 0.0 1.0 766648 22044 ? Ss 10:51 0:00 oracleorcl (DESCRIPTION=(LOCAL=oracle 27725 0.0 1.0 766648 22060 ? Ss 10:51 0:00 oracleorcl (DESCRIPTION=(LOCAL=oracle 27735 0.0 1.0 766648 22232 ? Ss 10:51 0:00 oracleorcl (DESCRIPTION=(LOCAL=oracle 27745 0.0 1.0 766648 22256 ? Ss 10:51 0:00 oracleorcl (DESCRIPTION=(LOCAL=

[oracle@oracleDB ~]$ ipcs -m
!
------ Shared Memory Segments --------
key shmid owner perms bytes nattch status
0x00000000 65536 oracle 600 393216 2 dest
0x00000000 98305 oracle 600 393216 2 dest
0x00000000 131074 oracle 600 393216 2 dest
0x00000000 163843 oracle 600 393216 2 dest
0x00000000 196612 oracle 600 393216 2 dest
0x00000000 229381 oracle 600 393216 2 dest
0x00000000 262150 oracle 600 393216 2 dest
0x00000000 294919 oracle 600 393216 2 dest
0x00000000 327688 oracle 600 393216 2 dest
0x00000000 360457 oracle 600 393216 2 dest
0x00000000 58851338 oracle 660 4096 0
0x00000000 58884107 oracle 660 4096 0
0xfa55c7d8 720908 oracle 660 4096 0
0x00000000 1179661 oracle 600 393216 2 dest
0x00000000 109543438 oracle 777 138880 2 dest
0x42e38fd0 58916879 oracle 660 4096 0
0x00000000 109576208 oracle 777 138880 2 dest
0x00000000 57049105 oracle 777 138880 2 dest

SQL Execution Steps
Server Process
User Process Oracle Server
Parse
Execute
Fetch
(Select only)
$ sqlplus hr/hr@orcl
SQL> select last_name,salary
SQL
from employees
where employee_id=100;
Shared
Pool
Buffer
Cache
Log
Buffer
DML only
Datafile
LAST_NAME
SALARY
------------------------- ----------
King 24000
Result
Control
file
Log
File

Shared Pool
Library Cache
SQL Text/Parsed Code/Execution Plan
Data Dictionary Cache
Result Cache
SHARED_POOL_SIZE

Hard/Soft Parse
Execution Plan
Query Transformer
Estimator
Plan Generator
Row Source Generator
Execution Plan
Data
Dictionary
Parser
Optimizer
optimizer
statistics
Hash(SQL)
Execution Plan
Execution Plan
Execution Plan
Execution Plan
Execution Plan
Soft Parse Hard Parse
Execution Plan
Shared Pool
(Library Cache)
Syntax analysis
Semantic analysis
Server Process

Buffer Cache
Data Block Copy From DataFiles
Least Recently Used(LRU)
DBWR write Dirty Buffer to Datafile
DB_CACHE_SIZE Free/Unused
Clean
Dirty
DBWR write back
to datafile
Server process
read from datafile
Server process
Modify block content

Datafile
PGA
Select
Log Buffer
DBWR LGWR
Control
file
Logfile
group
1
Logfile
group
2
Server
Process
Execution
Plan
SMON PMON CKPT RECO
1 A A1
10 J J
10
17 Q Q17
2 B B2
18 R R18
19 S S1
9
3 C C3
7 G G7
11 K K
11
4 D D4
12 L L
12
21 U U
21
6 F F6
13 M M13
22 V V
22
8 H H8
15 O O15
24 X X
24
5 E E5
14 N N
14
23 W W23
9 I I9
16 P P
16
20 T T
20
A B C
1 A A1
2 B B2
3 C C3
4 D D4
5 E F5
6 F E6
7 G G7
8 H H8
9 I I9
10 J J10
11 K K11
12 L L12
13 M M13
14 N N14
15 O O15
16 P P16
17 Q Q17
18 R R18
19 S S19
20 T T20
21 U U21
22 V V22
23 W W23
24 X X24
User
Process
SELECT c FROM t1 WHERE a=19; 1.Parse
S19
3.Fetch
Shared
Pool Buffer Cache
2 B B2
18 R R18
19 S S1
9
2.Execute

Log Buffer
Redo Entry from Server Process’s PGA
DML/DDL
Circular buffer
LOG_BUFFER_SIZE

2.4
Copy Redo Entries to Log Buffer
Datafile
PGA
DML
Log Buffer
DBWR LGWR
Control
file
Logfile
group
1
Logfile
group
2
Server
Process
Execution
Plan
SMON PMON CKPT RECO
1 A A1
10 J J
10
17 Q Q17
2 B B2
18 R R18
19 S S1
9
3 C C3
7 G G7
11 K K
11
4 D D4
12 L L
12
21 U U
21
6 F F6
13 M M13
22 V V
22
8 H H8
15 O O15
24 X X
24
5 E E5
14 N N
14
23 W W23
9 I I9
16 P P
16
20 T T
20
A B C
1 A A1
2 B B2
3 C C3
4 D D4
5 E F5
6 F E6
7 G G7
8 H H8
9 I I9
10 J J10
11 K K11
12 L L12
13 M M13
14 N N14
15 O O15
16 P P16
17 Q Q17
18 R R18
19 S S19
20 T T20
21 U U21
22 V V22
23 W W23
24 X X24
User
Process
1.Parse
Shared
Pool Buffer Cache
2 B B2
18 R R18
19 S S9
1
UPDATE t1
SET c=‘S91’
WHERE a=19;
2.3
Generated
Redo Entries
undo S19
data S91
2.Execute
2.1
Get Data Blocks
1 row updated
2.2
Lock Row
undo S19
data S91
2.6
Change Date Block
2.5
S19
Copy before image
to Undo Block

Datafile
PGA
COMMIT
Log Buffer
DBWR LGWR
2.3
Write Redo Entries to Log File
Control
file
Logfile
group
1
Logfile
group
2
Server
Process
Execution
Plan
SMON PMON CKPT RECO
1 A A1
10 J J
10
17 Q Q17
2 B B2
18 R R18
19 S S1
9
3 C C3
7 G G7
11 K K
11
4 D D4
12 L L
12
21 U U
21
6 F F6
13 M M13
22 V V
22
8 H H8
15 O O15
24 X X
24
5 E E5
14 N N
14
23 W W23
9 I I9
16 P P
16
20 T T
20
A B C
1 A A1
2 B B2
3 C C3
4 D D4
5 E F5
6 F E6
7 G G7
8 H H8
9 I I9
10 J J10
11 K K11
12 L L12
13 M M13
14 N N14
15 O O15
16 P P16
17 Q Q17
18 R R18
19 S S91
20 T T20
21 U U21
22 V V22
23 W W23
24 X X24
User
Process
1.Parse
Shared
Pool Buffer Cache
2 B B2
18 R R18
19 S S9
1
S19
COMMIT;
commit
2.Execute
COMMITTED
undo S19
data S91
commit
2.1
Generated
Redo Entries
2.2
Copy Redo Entries to Log Buffer
undo S19
data S91
commit
2.4
Release Lock

DBWR&COMMIT
Datafile
PGA
Log Buffer
DBWR LGWR
Control
file
Logfile
group
1
Logfile
group
2
Server
Process
Execution
Plan
User
Process Shared
SMON PMON CKPT RECO
1 A A1
10 J J
10
17 Q Q17
2 B B2
18 R R18
19 S S9
1
3 C C3
7 G G7
11 K K
11
4 D D4
12 L L
12
21 U U
21
6 F F6
13 M M13
22 V V
22
8 H H8
15 O O15
24 X X
24
5 E E5
14 N N
14
23 W W23
9 I I9
16 P P
16
20 T T
20
A B C
1 A A1
2 B B2
3 C C3
4 D D4
5 E F5
6 F E6
7 G G7
8 H H8
9 I I9
10 J J10
11 K K11
12 L L12
13 M M13
14 N N14
15 O O15
16 P P16
17 Q Q17
18 R R18
19 S S91
20 T T20
21 U U21
22 V V22
23 W W23
24 X X24
Pool Buffer Cache
S19
undo S19
data S91
undo S19
data S91
2 B B2
18 R R18
19 S S9
1
S19

INSTANCE
Pool
SMON PMON DBWR LGWR CKPT RECO ARCH
Log Buffer
Group1
Datafiles
Group2
Controlfile
LogFiles
Archived
logfile
Program
Global
Area
ParameterFile
Password File
Alert Logfile
Trace File
DATABASE
User
Process
Server
Process

SCN是⼀一個數字,最快速度在⼀一秒內可以增加16384次(每次加1),Oracle Server使⽤用6 bytes儲存此值,並保證在522年不會⽤用盡。
SCN與時間有3秒差距
SQL> select timestamp_to_scn(to_date('2013-04-20:15:37:00','YYYY-MM-DD:HH24:MI:SS')) from dual;
!
TIMESTAMP_TO_SCN(TO_DATE('2013-04-20:15:37:00','YYYY-MM-DD:HH24:MI:SS'))
------------------------------------------------------------------------
1122536
!
!
------------------------------------------------------------------------
1122536
!
!
------------------------------------------------------------------------
1122536
!
!
------------------------------------------------------------------------
1122537
scn換算為timestamp時,有3秒鐘的誤差
!
SQL> select scn_to_timestamp(1122536) from dual;
!
SCN_TO_TIMESTAMP(1122536)
---------------------------------------------------------------------------
20-4⽉月 -13 03.37.00.000000000 下午
!
SQL> select scn_to_timestamp(1122537) from dual;
!
SCN_TO_TIMESTAMP(1122537)
---------------------------------------------------------------------------
20-4⽉月 -13 03.37.03.000000000 下午

Log Buffer
Con
trol
file
Logfil
e
group
1
Logfil
e
group
2
Shared Pool Buffer Cache
MMON
Data Dictionary
Automatic
Workload
Repository
X$
V$XXX
DBA_XXX
DBA_HIST_XXX

Data Dictionary View
DBA_TABLES
資料庫裡所有的表格。︒
ALL_TABLES
查詢此View的Session User所有可以使⽤用的表格。︒
包含⾃自⼰己擁有與他⼈人擁有但授權此Session User可
以使⽤用的表格。︒
USER_TABLES
查詢此View的Session User所擁有的表格。︒

!
SQL> desc dictionary
Name Null? Type
---------------------------- -------- ----------------------------
TABLE_NAME VARCHAR2(30)
COMMEN VARCHAR2(4000)
!
SQL> select substr(table_name,1,4),count(*)
2> from dictionary
3> where substr(table_name,1,4) in ('DBA_','ALL_','USER')
4> group by substr(table_name,1,4);
!
SUBSTR(T COUNT(*)
----------------- --------
ALL_ 355
USER 375
DBA 705
!
!

SQL> show user
USER is "SYSMAN"
SQL> select count(*) from user_tables;
!
COUNT(*)
----------
728
!
SQL> select count(*) from all_tables;
!
COUNT(*)
----------
832
!
SQL> select count(*) from dba_tables;
!
COUNT(*)
----------
2783
SQL> show user
USER is "HR"
SQL> select count(*) from user_tables;
!
COUNT(*)
----------
7
!
SQL> select count(*) from all_tables;
!
COUNT(*)
----------
106
!
SQL> select count(*) from dba_tables;
select count(*) from dba_tables
*
ERROR at line 1:
ORA-00942: table or view does not exist

Dynamic
Performance View
資料來源
INSTANCE(⼤大多數)/Control File(少數)/Data Dictionary(極少數)
Dynamic
內容持續變動，無法保證⼀一致性讀取。︒
Performance
其中資訊主要⽤用來進⾏行INSTANCE的效能調校。︒
Base Table
X$
V_$
Dynamic Performance View
V$

SQL> select count(*) from v$sql;
!
COUNT(*)
-----------------
847
SQL> desc v$fixed_table
Name Null? Type
------------------------------- -------- ------------
NAME VARCHAR2(30)
OBJECT_ID NUMBER
TYPE VARCHAR2(5)
TABLE_NUM NUMBER
!
SQL> startup force
ORACLE instance started.
!
Total System Global Area 418484224 bytes
Fixed Size 1336932 bytes
Variable Size 318769564 bytes
Database Buffers 92274688 bytes
Redo Buffers 6103040 bytes
Database mounted.
Database opened.
!
SQL> select count(*) from v$sql;
!
COUNT(*)
-----------------
285
--INSTANCE重新啟動,V$的內容將歸零重新累計

DATABASE
TABLESPACE
SEGMENT
EXTENT
LOGFILE
CONTROLFILE
DATAFILE
BLOCK OS BLOCK

SQL> select sum(bytes) from dba_data_files
2> where tablespace_name='EXAMPLE';
!
SUM(BYTES)
-------------------
362414080
!
SQL> select sum(bytes) from dba_segments
!
SUM(BYTES)
-------------------
324141056
!
SQL> select sum(bytes) from dba_extents
SUM(DBA_DATA_FILES) != SUM(DBA_EXTENTS)
!
SUM(BYTES)
-------------------
324141056
WHY?

DBA_TABLESPACES
DBA_SEGMENTS
DBA_EXTENTS
DBA_DATA_FILES
DBA_FREE_SPACE
SUM(DBA_DATA_FILES) =
SUM(DBA_EXTENTS)+SUM(DBA_FREE_SPACE)

SQL> SELECT sum(bytes) FROM dba_data_files WHERE tablespace_name='EXAMPLE';
!
SUM(BYTES)
-------------------
!
SQL> SELECT sum(bytes) FROM dba_segments WHERE tablespace_name='EXAMPLE';
!
SUM(BYTES)
-------------------
!
SQL> SELECT sum(bytes) FROM dba_extents WHERE tablespace_name='EXAMPLE';
!
SUM(BYTES)
-------------------
SUM(DBA_DATA_FILES) !=
362414080
324141056
324141056
WHY?
SUM(DBA_EXTENTS) + SUM(DBA_FREE_SPACE)
!
SQL> SELECT sum(bytes) FROM dba_free_space WHERE tablespace_name='EXAMPLE';
!
SUM(BYTES)
-------------------
37224448 --(362414080-324141056-37224448)=1048576(File Header Bitmap)

Auto Extent Size
SQL> CREATE TABLESPACE demots1
2 DATAFILE '/u02/oradata/orcl/demots01.dbf' SIZE 3M
3 EXTENT MANAGEMENT LOCAL
4 AUTOALLOCATE
5 SEGMET SPACE MANAGEMENT AUTO;
Bitmap
1 1 0
1M 2M
8
k
8
k
8
k
8
k
8
k
8
k
8
k
8
k
extent
Extent size:
64K : 1-16
1M : 17-79
8M : 80-200
64M : 201- ...
64
K
64
K
64
K
64
K
64
K
64
K
64
K
64
K
64
K
64
K
64
K
64
K
64
K
64
K
64
K
64
K
64
K
64
K
64
K
64
K
64
K
64
K
64
K
64
K
64
K
64
K
64
K
64
K
64
K
64
K
64
K
64
K

Uniform extent size
4 UNIFORM SIZE 128K
5 SEGMENT SPACE MANAGEMENT AUTO;
1 1 0
Bitmap
1M 2M 8
k
8
k
8
k
8
k
8
k
8
k
8
k
8
k
8
k
8
k
8
k
8
k
8
k
8
k
8
k
8
k
extent
Extent size:128K
128
K
128
K
128
K
128
K
128
K
128
K
128
K
128
K
128
K
128
K
128
K
128
K
128
K
128
K
128
K
128
K

4 AUTOALLOCATE;
!
SQL> SELECT file_id,block_id,bytes,blocks
2 FROM dba_free_space
3 WHERE tablespace_name='DEMOTS';
!
FILE_ID BLOCK_ID
BYTES BLOCKS
--------------- ----------------- -------------- ---------------
7 128 9437184 1152
!
SQL> SELECT 10*1024*1024-9437184 FROM dual;
!
10*1024*1024-9437184
-----------------------------
1048576

4 UNIFORM SIZE 128K;
!
SQL> SELECT file_id,block_id,bytes,blocks
2 FROM dba_free_space
3 WHERE tablespace_name='DEMOTS2';
!
FILE_ID BLOCK_ID
BYTES BLOCKS
--------------- ----------------- -------------- ---------------
7 128 9437184 1152
!
SQL> SELECT 10*1024*1024-9437184 FROM dual;
!
10*1024*1024-9437184
-----------------------------
1048576

SQL> CREATE TABLE hr.t1
2> ( a NUMBER,
3> b VARCHAR2(100))
4> TABLESPACE demots1;
DDL=DML on Data Dictionary
1 11 1 1 1 1 1111111101110010100 x$ktfbue 11 1 1 0 1101111000000000000
obj$
123 T1
seg$
123 123 T1
tab$
col$
123 T1
123 T1 A N
123 T1 B V
SQL> INSERT INTO hr.t1
HWM
2> VALUES(1,’A’); 1 A
SQL> INSERT INTO hr.t1
2> VALUES(2,’B’);
2 B
3 C
SYSTEM DEMOTS1

Delete
HR.T1’s Definition HR.T1’s Data
1 11 1 1 1 1 1111111101110010100 x$ktfbue 11 1 1 1 1101111000000000000
obj$
123 T1
seg$
123 123 T1
tab$
col$
123 T1
123 T1 A Number
123 T1 B Varchar2
HWM
1 A
2 B
3 C
SQL> DELETE hr.t1
2> WHERE a=1;
SQL> DELETE hr.t1
2> WHERE b=’D’;
4 D
5 E
6 F
SYSTEM DEMOTS1

Truncate
HR.T1’s Definition HR.T1’s Data
1 11 1 1 1 1 1111111101110010100 x$ktfbue 11 1 1 0 1101111000000000000
obj$
123 T1
seg$
123 123 T1
tab$
col$
123 T1
123 T1 A Number
123 T1 B Varchar2
HWM
1 A
2 B
3 C
SQL> truncate table
2> hr.t1;
4 D
5 E
6 F
SYSTEM DEMOTS1

Lock Type
DDL Lock
避免同時間多個Session異動相同表格的表
格定義。︒
DML Lock
避免同時間多個Session異動相同的資料列
避免在異動過程中，其他Session對同⼀一個

DDL Locks
Table Level Lock(TM)
eXclusive Lock
CREATE/ALTER/DROP TABLE/INDEX/CLUSTER/TABLESPACE
Share Lock
AUDIT/NOAUDIT/COMMENT
CREATE VIEW/PROCEDURE/FUNCTION/PACKAGE/PACKAGE BODY/
TRIGGER
CREATE SYNONYM
Breakable Parse Lock
SQL Statement與PL/SQL物件載入Shared Pool

DML Locks
Table Level Lock(TM)
Row eXclusive(RX)
Row Level Lock(TX)
eXclusive(X)

Get Lock
Automatic
DDL -> Table Level(TM):X/S
DML -> 1:TM:RX
2:TX:X
Manual
SQL> LOCK TABLE t1 IN {ROW SHARE|
ROW EXCLUSIVE|SHARE|SHARE ROW
EXCLUSIVE|EXCLUSIVE} MODE;

Lock Table
NULL Row Share Row eXclusive Share
Share
Row
eXclusive
eXclusive
NULL(1) ✔
✔
✔
✔
✔
✔
RS(2) ✔
✔
✔
✔
✔
RX(3) ✔
✔
✔
S(4) ✔
✔
✔
SRX(5) ✔
✔
X(6) ✔

Block Structure
Block Address/Segment Type
Transaction Slots
Table Directory
Row Directory
Block Header
Command Header
Block Overhead Variable Header
Row
Row
Row
Row
Row
Row Row
Row
Free Space
Row Data
Row Header Column Data
Row
Overhead
Lock
Byte
Column
Value
Column
Length
Chaining
info
Number of
Columns
5 10001 6 ORACLE 0 20 Administration Workshop 1
5 Bytes 6 Bytes 20 Bytes
4
Column
Value
Column
Value
Column
Value

Transaction
TRANSACTION的組成份⼦子:
多個DMLs指令
⼀一個DDL
⼀一個DCL

Begin/END of TX
Begin of TRANSACTION
上⼀一個TRANSACTION結束後，遇到第⼀一個的DML指令。︒
End of TRANSACTION
COMMIT
AUTO COMMIT
遇到DDL/DCL指令
正常結束SESSION
ROLLBACK
AUTO ROLLBACK
INSTANCE CRASH
SESSION不正常結束

Transaction ID
SQL> COMMIT; --結束⽬目前的交易
!
SQL> UPDATE TABLE t1 --開始另⼀一個交易.Transaction ID將先被指定.
2> SET salary=3000
3> WHERE empid=100;
!
SQL> SELECT xidusn,xidslot,xidsqn,ubafil,ubablk,ubasqn,status,ses_addr,xid
2> FROM v$transaction;
!
XIDUSN XIDSLOT XIDSQN UBAFIL UBABLK UBASQN STATUS SES_ADDR
XID
---------------- --------------- -------------- ------------- --------------- --------------- ------------ ------------------------- --------------------------
3 31 1253 3 1198
354 ACTIVE 000000007E454C58 03001F00E5040000
!
SQL> SELECT sid,type,id1,id2,lmode,request
2> FROM v$lock
3> WHERE type IN ('TM','TX');
!
SID TY ID1 ID2 LMODE REQUEST
----------- ----- ---------- ---------- ------------- ---------------
125 TM 77329 0
3 0
125 TX 196639 1253 6 0
XIDUSN=trunc(196639/power(2,16))
XIDSLOT=bitand(196639,to_number('ffff','xxxx'))
XIDSQN=1253

Transaction&Block
Transaction slots
100 Frank 10-May-12 2000
Undo
Segment #1
Undo
Segment #2
Undo
Segment #3
Transaction Table
Trans
TBL
Index State Wrap DBA
1 9 1100
2 10 989
..... ...... ......
31 9 1252
SQL> COMMIT;
1 2 3 4 5
Row Directory

Transaction&Block
Transaction slots
3.31.1253
100 Frank 10-May-12 3000
Undo
Segment #1
Undo
Segment #2
Undo
Segment #3
Transaction Table
Trans
TBL
1 9 1100
2 10 989
...... ...... ......
31 10 1253 3.1198
SQL> COMMIT;
SQL> UPDATE TABLE t1
2> SET salary=3000
3> WHERE empid=100;
1 2 3 4 5
2
2000
Transaction ID
Row Directory

CR Block
--另⼀一個SESSION
SQL> SELECT ＊FROM t1 WHERE empid=100;
!
EMPID EMP_NAM HIRE_DATE SALARY
---------- ------------- --------------- ----------
100 Frank 10-May-12 2000 Undo
Segment #1
Undo
Segment #2
Undo
Segment #3
Transaction Table
Trans
TBL
1 9 1100
2 10 989
..... ...... ......
31 10 1253 3.1198
2000
Transaction slots
3.31.1253
1 2 3 4 5
step 1 step 2
step 7
100 Frank 10-May-12 3000
2
step 3
Transaction slots
3.31.1253
1 2 3 4 5
100 Frank 10-May-12 2000
2
XCUR Block Consistent Read Block
step 5
step 6
step 4

Undo Management
Automatic Undo Management(AUM)
UNDO_MANAGEMENT=AUTO
UNDO_TABLESPACE=undotbs1
UNDO_RETENTION=900

SQL> SELECT tablespace_name,contents FROM dba_tablespaces;
!
TABLESPACE_NAME CONTENTS
------------------------------- -------------------
SYSTEM PERMANENT
SYSAUX PERMANENT
UNDOTBS1 UNDO
TEMP TEMPORARY
USERS PERMANENT
EXAMPLE PERMANENT
!
SQL> CREATE UNDO TABLESPACE undotbs2
2> DATAFILE ‘/u02/oradata/orcl/undotbs2.dbf’ SIZE 1000M
3> AUTOEXTEND ON NEXT 100M MAXSIZE 5000M;
!
SQL> SELECT tablespace_name,contents FROM dba_tablespaces;
!
TABLESPACE_NAME CONTENTS
------------------------------- -------------------
SYSTEM PERMANENT
SYSAUX PERMANENT
UNDOTBS1 UNDO
TEMP TEMPORARY
USERS PERMANENT
EXAMPLE PERMANENT
UNDOTBS2 UNDO
!
SQL> ALTER SYSTEM SET undo_tablespace=UNDOTBS2;

Oracle Database Management Basic 1

Recomendados

Recomendados

Más contenido relacionado

La actualidad más candente

La actualidad más candente (20)

Destacado

Destacado (20)

Similar a Oracle Database Management Basic 1

Similar a Oracle Database Management Basic 1 (20)

Último

Último (20)

Oracle Database Management Basic 1