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TRUNGTMINTONCTYINLC2

TP.HCM 02/ 2004


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Ti liu tham kho- H qun tr c s d liu Oracle

Trung tm in Ton - Cng Ty in Lc 2 Trang1

MC LC

CHNG 1. CC IM MI TRONG ORACLE 9I ........................................... 9

CHNG 2. CC THNH PHN KIN TRC ................................................ 14

2.1. KIN TRC ORACLE SERVER........................................................................................142.1.1. Oracle Instance...............................................................................................................142.1.2. Oracle database ..............................................................................................................192.1.3. Qun tr c s d liu Oracle ...........................................................................................232.1.4. Thit lp cc tham s khi to nh hng ti kch c b nh SGA......................................23

2.2. KT NI TI ORACLE SERVER .....................................................................................242.2.1. M hnh kt ni ...............................................................................................................242.2.2. Mt s khi nim c bn lin quan n kt ni .................................................................252.2.3. Kt ni ti database ........................................................................................................25

CHNG 3. CC CNG C QUN TR ORACLE........................................... 273.1. CC CNG C QUN TR C S D LIU ORACLE ......................................................273.2. SERVER MANAGER LINE MODE ....................................................................................27

3.2.1. Truy nhp Server Manager Line Mode ..............................................................................273.2.2. Phn nhm cc lnh trong Server manager.......................................................................283.2.3. Din gii cc lnh trong Server manager ..........................................................................28

3.3. ORACLE ENTERPRISE MANAGER..................................................................................293.3.1. Kin trc OME.................................................................................................................293.3.2. Cc dch v chung...........................................................................................................303.3.3. Oracle Configuration Assistant .........................................................................................303.3.4. Oracle Enterprise Manager Console ..................................................................................30

3.4. CC CNG C QUN TR KHC ....................................................................................31

CHNG 4. TO DATABASE........................................................................ 324.1. CC BC TO DATABASE...........................................................................................324.2. CHUN B MI TRNG ..............................................................................................32

4.2.1. Chun b h iu hnh ....................................................................................................324.2.2. Ln k hoch b tr cc file thng tin................................................................................324.2.3. Optimal Flexible Architecture OFA .................................................................................334.2.4. Cu trc th mc phn mm Oracle .................................................................................344.2.5. Bin mi trng ..............................................................................................................34

4.3. CHUN B CC THAM S TRONG PARAMETER FILE ....................................................354.4. CHUN B INSTANCE PHC V QUN TR...................................................................36

4.4.1. To mt instance ............................................................................................................36

4.4.2. Khi ng instance..........................................................................................................374.4.3. Dng instance.................................................................................................................374.4.4. Hu instance...................................................................................................................38

4.5. TO DATABASE.............................................................................................................384.5.1. Khi ng Instance .........................................................................................................384.5.2. Lnh to database ..........................................................................................................384.5.3. Oracle Database Assistant ...............................................................................................394.5.4. File script v d to mt database.....................................................................................404.5.5. Li xy ra khi to database ..............................................................................................414.5.6. Kt qu sau khi to database...........................................................................................41

4.6. TO DATA DICTIONARY CHO DATABASE .....................................................................42

CHNG 5. QUN TR ORACLE DATABASE ................................................ 435.1. PHN LOI USERS........................................................................................................43


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5.1.1. Database Administrators..................................................................................................435.1.2. Security Officers..............................................................................................................435.1.3. Application Developers ....................................................................................................445.1.4. Database Users...............................................................................................................445.1.5. Network Administrators ...................................................................................................44

5.2. PHNG THC XC NHN C QUYN TRUY NHP...................................................445.2.1. Phng thc xc nhn quyn ..........................................................................................44

5.2.2. Xc nhn quyn bi h iu hnh ....................................................................................455.2.3. Xc nhn quyn bng file mt khu .................................................................................465.2.4. Thay i mt khu internal ..............................................................................................46

5.3. TO PARAMETER FILE..................................................................................................475.3.1. S dng cc tham s.......................................................................................................475.3.2. Mt s quy tc i vi cc tham s ..................................................................................485.3.3........................................................................................................................................485.3.4. Cc tham s c bn.........................................................................................................48

5.4. START V SHUT DOWN DATABASE ..............................................................................495.4.1. Cc bc Start v Shut down database ............................................................................495.4.2. Start database ................................................................................................................515.4.3. Thay i tnh sn dng ca database hin thi .................................................................515.4.4. Shut down database........................................................................................................525.4.5. Thay i trng thi ca database .....................................................................................535.4.6. Tm treo v phc hi Database .......................................................................................545.4.7. t ch hot ng tnh cho database ..........................................................................55

5.5. T TRNG THI TNH CHO DATABASE ......................................................................555.5.1. a Database vo trng thi tnh.....................................................................................555.5.2. Phc hi h thng tr li hot ng nh bnh thng........................................................565.5.3. Xem trng thi ca database ...........................................................................................56

5.6. LY CC THNG TIN V H THNG .............................................................................565.6.1. Mt s views cn quan tm .............................................................................................575.6.2. Hin th gi tr ca cc thng s h thng .........................................................................57

5.6.3. Tham s h thng ng (c th thay i).........................................................................58

5.6.4. Qun l session...............................................................................................................585.6.5. Trace file v ALERT file....................................................................................................59

CHNG 6. DATA DICTIONARY, VIEWS V PACKAGES............................. 606.1. DATA DICTIONARY V VIEWS .....................................................................................60

6.1.1. Data Dictionary ...............................................................................................................606.1.2. Data Dictionary views......................................................................................................616.1.3. Sripts qun tr .................................................................................................................63

6.2. STORED PROCEDURES V CC PACKAGES CHUN ......................................................646.2.1. Gii thiu chung..............................................................................................................646.2.2. Stored procedures...........................................................................................................64

6.2.3. Packages chun ..............................................................................................................656.2.4. Gii thiu mt s packages chun do Oracle cung cp.......................................................656.2.5. Package DBMS_METADATA ..............................................................................................676.2.6. Package dbms_redefinition ..............................................................................................68

6.3. THNG TIN V CC STORED PROCEDURES .................................................................68

CHNG 7. QUN TR CONTROL FILES ..................................................... 717.1. CONTROL FILES............................................................................................................71

7.1.1. Gii thiu control file .......................................................................................................717.1.2. Cch thc t tn control file ...........................................................................................717.1.3. Kt hp nhiu control files ...............................................................................................717.1.4. Ni dung ca control file..................................................................................................727.1.5. Cc tham s nh hng ti kch thc ca control file.......................................................73

7.2. QUN TR CONTROL FILE.............................................................................................737.2.1. To mi control file .........................................................................................................73


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7.2.2. To mi control file cho mt database c sn...............................................................757.2.3. Mt s li i vi cc Control Files....................................................................................757.2.4. Hu b Control Files ........................................................................................................76

7.3. THNG TIN TRNG THI CA CONTROL FILES ...........................................................77

CHNG 8. QUN L REDO LOG FILES ...................................................... 78

8.1. S DNG CC REDO LOG FILES ...................................................................................78

8.1.1. Redo log file ...................................................................................................................788.1.2. Online Redo Log Groups ..................................................................................................788.1.3. Online Redo Log Members ...............................................................................................788.1.4. Ni dung ca Online Redo Log Files (Members) ................................................................798.1.5. Active v Inactive Online Redo Log Files ...........................................................................798.1.6. Thit lp cc Redo Log Files khi to................................................................................79

8.2. LGWR, LOG SWITCHES V CHECKPOINTS ...................................................................808.2.1. Redo Log Buffer v Background process LGWR.................................................................808.2.2. Log Switches ..................................................................................................................808.2.3. Checkpoints ....................................................................................................................81

8.3. LN K HOCH S DNG REDO LOG FILES .................................................................81

8.3.1. Xc nh s lng Online redo log files .............................................................................818.3.2. Ni t cc Online Redo Log Files ....................................................................................818.3.3. Xc nh kch thc cho cc Online Redo Log Files............................................................828.3.4. Lu tr cc redo log files.................................................................................................82

8.4. IU KHIN LU TR SAU I VI PRIMARY/STANDBY ..........................................838.4.1. Thit lp tham s ARCHIVE_LAG_TARGET........................................................................838.4.2. Cc yu t nh hng ti tham s ARCHIVE_LAG_TARGET ...............................................84

8.5. XC NH CH LU TR ........................................................................................848.5.1. S dng lnh Server Manager ..........................................................................................848.5.2. S dng thng tin trong data dictionary ...........................................................................85

8.6. IU KHIN CC LOG SWITCHS V CHECKPOINTS ....................................................868.6.1. Thc hin log switches ....................................................................................................86

8.6.2. Thc hin checkpoint ......................................................................................................868.6.3. iu chnh cc ngt qung checkpoints ............................................................................86

8.7. QUN TR CC REDO LOG FILES..................................................................................878.7.1. B sung cc online redo log groups ..................................................................................878.7.2. B sung cc online redo log members ..............................................................................888.7.3. nh li ch cho cc redo log file......................................................................................888.7.4. Ngng s dng cc Online redo log groups ......................................................................898.7.5. Ngng s dng cc Online redo log members...................................................................908.7.6. Xo rng Online redo log file............................................................................................91

CHNG 9. QUN TR TABLESPACES V DATA FILES ............................... 92

9.1. CU TRC CA DATABASE ...........................................................................................92

9.1.1. Quan h gia database vi cc tablespaces v data files ...................................................929.1.2. Quan h gia segment vi cc extent v cc blocks ..........................................................93

9.2. PHN LOI CC TABLESPACES ...................................................................................949.2.1. Tablespace SYSTEM v non-SYSTEM................................................................................949.2.2. Tablespaces read-only / read-write ..................................................................................959.2.3. Temporary tablespace / permanent tablespace .................................................................95

9.3. QUN L KHNG GIAN TRONG TABLESPACES.............................................................969.3.1. Dictionary-Managed Tablespaces .....................................................................................969.3.2. Locally-Managed Tablespaces ..........................................................................................96

9.4. THIT LP TRNG THI CHO TABLESPACES................................................................97

9.5. TRAO I CC TABLESPACES GIA DATABASES ........................................................979.5.1. Mt s hn ch trong vic trao i cc tablespace: ...........................................................989.5.2. Cc bc thc hin chuyn i mt tablespace gia cc database .....................................98

9.6. TO TABLESPACE .........................................................................................................99


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9.6.1. Lnh to tablespace ........................................................................................................999.6.2. Ch qun l cc tablespaces .....................................................................................1019.6.3. To temporary tablespace .............................................................................................1019.6.4. Cc tham s lu tr ......................................................................................................101

9.7. CC THAY I I VI TABLESPACE........................................................................1029.7.1. Chuyn i mt tablespace thnh mt temporary tablespace...........................................1029.7.2. Thm mi cc tablespace ..............................................................................................102

9.7.3. M rng data files .........................................................................................................1039.7.4. Thay i kch thc data file..........................................................................................1039.7.5. Chuyn i ch ONLINE v OFFLINE .........................................................................1049.7.6. Di chuyn cc data file ..................................................................................................1059.7.7. Tablespace ch c........................................................................................................1069.7.8. Hu tablespace .............................................................................................................106

9.8. THNG TIN V CC TABLESPACES.............................................................................1079.8.1. Xem thng tin tablespace ..............................................................................................1089.8.2. Xem thng tin data files.................................................................................................108

CHNG 10. CU TRC LU TR............................................................. 110

10.1. CC LOI SEGMENTS ...............................................................................................110

10.1.1. Table..........................................................................................................................11010.1.2. Table partition.............................................................................................................11010.1.3. Cluster........................................................................................................................11010.1.4. Index..........................................................................................................................11010.1.5. Index-Organized Table ................................................................................................11110.1.6. Index Partition ............................................................................................................11110.1.7. Rollback Segment........................................................................................................11110.1.8. Temporary Segment....................................................................................................11110.1.9. LOB Segment..............................................................................................................11110.1.10. LOB Index.................................................................................................................11210.1.11. Nested Table.............................................................................................................11210.1.12. Bootstrap Segment ....................................................................................................112

10.2. QUN L EXTENTS....................................................................................................11210.2.1. Cp pht v thu hi cc extents ...................................................................................11210.2.2. S dng v gii phng cc extent.................................................................................11310.2.3. Kt hp cc vng khng gian trng ..............................................................................113

10.3. BLOCK D LIU ........................................................................................................11510.3.1. Cu trc ca block d liu............................................................................................11510.3.2. Cc tham s s dng khng gian trong block................................................................11610.3.3. S dng khng gian trong block...................................................................................11710.3.4. Phn loi mc phn on i vi tng loi segment .................................................117

10.4. THNG TIN V CU TRC LU TR .........................................................................11810.4.1. Cc view lu tr thng tin............................................................................................118

10.4.2. Xem thng tin v cc segments....................................................................................119

10.4.3. Thng tin v cc extents..............................................................................................12010.4.4. Thng tin v cc vng trng ........................................................................................121

CHNG 11. QUN L ROLLBACK SEGMENTS ......................................... 12211.1. GII THIU ROLLBACK SEGMENTS .........................................................................122

11.1.1. Khi nim ...................................................................................................................12211.1.2. Mc ch s dng segment ..........................................................................................12211.1.3. Phn loi rollback segment ..........................................................................................123

11.2. S DNG ROLLBACK SEGMENT................................................................................12411.2.1. S dng rollback segment trong cc transaction............................................................12411.2.2. Tng trng i vi cc rollback segments ...................................................................125

11.2.3. Ti u cc rollback segments .......................................................................................12611.3. QUN L ROLLBACK SEGMENTS ..............................................................................126

11.3.1. S dng rollback segment............................................................................................126


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11.3.2. To rollback segment ..................................................................................................12711.3.3. Thay i trng thi ca Rollback segments ...................................................................12811.3.4. Instance s dng rollback segment ..............................................................................12911.3.5. iu chnh kh nng lu tr ca rollback segment ........................................................12911.3.6. Gim bt rng ca rollback segment........................................................................12911.3.7. Hy b rollback segment .............................................................................................13011.3.8. Qun l undo t ng .................................................................................................130

11.4. THNG TIN V CC ROLLBACK SEGMENT................................................................13111.4.1. Xem thng tin chung v cc rollback segment...............................................................13111.4.2. Xem thng tin thng k v rollback segment.................................................................13211.4.3. Thng tin v rollback segment ang active ...................................................................133

11.5. CC VN LIN QUAN TI ROLLBACK SEGMENT.................................................13411.5.1. Thiu khng gian cho cc transactions .........................................................................13411.5.2. Li c d liu khng ng nht ..................................................................................13411.5.3. Chn session...............................................................................................................135

CHNG 12. QUN L TEMPORARY SEGMENTS......................................13712.1. TEMPORARY SEGMENTS...........................................................................................137

12.1.1. Phn loi temporary segments .....................................................................................138

12.1.2. S dng cc Sort Segments .........................................................................................13912.1.3. Sort Extent Pool ..........................................................................................................139

12.2. CP PHT KHNG GIAN CHO TEMPORARY SEGMENT .............................................13912.3. THNG TIN V CC TEMPORARY SEGMENT ............................................................140

CHNG 13. CLUSTERS V INDEX-ORGANIZED TABLES ........................ 14213.1. TNG QUAN V CLUSTERS V INDEX-ORGANIZED TABLES ....................................142

13.1.1. Cluster........................................................................................................................14313.1.2. Xem xt v chn la Cluster ........................................................................................14413.1.3. Cc kiu cluster...........................................................................................................14413.1.4. Chn la kiu cluster ...................................................................................................145

13.2. QUN L CLUSTER....................................................................................................14613.2.1. To cluster..................................................................................................................14613.2.2. To Hash Cluster.........................................................................................................14813.2.3. Xc nh gi tr SIZE cho cluster ...................................................................................14913.2.4. Cc tham s ch nh cho hash cluster ..........................................................................14913.2.5. Sa i cc Cluster......................................................................................................15013.2.6. Xo Cluster .................................................................................................................151

13.3. THNG TIN V CC CLUSTERS.................................................................................15313.3.1. Xc nh Cluster v cc ct kho Cluster .......................................................................15313.3.2. Ly thng tin ct kho ca cluster v cc ct trong bng...............................................15413.3.3. Ly thng tin cho hash cluster .....................................................................................154

13.4. INDEX-ORGANIZED TABLE.......................................................................................155

13.4.1. Tnh cht chung ..........................................................................................................15513.4.2. To mt index-organized table .....................................................................................15613.4.3. Hin tng ROW OVERFLOW (trn dng d liu) ..........................................................15813.4.4. Ly thng tin IOT (Index Orrganized Table).................................................................159

CHNG 14. QUN L CC TABLES.......................................................... 16014.1. TNG QUAN V TABLES............................................................................................160

14.1.1. Phn loi cc tables .....................................................................................................16014.1.2. Cu trc cc dng d liu (row data)............................................................................160

14.2. CC KIU D LIU TRONG TABLE............................................................................16114.2.1. Kiu d liu v hng .................................................................................................161

14.2.2. Tp hp (collection) ....................................................................................................16514.2.3. Kiu quan h (REF) .....................................................................................................16614.2.4. Kiu d liu TIMESTAMP..............................................................................................166


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14.3. QUN L CC TABLES...............................................................................................16614.3.1. To table ....................................................................................................................16614.3.2. Thit lp gi tr PCTFREE v PCTUSED..........................................................................16814.3.3. Migration (di tr) v Chaining cc dng d liu .............................................................16914.3.4. Sao chp mt tables ....................................................................................................16914.3.5. Qun tr columns trong table........................................................................................17014.3.6. Chuyn mt Table ti Segment hay Tablespace mi ......................................................172

14.3.7. nh ngha li mt table ang online ............................................................................17214.3.8. Bng ngoi External table .........................................................................................17414.4. CC RNG BUC (CONSTRAINTS) I VI TABLES ...............................................175

14.4.1. Rng buc i vi tables..............................................................................................17514.4.2. Null / Not Null .............................................................................................................17514.4.3. Unique........................................................................................................................17614.4.4. Primary Key ................................................................................................................17614.4.5. Foreign Key ( Referential Key)......................................................................................17614.4.6. Check .........................................................................................................................177

14.5. QUN L KHNG GIAN LU TR TRONG TABLE......................................................17714.5.1. Thay i thng tin lu tr v tham s s dng Block.....................................................17714.5.2. Cp pht cc extents bng tay (manually) ....................................................................178

14.5.3. High Water Mark .........................................................................................................17914.5.4. Thu hi khng gian khng s dng ..............................................................................18014.5.5. Truncate mt table......................................................................................................18114.5.6. Xo table ....................................................................................................................18114.5.7. Kim tra cu trc bng ................................................................................................18214.5.8. Pht hin cc rows b migration....................................................................................182

14.6. THNG TIN V TABLES.............................................................................................18314.6.1. Thng tin chung v cc tables......................................................................................18314.6.2. Thng tin v s dng block v thng tin chaining..........................................................184

CHNG 15. QUN L CC INDEXES ....................................................... 18515.1. PHN LOI INDEXES................................................................................................185

15.1.1. Index trn mt column v Index trn nhiu columns.....................................................18515.1.2. Unique index v Non-unique index ...............................................................................18515.1.3. Partitioned index v non-partitioned index ....................................................................185

15.2. T CHC INDEX .......................................................................................................18515.2.1. B-TREE index ..............................................................................................................18515.2.2. Reverse Key Index ......................................................................................................18715.2.3. Bitmap Index ..............................................................................................................18815.2.4. So snh gia B-TREE index v Bitmap index .................................................................189

15.3. QUN L INDEX........................................................................................................18915.3.1. To cc index..............................................................................................................18915.3.2. Mt s cch s dng index ..........................................................................................192

15.3.3. To Index kho ngc (reverse key index) ...................................................................193

15.3.4. To Bitmap index ........................................................................................................19315.3.5. Thay i tham s lu tr cho index ..............................................................................19415.3.6. Cp pht v thu hi khng gian s dng ca index .......................................................19415.3.7. Xy dng li (Rebuild) cc index ..................................................................................19515.3.8. Kim tra tnh hp l ca index......................................................................................19615.3.9. Xo cc index..............................................................................................................197

15.4. THNG TIN V CC INDEX.......................................................................................19715.4.1. Xem thng tin v cc index ..........................................................................................19715.4.2. Tm cc ct trong mt index ........................................................................................198

CHNG 16. NP V T CHC LU TR D LIU................................... 199

16.1. GII THIU CHUNG .................................................................................................19916.1.1. Tng quan vic np d liu..........................................................................................19916.1.2. Np d liu trc tip....................................................................................................200


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16.2. NP D LIU ............................................................................................................20016.2.1. Np d liu bng SQL* Loader .....................................................................................20016.2.2. Phng php np d liu.............................................................................................20216.2.3. So snh hai phng php np d liu...........................................................................20316.2.4. Np d liu ng thi (Parallel direct load) ...................................................................204

16.3. NP D LIU BNG SQL*LOADER ...........................................................................20616.3.1. S dng SLQ*LOADER.................................................................................................206

16.3.2. Parameter file (tp tham s) ........................................................................................20716.3.3. Control file (tp iu khin) .........................................................................................20816.3.4. Data file......................................................................................................................21016.3.5. Cc thnh phn ca log file..........................................................................................21016.3.6. Cc file u ra khc .....................................................................................................21016.3.7. Cc hng dn khi s dng load.................................................................................211

16.4. T CHC LI D LIU BNG CNG C EXPORT V IMPORT ..................................21216.4.1. Cng c dch chuyn d liu ........................................................................................21216.4.2. Cc ch Export .......................................................................................................21316.4.3. Export d liu trc tip v Export d liu thng thng.................................................214

16.5. CNG C EXPORT.....................................................................................................21516.5.1. S dng cng c Export .............................................................................................21516.5.2. Gii thiu mt s ch export ...................................................................................21716.5.3. Cc tablespaces trao i ..............................................................................................21916.5.4. Mt s thng bo khi export: Warning, Error, v Completion Messages ..........................219

16.6. CNG C IMPORT ....................................................................................................22016.6.1. S dng cng c Import ..............................................................................................22016.6.2. Chuyn i character set .............................................................................................224

CHNG 17. QUN L USER ....................................................................22517.1. USER TRONG DATABASE ..........................................................................................225

17.1.1. User v nhng thnh phn lin quan ............................................................................22517.1.2. Database schema........................................................................................................226

17.2. QUN L USER .........................................................................................................22617.2.1. Cc bc thc hin khi to mi user.............................................................................22617.2.2. To mi user vi c ch xc nhn bi database ............................................................22717.2.3. Thay i thuc tnh ca user ........................................................................................22817.2.4. Thay i hn mc (quota) s dng tablespace..............................................................22817.2.5. Hu User ....................................................................................................................229

17.3. THNG TIN V USER ................................................................................................229

CHNG 18. QUN L THNG TIN PROFILES ......................................... 23118.1. GII THIU PROFILE ...............................................................................................231

18.2. QUN L PROFILE ....................................................................................................232

18.2.1. To Profile ..................................................................................................................232

18.2.2. Thit lp cc gii hn v ti nguyn .............................................................................23318.2.3. Gn Profile cho User ....................................................................................................23318.2.4. t gii hn ti nguyn ...............................................................................................23418.2.5. Thay i thng tin trong profile....................................................................................23418.2.6. Hu profile ..................................................................................................................23518.2.7. Thng tin v cc gii hn ti nguyn ............................................................................235

18.3. QUN L MT KHU.................................................................................................23618.3.1. To profile qun l mt khu .......................................................................................23718.3.2. Cc tham s iu chnh mt khu.................................................................................23818.3.3. Mt s c im chnh trong qun l mt khu.............................................................23818.3.4. Hm cung cp mt khu cho ngi s dng .................................................................239

18.3.5. Thng tin v mt khu ................................................................................................239

CHNG 19. CC QUYN H THNG........................................................ 24119.1. PHN LOI QUYN...................................................................................................241


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19.1.1. Cc quyn h thng ....................................................................................................24119.1.2. Gn cc quyn h thng ..............................................................................................24119.1.3. Xc nhn user bng password file ...............................................................................24219.1.4. Thng tin v cc quyn ...............................................................................................243

19.2. QUN L QUYN.......................................................................................................24419.2.1. Thu hi cc quyn h thng.........................................................................................24419.2.2. Quyn trn cc i tng ............................................................................................245

19.2.3. Gn cc quyn trn i tng......................................................................................24619.2.4. Thng tin v cc quyn ...............................................................................................24619.2.5. Thu hi cc quyn trn i tng.................................................................................247

CHNG 20. QUN L CHC DANH (ROLE)............................................. 24920.1. CHC DANH (ROLE) TRONG DATABASE..................................................................249

20.1.1. Cc tnh cht ca chc danh ........................................................................................24920.1.2. Li ch ca vic s dng chc danh ..............................................................................249

20.2. QUN L CHC DANH ..............................................................................................25020.2.1. To v sa cha cc Chc danh...................................................................................25020.2.2. Cc chc danh c nh ngha sn .............................................................................250

20.2.3. Sa cha cc chc danh..............................................................................................251

20.2.4. Gn cc chc danh ......................................................................................................25220.2.5. Thit lp chc danh mc nh ......................................................................................25220.2.6. Enable v Disable cc chc danh..................................................................................25320.2.7. Thu hi cc chc danh t cc user ...............................................................................25420.2.8. Xo cc chc danh ......................................................................................................254

20.3. THNG TIN V CC CHC DANH..............................................................................254

CHNG 21. TNH NNG H TR NGN NG QUC GIA ....................... 25621.1. NGN NG QUC GIA..............................................................................................256

21.1.1. Cc c im chnh .....................................................................................................25621.1.2. Chn tp k t cho database ........................................................................................256

21.1.3. Tp k t v tp k t quc gia ca database.................................................................25721.2. CC THAM S NLS....................................................................................................258

21.2.1. La chn tham s .......................................................................................................25821.2.2. Ngn ng ph thuc v gi tr territory mc nh ..........................................................25921.2.3. Xc nh cc bin mi trng.......................................................................................25921.2.4. Ch nh c trng ngn ng (Language-Dependent) cho tng session ..........................26021.2.5. Tham s NLS v cc hm SQL......................................................................................261

21.3. THNG TIN V CC GI TR NLS C KHI TO .................................................26321.3.1. Thng tin v tp k t s dng ....................................................................................26321.3.2. Thng tin v cc thit lp thng s NLS........................................................................263


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Chng 1. CC IM MI TRONG ORACLE 9i

Phin bn Oracle9iRelease 1 (9.0.1) c a ra th trng vo u nm 2001 v c citin, b sung thm mt s chc nng, c im mi. Cc c im ny lm cho vicqun l database tr nn mm do, linh hot v hiu qu hn. Di y, ta s xem xt mt

s c im mi ny:

Cho php nh ngha li cu trc ca tables ang online

Chc nng ny c cung cp trong gi package DBMS_REDEFINITION do Oracle cungcp, cho php ngi dng c th nh ngha li cu trc ca mt table thng quan cu lnhDML ngay khi n ang online. Vi cc phin bn trc, Oracle 8i, ta cng c th nh nghali cu trc ca table nhng trc cn phi t ch offline cho n. iu ny khngthun tin cho vic qun tr.

Cho php thc hin lnhANALYZE VALIDATE STRUCTURE tc thiC th thc hin lnh ANALYZE ti u table ngay c khi ang c lnh DML thc hin trntable.

iu khin lu tr sau

Oracle cung cp c ch iu khin switching i vi cc online redo log group da theo thigian (time-based). Trong cu hnh primary/standby, tt c cc noncurrent logs tiprimary site s c lu tr ri vn chuyn ti standby database. Vic ny s hiu qu khihn ch s lng cc redo records.

Tm treo database

Oracle9i cung cp chc nng suspend/resume. Qun tr vin s dng lnh ALTERSYSTEM SUSPEND tm treo database, dng mi thao tc truy xut vo ra i vi ccdatafiles v control files. Khi database trng thi tm treo, cc thao tc vo ra (I/Ooperations) ang thc hin s c kt thc v nhng truy cp vo database mi phtsinh s c y vo queue. Thc hin lnh ALTER SYSTEM RESUME khi phc li tnhtrng bnh thng ca database.

t ch hot ng tnh cho databaseOracle9icho php a database vo ch hot ng tnh(quiesced state). Theo ch ccc DBA transactions, queries, v cc lnh PL/SQL l c php thc hin. Trng thi nycho php ngi dng thc hin cc thao tc qun tr mt cch an ton. S dng cu lnhALTER SYSTEM QUIESCE RESTRICTED a database v ch hot ng tnh.

Kh nng khi phc v cp pht li khng gian

Oracle s t ng thc hin tm treo (suspending) v sau khi phc (resuming) li victhc hin cc thao tc database tn km (large database operations) trong trng hp c li

cp pht khng gian. Nh vy m Oracle database server s c th t thc hin cc thao tchp l thay v vic tr v thng bo li nh cc phin bn trc. Sau khi cc li ny ckhc phc database li c t ng khi phc bnh thng.


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Cho php lu tr trn nhiu ch lu tr

S lng ch lu tr ti a m ta c th s dng lu tr cc online redo log c tngln t 5 ti 10.

T ng qun l vng khng gian

Oracle9icho php qun l t ng vic gii phng v s dng cc vng khng gian c trongcc segments c lu tr trong cc locally managed tablespaces thng qua vic s dngmnh SEGMENT SPACE MANAGEMENT c trong cu lnh CREATE TABLESPACE. Quntr vin c th s dng ch AUTO hoc MANUAL ch r kiu qun l khng gian mOracle s s dng.

Cp nht li cc global indexes mi khi thc hin thao tc bo tr partition

Theo mc nh, c th c mt vi phn ca mt bng c phn khu (partitioned tables)

trng thi khng s dng (nh du UNUSABLE) s c np vo trong global indexes. Vta cn xy dng li (rebuild) ton b global index. Oracle9icho php thc hin t ng cngvic rebuild ny thng qua mnh UPDATE GLOBAL INDEX c trong cu lnh ALTERTABLE khi thc hin bo tr.

Cho php s dng ng thi nhiu kch c block

Oracle cho php s dng ng thi nhiu kch c blocks (multiple block sizes). Kch thcchun (standard block size) c quy nh trong tham s khi to DB_BLOCK_SIZE nhngcng c th m rng thm 4 gi tr kch thc block phi chun na (nonstandard block

sizes). Cc kch thc blocks phi chun c ch r mi khi to tablespaces. Kch thc blockchun c s dng cho SYSTEM tablespace v hu ht cc tablespaces khc. Vic h tr sdng nhiu kch c block s cho php thc hin trao i cc tablespaces ca cc databasem khng c cng mt kch thc block.

Qun l ng buffer cache

Kch thc ca buffer cache c trong vng nh System Global Area c qun l ng. iuny c ngha l gi tr ca tham sDB_BLOCK_BUFFERS (trong file tham s khi to) c thc thay th bi gi tr c trong tham s khc, tham sDB_CACHE_SIZE. Trong Oracle 9i,buffer cache li c phn chia thnh nhiu b m con (subcaches) nu c s dng ch

multiple block sizes. Bn gi tr kch c block c ch ra trong 4 tham s DB_nK_CACHE_SIZE tng ng .

Qun l ng vng nh SGA

Cc tham s khi to c th tc ng ti kch c ca vng nh SGA. V ta c th thay ikch c ca SGA d dng thng qua cu lnh ALTER SYSTEM SET.

Qun l vic khi phc (undo) t ng

Oracle s dng rollback segments lu tr cc thng tin cho khi phc. Vic phc hi(undo) bao gm roll back, undo, v thay i (changes) i vi database mi khi cn. Oracle9i cho php ta to ring mt undo tablespace lu tr cc thng tin phc hi ny. Vic s


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dng undo tablespace s lm gim bt tnh phc tp ca vic qun tr vng khng gianrollback segment, v cho php phc hi li cc thng tin di m khng s b trng ln nhau.

Qun l files trong Oracle

Mt im mi trong Oracle 9i l qun l files. Thng qua cc tham s khi to

DB_CREATE_FILE_DEST v DB_CREATE_ONLINE_LOG_DEST_ n ta c th ch ra cho hthng cc ng dn c th lu tr cc file thuc tablespace, online redo log file hay controlfile. Oracle lun m bo qun l file duy nht trong h thng.

T ng xo cc datafiles

Oracle9icung cp mt la chn cho php t ng xo b (remove) cc datafiles mi khitablespace tng ng b hu thng qua cu lnh DROP TABLESPACE. Tu chn tng ttrong cu lnh ALTER DATABASE TEMPFILE cng c s dng xo cc temporary filetng ng.

Metadata API

Mt PL/SQL package mi, DBMS_METADATA.GET_DDL, c a vo Oracle 9i cho php taly c cc siu d liu (metadata) Cc thng tin tng hp v cc schema object.

Cc bng ngoi - External tables

Oracle9icho php ta truy cp theo kiu ch c cc d liu trong cc bng ngoi (externaltables). External tables l cc tables m khng nm trong database, v c th cc khundng (format) no . Cu lnh CREATE TABLE ... ORGANIZATION EXTERNAL c

s dng ch ra metadata m t cho external table tng ng. Oracle cung cp iu khintruy cp ORACLE_LOADER, qua cung cp kh nng nh x d liu tng ng vi c phplnh trong control file.

Tng cng cho constraint

Ta s dng mnh USING INDEX trong cu lnh CREATE TABLE hay ALTER TABLE cho php ta ch r index mi khi s dng rng buc unique key hay primary key. Thm vo, ta cng c th ngn cn vic hu (dropping).

File tham s trn serverOracle lu tr cc tham s khi to cho session trong file tham s di khun dng vn bnv c t ti cc client machine.

Cc tham s khi to ca server nm trong file tham s trn server thng khun dngnh phn v c th c lu trong database.

Temporary tablespace mc nh

C th thm vo mnh mi DEFAULT TEMPORARY TABLESPACE vo cu lnh CREATEDATABASE cho php to temporary tablespace ngay trong thi gian to database.Tablespace ny s c s dng nh temporary tablespace mc nh.


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t tn cho transaction

Oracle cho php ta gn tn cho mi mt transaction. Tn ca transaction rt c ch cho vicphn bit gim thiu vic nhm ln gia cc transactions.

Mt s thay i trong Oracle Database Configuration Assistant

Oracle Database Configuration Assistant c mt s thay i trong thit k. Theo , n cungcp cc mu (templates) gip cho vic tit kim, gim bt vic nh ngha cc object trongdatabase.

Ngi dng cng c th to ra cc mu ny thng qua vic sa i cc mu c sn. Khi todatabase bng cng c Database Configuration Assistant ta cng c th thm vo ngay hocsau cc khun mu gi l cc Oracles new Sample Schemas. Nhng schemas ny lnhng v d ti liu c bn trong Oracle.

Qun l vic s dng index

Ta thm mnh MONITORING USAGE vo trong cu lnh ALTER INDEX c th xcnh v qun l index khi n c thc hin.

Lit k cc phn vng

Oracle 9i gii thiu s dng lit k cc phn vng, n cho php ta ch ra mt danh sch ccgi tr ri rc tng ng vi cc partitioning column ca mi phn vng. Phng thc lit kphn vng (list partitioning method) c a ra nhm mc ch m hnh ho d liu phntn i vi cc gi tr ri rc. Vic ny kh thc hin c bng cc phng php rangepartitioning (phn khu theo khong gi tr) hay hash partitioning (phn khu theo hm bm).

Phn khu theo hm bm cho cc index-organized tables

Oracle 9i cho php s dng phng php bm khi phn khu cc index-organized tables. cc phin bn trc, vic phn khu cho index-organized tables vn thc hin c nhng chbng phng php range method.

X l cc job queue process linh hot

Cc job queue process c to mt cch linh hot v n ch cn ti s hiu ca processesc to thc hin cc jobs ca process ang sn sng cho vic thc hin. Tin trnh

nn (background process) c tn l CJQ s m nhim cng vic ny.

im mi trong Database Resource Manager

C mt s chc nng mi c thm vo Database Resource Manager:

C kh nng to mt active session pool, l ni lu cha c mt s lng ln nhtcc user sessions ng thi ang c thc hin. Nu c nhiu hn s lng ln nhtcc sessions cng c thc hin th cc sessions mi ny s c a vo hng i ch thc hin sau. Tuy nhin ta cng c th a ra mt khong thi gian tr(timeout) cho php thc hin hay hu vic thc hin cc sessions mi b sungny.

T ng chuyn users t mt nhm ny sang mt nhm khc tu theo s iu chnhca qun tr vin (administrator). Nu mt session c to bi member thuc mtnhm users no thc hin trong khong thi gian di hn thi gian cho php th


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session c th c t ng chuyn sang mt nhm khc vi nhng yu cu tinguyn khc.

C kh nng ngn chn thc hin cc thao tc m c d kin l s phi chy trongmt thi gian di hn l khong thi gian cho php.

C kh nng to mt undo pool, l ni cha mt s lng nht nh vng khng giandnh cho vic khi phc thng tin (undo).

C ch xc thc v nh xc thc (Proxy authentication and authorization)

Oracle9icho php mt server nm lp gia (middle-tier) xc nhn h mt client. Ta c ththc hin vic ny bng cch a vo mnh GRANT CONNECT THROUGH trong cu lnhALTER USER. Ta cng c th ch r vai tr ca lp gia (middle tier) trong vic kt ni ticlient.

Application roles

Oracle cho php gn roles cho cc application users m c kch hot bng cch s dngPL/SQL package. S dng mnh IDENTIFIED USING package trong cu lnh CREATEROLE thc hin vic ny.


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Chng 2. CC THNH PHN KIN TRC

2.1. KIN TRC ORACLE SERVER

Oracle server l mt h thng qun tr c s d liu i tng-quan h cho php qun lthng tin mt cch ton din. Oracle server bao gm hai thnh phn chnh l Oracle instancev Oracle database.

2.1.1. Oracle Instance

Oracle instance bao gm mt cu trc b nh System Global Area (SGA) v ccbackground processes (tin trnh nn)c s dng qun tr c s d liu. Oracleinstance c xc nh qua tham s mi trng ORACLE_SID ca h iu hnh.

Backgroundprocess

Hnh v 1. Kin trc Oracle Server

System Global Area - SGA

SGA l vng b nh chia s c s dng lu tr d liu v cc thng tin iu khin caOracle server. SGA c cp pht (allocated) trong b nh ca my tnh m Oracle serverang hot ng trn . Cc User kt ni ti Oracle s chia s cc d liu c trong SGA, vicm rng khng gian b nh cho SGA s lm nng cao hiu sut ca h thng, lu tr cnhiu d liu trong h thng hn ng thi gim thiu cc thao tc truy xut a (disk I/O).

SGA bao gm mt vi cu trc b nh chnh:

Shared pool: L mt phn ca SGA lu cc cu trc b nh chia s.

Database buffer cache: Lu tr cc d liu c s dng gn nht. Redo log buffer: c s dng cho vic d tm li cc thay i trong c s d liu vc thc hin bi cc background process.

chi tit hn, ta s xem xt c th tng thnh phn.

Share Pool

Shared pool l mt phn trong SGA v c s dng khi thc hin phn tch cu lnh (parsephase). Kch thc ca Shared pool c xc nh bi tham s SHARED_POOL_SIZE ctrong parameter file (file tham s).

Cc thnh phn ca Shared pool gm c: Library cache v Data dictionary cache.


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Hnh v 2. Cu trc Share Pool

Library Cache

Library cache lu tr thng tin v cc cu lnh SQL c s dng gn nht bao gm:

Ni dung ca cu lnh dng text (vn bn).

Parse tree (cy phn tch) c xy dng tu thuc vo cu lnh. Execution plan (s thc hin lnh) gm cc bc thc hin v ti u lnh.

Do cc thng tin trn c lu tr trong Library cache nn khi thc hin li mt cu lnhtruy vn, trc khi thc hin cu lnh, Server process s ly li cc thng tin c phntch m khng phi phn tch li cu lnh. Do vy, Library cache c th gip nng cao hiusut thc hin lnh.

Data Dictionary Cache

Data dictionary cache l mt thnh phn ca Shared pool lu tr thng tin ca dictionarycache c s dng gn nht nh cc nh ngha cc bng, nh ngha cc ct, usernames,passwords, v cc privileges (quyn).

Trong giai on phn tch lnh (parse phase), Server process s tm cc thng tin trongdictionary cache xc nh cc i tng trong cu lnh SQL v xc nh cc mcquyn tng ng. Trong trng hp cn thit, Server process c th khi to v np ccthng tin t cc file d liu.

Data buffer cacheKhi thc hin mt truy vn, Server process s tm cc blocks cn thit trong database buffercache. Nu khng tm thy block trong database buffer cache, Server process mi c cc

block t data file v to lun mt bn sao ca block vo trong vng nh m (buffercache). Nh vy, vi cc ln truy xut ti block sau ny s khng cn thit phi truy xutvo datafile na.

Hnh v 3. Database buffer cache


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Database buffer cache l vng nh trong SGA s dng lu tr cc block d liu c sdng gn nht. Tng t nh kch thc ca blocks d liu c xc nh bi tham sDB_BLOCK_SIZE, kch thc ca vng m trong buffer cache cng c xc nh bitham sDB_BLOCK_BUFFERS.

Oracle server s dng gii thut least recently used (LRU) algorithm lm ti li vngnh. Theo , khi np mi mt block vo b m, trong trng hp b m y, Oracle

server s loi bt block t c s dng nht ra khi b m np block mi vo b m.

Redo log buffer

Server process ghi li cc thay i ca mt instance vo redo log buffer, y cng l mtphn b nh SGA.

Hnh v 4. Redo log buffer

C mt s c im cn quan tm ca Redo log buffer:

Kch thc c xc nh bi tham sLOG_BUFFER. Lu tr cc redo records (bn ghi hi phc) mi khi c thay i d liu. Redo log buffer c s dng mt cch thng xuyn v cc thay i bi mt

transaction c th nm an xen vi cc thay i ca cc transactions khc. B m c t chc theo kiu circular buffer (b m ni vng) tc l d liu thay

i s tip tc c np ln u sau khi vng m c s dng ht.

Background process

Background process (cc tin trnh nn) thc hin cc chc nng thay cho li gi tin trnhx l tng ng. N iu khin vo ra, cung cp cc c ch x l song song nng cao hiu

qu v tin cy. Ty theo tng cu hnh m Oracle instance c cc Background processnh:

Database Writer (DBW0): Ghi li cc thay i trong data buffer cache ra cc file dliu.

Log Writer (LGWR): Ghi li cc thay i c ng k trong redo log buffer vo ccredo log files.

System Monitor (SMON): Kim tra s nht qun trong database. Process Monitor (PMON): Dn dp li ti nguyn khi cc tin trnh ca Oracle gp li. Checkpoint Process (CKPT): Cp nht li trng thi ca thng tin trong file iu khin

v file d liu mi khi c thay i trong buffer cache.


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Database Writer (DBW0)

Server process ghi li cc d liu thay i rollback v d liu ca cc block trong buffer

cache. Database writer (DBWR) ghi cc thng tin c nh du thay i t database buffercache ln cc data files nhm m bo lun c khong trng b m cn thit cho vic sdng.

Hnh v 5. Database Writer (DBWR)

Vi vic s dng ny, hiu sut s dng database s c ci thin do Server processes chto cc thay i trn buffer cache, DBWR ghi d liu vo cc data file cho ti khi:

S lng buffers nh b du t ti gi tr ngng. Tin trnh duyt tt c buffer m vn khng tm thy d liu tng ng. Qu thi gian quy nh.

Log Writer

Log Writer (LGWR) l mt trong cc background process c trch nhim qun l redo logbuffer ghi li cc thng tin trong Redo log buffer vo Redo log file. Redo log buffer l bm d liu c t chc theo kiu ni vng.


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Hnh v 6. Log Writer (LGWT)LGWR ghi li d liu mt cch tun t vo redo log file theo cc tnh hung sau:

Khi redo log buffer y Khi xy ra timeout (thng thng l 3 giy) Trc khi DBWR ghi li cc blocks b thay i trong data buffer cache vo cc data

files. Khi commit mt transaction.

System Monitor (SMON)

Tin trnhsystem monitor (SMON)thc hin phc hi cc s c (crash recovery) ngay ti thiim instance c khi ng (startup), nu cn thit. SMON cng c trch nhim dn dpcc temporary segments khng cn c s dng na trong dictionary-managedtablespaces. SMON khi phc li cc transactions b cht mi khi xy ra s c. SMON u nthc hin kim tra v khc phc cc s c khi cn.

Trong mi trng Oracle Parallel Server, SMON process ca mt instance c th thc hinkhi phc instance trong trng hp instance hay CPU ca my tnh gp s c.

Process Monitor (PMON)

Tin trnhprocess monitor (PMON)thc hin tin trnh phc hi mi khi c mt user processgp li. PMON c trch nhim dn dp database buffer cache v gii phng ti nguyn muser process s dng. V d, n thit lp li (reset) trng thi ca cc bng ang thchin trong transaction, gii phng cc locks trn bng ny, v hu b process ID ca n rakhi danh sch cc active processes.

PMON kim tra trng thi ca ni gi (dispatcher ) v cc server processes, khi ng li(restarts) mi khi xy ra s c. PMON cng cn thc hin vic ng k cc thng tin vinstance v dispatcher processes vi network listener.

Tng t nhSMON, PMON c gi n mi khi xy ra s c trong h thng.


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Checkpoint Process (CKPT)

Cp nht li trng thi ca thng tin trong file iu khin v file d liu mi khi c thay itrong buffer cache. Xy ra checkpoints khi:

Tt c cc d liu trong database buffers b thay i tnh cho n thi imcheckpointed s c background process DBWRn ghi ln data files.

Background process CKPT cp nht phn headers ca cc data files v cc controlfiles.

Checkpoints c th xy ra i vi tt c cc data files trong database hoc cng c th xyra vi mt data files c th.

Checkpoint xy ra theo cc tnh hung sau:

Mi khi c log switch Khi mt shut down mt database vi cc ch tr ch abort Xy ra theo nh thi gian quy nh trong cc tham s khi to

LOG_CHECKPOINT_INTERVAL v LOG_CHECKPOINT_TIMEOUT Khi c yu cu trc tip ca qun tr vin

Thng tin v checkpoint c lu tr trong Alert file trong trng hp cc tham s khi toLOG_CHECKPOINTS_TO_ALERT c t l TRUE. V ngc li vi gi tr FALSE.

2.1.2. Oracle database

Oracle database l tp hp cc d liu c xem nh mt n v thnh phn (Unit).Database c nhim v lu tr v tr v cc thng tin lin quan. Database c xem xt dihai gc cu trc logicv cu trc vt l . Tuy vy, hai cu trc d liu ny vn tn titch bit nhau, vic qun l d liu theo cu trc lu tr vt l khng gy nh hng ti cutrc logic

Oracle database c xc nh bi tn mt tn duy nht v c quy nh trong tham sDB_NAME ca parameter file.

Hnh v 7. Cu trc database


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Cu trc vt l database

Cu trc vt l bao gm tp hp cc control file, online redo log file v cc datafile:

Datafiles

Mi mt Oracle database u c th c mt hay nhiu datafiles. Cc database datafiles chaton b d liu trong database. Cc d liu thuc cu trc logic ca database nh tableshay indexes u c lu tr di dng vt l trong cc datafiles ca database.

Mt s tnh cht ca datafiles:

Mi datafile ch c th c s dng trong mt database. Bn cnh , datafiles cng cn c mt s tnh cht cho php t ng m rng kch

thc mi khi database ht ch lu tr d liu. Mt hay nhiu datafiles to nn mt n v lu tr logic ca database gi l

tablespace. Mt datafile ch thuc v mt tablespace.

D liu trong mt datafile c th c ra v lu vo vng nh b m ca Oracle. V d: khimt user mun truy cp d liu trong mt table thuc database. Trong trng hp thng tinyu cu khng c trong cache memory hin thi, n s c c trc tip t cc datafiles rav lu tr vo trong b nh.

Tuy nhin, vic b sung hay thm mi d liu vo database khng nht thit phi ghi ngayvo cc datafile. Cc d liu c th tm thi ghi vo b nh gim thiu vic truy xut tib nh ngoi ( a) lm tng hiu nng s dng h thng. Cng vic ghi d liu ny cthc hin bi DBWnbackground process.

Redo Log Files

Mi Oracle database u c mt tp hp t 02 redo log filestr ln. Cc redo log files trongdatabase thng c gi l database's redo log. Mt redo log c to thnh t nhiu redoentries (gi l cc redo records).

Chc nng chnh ca redo log l ghi li tt c cc thay i i vi d liu trong database.Redo log files c s dng bo v database khi nhng hng hc do s c. Oracle chophp s dng cng mt lc nhiu redo log gi l multiplexed redo log cng lu tr ccbn sao ca redo log trn cc a khc nhau.

Cc thng tin trong redo log file ch c s dng khi phc li database trong trnghp h thng gp s c v khng cho php vit trc tip d liu trong database ln ccdatafiles trong database. V d: khi c s c xy ra nh mt in bt cht chng hn, cc dliu trong b nh khng th ghi trc tip ln cc datafiles v gy ra hin tng mt d liu.Tuy nhin, tt c cc d liu b mt ny u c th khi phc li ngay khi database c mtr li. Vic ny c th thc hin c thng qua vic s dng ngay chnh cc thng tin minht c trong cc redo log files thuc datafiles. Oracle s khi phc li cc database cho nthi im trc khi xy ra s c.

Cng vic khi phc d liu t cc redo log c gi l rolling forward.

Control Files

Mi Oracle database u c t nht mt control file. Control file cha cc mc thng tin quy

nh cu trc vt l ca database nh: Tn ca database. Tn v ni lu tr cc datafiles hay redo log files.


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Time stamp (mc thi gian) to lp database, ...

Mi khi no mt instance ca Oracle database c m, control file ca n s c s dng xc nh data files v cc redo log files i km. Khi cc thnh phn vt l c database bthay i (v d nh, to mi datafile hay redo log file), Control file s c t ng thay itng ng bi Oracle.

Control file cng c s dng n khi thc hin khi phc li d liu.

Cu trc logic databse

Cu trc logic ca Oracle database bao gm cc i tng tablespaces, schema objects,data blocks, extents, v segments.

Tablespaces

Mt database c th c phn chia v mt logic thnh cc n v gi l cc tablespaces,Tablespaces thng bao gm mt nhm cc thnh phn c quan h logic vi nhau.

Databases, Tablespaces, v DatafilesMi quan h gia cc databases, tablespaces, v datafiles c th c minh ho bi hnh vsau:

Hnh v 8. Quan h gia database, tablespace v datafile

C mt s im ta cn quan tm:

Mi database c th phn chia v mt logic thnh mt hay nhiu tablespace. Mi tablespace c th c to nn, v mt vt l, bi mt hoc nhiu datafiles. Kch thc ca mt tablespace bng tng kch thc ca cc datafiles ca n. V d:

trong hnh v trn SYSTEM tablespace c kch thc l 2 MB cn USERS tablespacec kch thc l 4 MB.

Kch thc ca database cng c th xc nh c bng tng kch thc ca cctablespaces ca n. V d: trong hnh v trn th kch thc ca database l 6 MB.

Schema v Schema Objects

Schema l tp hp cc i tng (objects) c trong database. Schema objects l cc cutrc logic cho php tham chiu trc tip ti d liu trong database. Schema objects baogm cc cu trc nh tables, views, sequences, stored procedures, synonyms, indexes,clusters, v database links.


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Cc cu trc vt l khc

Ngoi ra, Oracle Server cn s dng cc file khc lu tr thng tin. Cc file bao gm:

Parameter file: Parameter file ch ra cc tham s c s dng trong database. Ngiqun tr database c th sa i mt vi thng tin c trong file ny. Cc tham strong parameter file c vit dng vn bn.

Password file: Xc nh quyn ca tng user trong database. Cho php ngi s dngkhi ng v tt mt Oracle instance. Archived redo log files: L bn off line ca cc redo log files cha cc thng tin cn

thit phc hi d liu.

2.1.3. Qun tr c s d liu Oracle

Qun tr c s d liu l cng vic bo tr v vn hnh Oracle server n c th tip nhnv x l c tt c cc yu cu (requests) t pha Client. lm c iu ny, ngiqun tr vin c s d liu cn phi hiu c kin trc ca Oracle database.

2.1.4. Thit lp cc tham s khi to nh hng ti kch c b nh SGA

Tham s khi to nh hng ti kch thc b nh cp pht cho vng System Global Area.Ngoi tr tham sSGA_MAX_SIZE, cn li cc tham s khc u l tham s ng tc l cth thay i gi tr ca chng ngay trong lc database ang chy thng qua cu lnh ALTERSYSTEM. Kch thc ca SGA cng c th thay i c trong qu trnh chy database.

Thit lp tham s cho Buffer Cache

Tham s khi to buffer cache quy nh kch thc ca buffer cache l mt phn ca SGA. .

Ta s dng cc tham sDB_CACHE_SIZE v mt trong nhng tham sDB_nK_CACHE_SIZE cho php s dng ch multiple block sizes i vi database. Oracle s t ng gncc gi tr mc nh cho tham s the DB_CACHE_SIZE, cn tham sDB_nK_CACHE_SIZE sc gn mc nh bng 0.

Kch thc ca buffer cache s c nh hng nhiu ti hiu sut thc hin ca h thng.Kch thc cng ln th cng gim bt vic c v ghi a. Tuy nhin, kch thc ca cacheln s tn nhiu b nh v s c nhiu tn km trong vic thc hin paging (phn trang)hay swapping (trao i) b nh.

Tham s DB_CACHE_SIZE

Tham s khi to DB_CACHE_SIZE c s dng thay th cho tham sDB_BLOCK_BUFFERSca cc phin bn Oracle trc kia. Tham sDB_CACHE_SIZE quy nh kch thc ca blockbuffers chun. Kch thc ca mt block chun li c quy nh trong tham sDB_BLOCK_SIZE.

Tuy vy, tham sDB_BLOCK_BUFFERS vn c s dng tng thch vi cc phin bntrc, tuy nhin gi tr ca n khng c s dng cho cc tham s ng.

Tham s DB_nK_CACHE_SIZE

Ch ra kch c l bi s nguyn ln kch thc ca block buffers. N c ch ra bi cc thams:

DB_2K_CACHE_SIZE


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DB_4K_CACHE_SIZE

DB_8K_CACHE_SIZE

DB_16K_CACHE_SIZE

DB_32K_CACHE_SIZE.

Mi tham s ch ra kch c ca buffer cache tng ng vi kch c ca block.V d:

DB_BLOCK_SIZE=4096

DB_CACHE_SIZE=12M

DB_2K_CACHE_SIZE=8M

DB_8K_CACHE_SIZE=4M

v d ny, cc tham s ch ra kch thc block chun ca database l 4K. Kch thc cachetng ng vi kch thc block chun l 12M. Cc kch thc m rng ca cache l 2K v 8Ks c t li vi gi tr tng ng l 8M v 4M.

iu chnh kch c ca Shared Pool

Tham sSHARED_POOL_SIZE trong phin bn Oracle 9i l tham s ng, tc l c th thayi c gi tr ca n (iu ny khng th thc hin c trong cc phin bn trc). Ncho php ta thay i kch thc ca shared pool l mt trong cc thnh phn ca SGA. Theomc nh Oracle cng chn mt gi tr mc nh ph hp cho tham s ny.

iu chnh kch c ca Large Pool

Tng t nhSHARED_POOL_SIZE, tham sLARGE_POOL_SIZE cng l mt tham s ng,

n cho php ta iu chnh kch c ca large pool, y cng l mt thnh phn trong SGA. .

Gii hn kch c ca SGA

Tham sSGA_MAX_SIZE quy nh kch c ln nht ca System Global Area . Ta cng c ththay i kch c ca buffer caches, shared pool v large pool, tuy nhin vic thay i nynn l m rng gi tr kch thc cho cc thnh phn ca SGA. Gi tr m rng thm nycng khng nn t ti ngng ca SGA_MAX_SIZE.

Trong trng hp ta khng ch r gi tr ca SGA_MAX_SIZE th Oracle s t ng gn gi trny bng tng s kch c ca cc thnh phn ca SGA lc ban u.

2.2.KT NI TI ORACLE SERVER

2.2.1. M hnh kt ni

Cc Client c th kt ni ti Oracle Server thng qua 03 cch sau:

Kt ni trc tip: kt ni m Client nm trn cng mt my ch Oracle server. Kt ni hai lp (two-tiered) client-server: Client nm trn mt my tnh khc v kt

ni trc tip ti my ch Oracle Server. Kt ni ba lp (three-tiered): Client nm trn my tnh khc vi my ch Oracle

Server, n giao tip vi mt ng dng hay mt my ch mng (network server) viu khin ng dng hay my ch ny kt ni ti Oracle server.


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Hnh v 9. Kt ni ti Oracle server2.2.2. Mt s khi nim c bn lin quan n kt ni

Connection (lin kt)

Lin kt l ng lin lc gia mt user process v mt Oracle server. Trong trng hpuser s dng cc tool hoc cc ng dng ngay trn cng mt my vi Oracle server, nglin lc s c to lp ngay trn my . Trong trng hp user nm trn mt my khcth lin kt s s dng ng mng kt ni ti Oracle server.

Session (phin)

Mt phin tng ng vi mt lin kt c th ca mt user ti mt Oracle server. Phin btu khi user kt ni ti Oracle Server c kim tra hp l v kt thc khi user thc hinlog out khi Oracle Server hoc user kt thc mt cch bt thng. Mt user cng mt lcc th c nhiu phin lm vic kt ni ti Oracle Server thng qua cc ng dng hay cctool khc nhau. V du: User c th ng thi c cc phin lm vic gia SQL*Plus,Developer/2000 Form,... ti Oracle Server.

Lu : Phin ch to lp c khi Oracle Server sn sng cho vic kt ni ca cc client.

2.2.3. Kt ni ti database

Cc bc thc hin kt ni

kt ni ti database trc tin, cn phi to lin kt ti Oracle Server. Lin kt ti OracleServer c to theo cc bc sau:

User s dng cng c SQL*Plus hay s dng cc cng c khc ca Oracle nhDeveloper/2000 Forms khi to tin trnh. Trong m hnh Client-Server, cc cngc hay ng dng ny c chy trn my Client.

User thc hin log in vo Oracle server vi vic khai bo username, password v tnlin kt ti database. Cc ng dng tools s to mt tin trnh kt ni ti Oracleserver qua cc tham s ny. Tin trnh ny c gi l tin trnh phc v. Tin trnhphc v s giao tip vi Oracle server thay cho tin trnh ca user chy trn myClient.


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V d thc hin kt ni ti database

hiu r hn v cc bc thc hin kt ni, ta hy xem xt mt v d m t vic kt niti Oracle database thc hin bi mt user ti mt my tnh khc c kt ni ti my tnh mOracle server ang chy trn . Vic kt ni c thc hin thng qua ng mng bngcch s dng dch v Oracle Net8.

1. Ti my ch, cn m bo Oracle server ang chy v sn sng n nhn cc tnhiu t pha Client. My ch ny c gi l hosthay database server.

2. Ti mt my trm c chy cc ng dng (gi l local machinehay client workstation)s thc hin cc user process kt ni ti database. Client application thc hinthit lp mt kt ni ti server thng qua Net8 driver.

3. My ch server trn c cc Net8 driver. Server s thc hin vic nghe v d tmtt c cc yu cu gi n t pha client v sau s to mt server process tngng vi user process.

4. Khi user thc hin mt cu lnh SQL hay commit mt transaction. V d nh user dliu trn mt dng trong mt table.

5. Server process s nhn v cu lnh gi ti t Client, kim tra v phn tch cu lnh,vic ny c thc hin trong shared pool. Tip theo , Server process s kim traquyn truy nhp d liu ca user.

6. Server process tr v cc gi tr d liu yu cu t cc d liu c trong datafile haytrong system global area.

7. Server process thay i cc d liu c trong system global area. DBWnprocess ghi licc blocks thay i ra a. LGWR process s ghi li ngay lp tc cc bn ghithay i vo online redo log file ngay khi transaction c commit.

8. Trong trng hp transaction thc hin thnh cng, server process s gi thng bohon tt qua ng mng ti Client. Ngc li, s c mt error message gi tiClient.


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Chng 3. CC CNG C QUN TR ORACLE

3.1.CC CNG CQUN TRCSDLIU ORACLE

Oracle hin ti cung cp rt nhiu cng c cho php qun tr c s d liu. C th k rasau y mt s cng c c bn sau:

Cng c Din gii

Server Manager LineMode

Cng c qun tr c s d liu Oracle theo ch dng lnh nhstart (khi ng), shutdown (dng) database,...

SQL*Plus Line Mode y l mt tin ch s dng cho vic cng qun tr nh startingup, shutting down, hoc phc hi database.

Oracle EnterpriseManager

L cng c c giao din ha thc hin vic qun tr, iukhin v thay i mt hoc nhiu database.

SQL*Loader Tin ch s dng np cc file bn ngoi vo trong cc bng

ca Oracle .Cng c Export vImport

Tin ch s dng exporting hoc importing d liu theo khundng ca Oracle.

Password File Tin ch s dng to file mt khu trong database.

thun tin, ti liu s trnh by hai cng c thng dng nht qun tr c s d liul:

Server Manager Line Mode Oracle Enterprise Manager

3.2.SERVER MANAGER LINE MODE

3.2.1. Truy nhp Server Manager Line Mode

User (ngi s dng) c th vo Server Manager Line Mode theo hai cch:

C:\svrmgrl

Cch ny ch vo Server Manager Line Mode m cha thc hin kt ni c th ti database

Lu : trong cc phin bn c, ta g svrmgrl30 thay v svrmgrl

Hoc:

C:\svgrmrl command=connect internal/admin

C:\svgrmrl command=@c:\example.sql

Vo Server Manager Line Mode ng thi thc hin lnh lun.

K t s dng trong Server Manager Line Mode

Vi Server Manager Line Mode, ta c th thc hin cu lnh SQL hoc on lnh PL/SQL.Cc cu lnh c kt thc bi k t chm phy ;

S dng k t / kt thc cu lnh trong trng hp bm phm Enter xung dng.

Ngoi ra, ta c th chy file script cha cc cu lnh SQL v PL/SQL. Bng cch s dng kt @ trc tn file script.


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3.2.2. Phn nhm cc lnh trong Server manager

Loi lnh Tn lnh

Lnh khng cn ktni ti database

EXIT

REMARK

SET

SHOWSPOOL

Cc lnh cn nmc quyn truynhp

CONNECT/DISCONNECT

DESCRIBE

EXECUTE

SHOW ERRORS

SHOW PARAMETER

SHOW SGA

Cc lnh cn nmc quyn truynhp c bit

CONNECT AS SYSDBA

CONNECT AS SYSOPERARCHIVE LOG

RECOVER DATABASE

STARTUP/SHUTDOWN

3.2.3. Din gii cc lnh trong Server manager

Tn lnh Din gii

EXIT ng SQL Worksheet, thot khi Server Manager

REMARK Thm vo li ch dn, thng hay s dng trong file SQL scriptSET Thit lp hoc thay i cc tnh cht c trong phin lm vic hin

thi.

SHOW Hin th cc thit t hin thi

SPOOL Cho php hoc thi cho php chuyn hng kt xut d liu ra file

CONNECT/

DISCONNECT

Kt ni hoc hu kt ni ti database

DESCRIBE Xem cu trc ca mt function, package, package body, procedure,table, object, view

EXECUTE Thc hin mt dng lnh PL/SQL

SHOW ERRORS Hin th cc li pht sinh ca th tc, hm hay package

SHOW PARAMETER Hin th gi tr hin thi ca mt hay nhiu tham s khi to

SHOW SGA Hin th thng tin v SGA ca Instance hin thi

CONNECT/AS

SYSDBA

Kt ni ti database vi c quyn qun tr

ARCHIVE LOG Khi ng v dng vic lu tr t ng i vi cc file online redolog files, redo log file

RECOVER

DATABASE

Phc hi li mt hay nhiu tablespaces


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STARTUP/

SHUTDOWN

Khi ng hoc tt Oracle instance

3.3.ORACLE ENTERPRISE MANAGER

Oracle Enterprise Manager (OME) l phng tin cho php c c ci nhn tng th v tonb h thng. Trong c cy phn cp v cc hnh nh ha v cc i tng v quan hgia chng trong h thng.

OME c cc tin trnh Intelligent Agent processes cho php qun l t xa cc dch v chung- common services nh jobs, events, mt cch d dng.

OME cng bao gm c nhng ng dng qun l chuyn bit: DBA Management Pack,Advanced Management Packs.

Bn cnh , OME cn cung cp mt lng ln cc hm API cho php tch hp vi cc hthng qun l ng dng khc. Bao gm c cc h thng qun l ca Oracle v khng phica Oracle.

OEM Console c trong c Windows NT v Windows 95.

Hnh v 10.Oracle Enterprise Manager

3.3.1. Kin trc OME

Kin trc OME l m rng ca kin trc Client/Server, n c kin trc ba lp. Lp th nht cha cc Java-based console v cc ng dng tch hp cho php ci t

v chy bi cc Web browser. Lp th hai l Oracle Management Server - OMS. Chc nng chnh ca OMS l x l

v qun tr tt c cc tc v ca h thng, tp trung qun l v phn phi iu khingia cc clients v cc nt iu khin - managed nodes. OEM s dng OracleEnterprise Manager repository duy tr d liu h thng, d liu ng dng v cctrng thi ca cc thc th iu khin phn tn trong h thng, cho php ngi dngc th truy cp v chia s cc vng d liu lu tr.

Lp th ba bao gm cc ch nh databases, nodes v cc dch v qun l khc.


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3.3.2. Cc dch v chung

OEM c cc dch v cho php qun l cc nodes trn mng (network)

Dch v pht hin - Discovery service: OEM t ng pht hin (nh v) tt c ccdatabase v cc dch v chy trn cc nodes, mt khi cc nodes c xc nh. Ccdch v ny bao gm Web servers, listeners, machines, parallel servers, video servers,v cc services khc.

Job Scheduling System: cho php thc hin t ng lp li cc tc v. H thng chophp to v qun l cc jobs, ln k hoch thc hin chng v cho php xem, chia sthng tin xc nh Jobs.

Event Management System: cho php qun l mi trng mng (networkenvironment) x l cc trng hp mt dch v, thiu hoc ht vng lu tr, v ccvn khc nh s dn

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