a0136 oracle dba on unix and linux morebook vn 6519

Oracle DBA on Unix and Linux
Michael Wessler

800 East 96th St., Indianapolis, Indiana, 46240 USA


Oracle DBA on Unix and Linux

ASSOCIATE PUBLISHER

Copyright © 2002 by Sams

Jeff Koch

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Second Printing with corrections: April 2002

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PROOFREADER

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04

7

6

5

4

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Contents at a Glance
Introduction 1
1

Role of the DBA 5

2

Architecture of the Oracle Server 29

3

Planning a Database 63

4

Machine Setup and Installation

5

Creating a Database 111

6

Daily Activities

7

GUI Management Products 175

8

DBA Utilities

9

Backup and Recovery

87

139

203
237

10

When Things Go Wrong 271

11

Oracle Server Tuning 293

12

Unix Operation System Architecture 321

13

Unix Server Monitoring 341

14

Patches and Upgrades

15

Migrations 395

16

Java Inside the Database Server 417

17

Web DB/Oracle Portal

18

Internet Application Server (iAS) 463

19

9i Server New Features 485

20

Growth of the DBA 511

A

Basic Unix Commands

B

vi Editor

C

Scripts

D

Glossary 543
Index

533
537

551

373

437

525


Contents
Introduction
1
Who Should Read This Book? ..........................................................2
What Makes This Book Different? ..................................................3

1

Role of the DBA
5
What Is a DBA? ......................................................................................6
Depends on the Shop ........................................................................6
Where DBAs Come From ................................................................6
Paths to Becoming a DBA ................................................................7
System Administrator (SA) ..............................................................7
Developer/Programmer ....................................................................7
Systems Designer/Data Modeler ......................................................8
Other Paths ........................................................................................8
Types of DBAs ........................................................................................8
Application DBA ..............................................................................8
Systems DBA ....................................................................................8
Maintenance DBA ............................................................................9
Database Administration Principles ........................................................9
Data Protection ..................................................................................9
Data Availability ..............................................................................11
Database Administration Responsibilities ..........................................12
Database Technical Responsibilities ..............................................12
Non-Technical Responsibilities ......................................................16
Skills Needed ..................................................................................18
Roles Within the IT Organization ........................................................22
System Administrators ....................................................................22
Programmers/Developers ................................................................24
Management ....................................................................................24
Customers and End Users ..............................................................25
Outside Organizations ....................................................................26
DBA Mindset ........................................................................................26

Summary ..............................................................................................27

2

Architecture of the
Oracle Server
29
Oracle Products Relating to Database Servers ....................................30
SQL*Plus ........................................................................................31
Server Manager ..............................................................................32
Net8 ................................................................................................32


Oracle DBA on Unix and Linux
Database Versus Instance ......................................................................33
Oracle File Types ..................................................................................34
Control Files ....................................................................................34
Data Files ........................................................................................35
System ............................................................................................36
Data ..................................................................................................36
Index ................................................................................................37
Temp ................................................................................................38
Rollback ..........................................................................................38
Online Redo Logs ............................................................................40
Memory Structures ..............................................................................42
Shared Global Area (SGA) ..............................................................42
Shared Pool ......................................................................................46
Redo Log Buffer ..............................................................................47
Large Pool ......................................................................................48
Java Pool ..........................................................................................48

Oracle Processes ..................................................................................49
Server Processes ..............................................................................50
Background Processes ....................................................................52
System Monitor Process (SMON) ..................................................53
Process Monitor Process (PMON) ..................................................53
Database Writer Process (DBWn) ..................................................53
Log Writer Process (LGWR) ..........................................................54
Checkpoint Process (CKPT) ..........................................................55
Archiver Process (ARCn) ................................................................56
Recover Process (RECO) ................................................................56
Job Queue Processes (SNPnn) ........................................................56
Queue Monitor Processes (QMNnn) ..............................................56
Dispatcher Processes (Dnnn) ..........................................................56
Shared Server Processes (Snnn) ......................................................56
Transaction Control ..............................................................................57
Miscellaneous Database Files ..............................................................59
Oracle Database Parameter and Log Files ......................................59
Summary ..............................................................................................62
3.

Planning a Database
63
System Architecture ..............................................................................64
Two-Tier Basic Client Server Architecture (2 Tier) ........................65
Three-Tier Client Server Architecture ............................................66
Capacity Planning/Sizing ......................................................................67
Optimal Flexible Architecture ..............................................................71

v

582

Unix

filesystems
ext2, 332
free space, 332
iso9660, 333
mount points, 331
mounting, 331-332
nfs, 332
problem solving, 333-334
ufs, 332
unmounting, 333
vxfs, 333
I/O subsystem, 335
kernel, 322-323
memory
pages, 329
paging, 329-330
swap area, 328
swapping, 329-330
thrashing, 329
virtual memory, 328
monitoring, 342-343
CPUs, 362-367
disk I/O, 356-361
importance of, 342
memory, 354-356

network performance,
368-371
shared memory, 344-353
MPPs (Massively Parallel
Processors), 340
NUMAs (NonUniform Memory
Access), 340
processes, 323
creating, 326
initialized data, 325
multitasking, 323
parent processes, 326
priorities, 324
process tables, 324
RT (Real Time), 324
scheduler process, 324
stack, 325
states, 325
SYS (System), 324
text area, 325
TS (Time Share), 324
viewing, 327

shared-everything architecture,
338
shared-nothing architecture,
340
shutdown process, 337
SMP (symmetrical multiprocessor) machines, 338
startup process

run levels, 336
sequence of events, 335-336
uniprocessor machines, 337-338
unmounting filesystems, 333
updating SPFILEs (server
parameter files), 492-493
upgrades
defined, 374-375
example, 388-391
import/export commands, 402
installing, 386-388
ORACLE_HOME directory,
386-387
parameter files, 388
preparation, 385-386
tips and recommendations, 391392
upgrade scripts, 387
when to perform, 375-376
uptime command, 276,
365-366, 530
user dump (udump) files, 74
User Global Area (UGA), 49
user interfaces
Net8, 32-33
Server Manager, 32
SQL*Plus, 31
user-level exports, 205-206
useradd command, 94
USERID export parameter, 206
USERID import parameter, 212

users, 25
creating, 94, 149
groups
creating, 93-94
oinstall, 94
killing, 146, 367
logged-in users, displaying, 531

logging off, 527
MIGRATE, 406
OUTLN, 406
privileges, 149-150
quotas, 151-152
roles, 151, 449-450
USER_X view, 140
utilities. See commands; scripts
UTLBSTAT script, 296-298
UTLESTAT script, 296-298

V
V$ view, 140
V$SESSION_EVENT view,
310-311
V$SESSION_WAIT view, 311
V$SYSTEM_EVENT view, 310
/var/opt/oracle directory, 96
variables, environment
CLASSPATH, 100
DISPLAY, 100-101
displaying, 527

LD_LIBRARY_PATH, 99
NLS_LANG, 99
ORACLE_BASE, 99
ORACLE_HOME, 99
ORACLE_SID, 99
ORA_NLS33, 99
PATH, 100
vendors, capacity-planning
issues, 71
verifying
database instances, 125-127
databases and connectivity,
163-164
Intelligent Agents, 188
Oracle installation, 107-108
Veritas filesystem (vxfs), 333
vi editor, 534
viewing. See displaying
views, 140-141
obtaining descriptions of, 141
obtaining list of, 141
V$SESSION_EVENT, 310-311


Zombie state

V$SESSION_WAIT, 311
V$SYSTEM_EVENT, 310
virtual memory, 328
vmstat command, 355-356, 531

CPU usage statistics, 366
disk I/O monitoring, 361
vxfs (Veritas) filesystem, 333

W
w command, 535
wait events, 309-310
V$SESSION_EVENT view,
310-311
V$SESSION_WAIT view, 311
V$SYSTEM_EVENT view, 310
wall command, 531
wc command, 531
Web architecture, 464-466
availability, 468
clients, 465
database tier, 465
middle tier, 465
scalability, 467-468
technological design, 467
Web cache (iAS), 471-472
Web servers. See servers
Web sites
Java, 420
MetaLink, 378, 514
OCP (Oracle Certified
Professional) program, 517
Oracle University, 513
Perpetual Technologies, 17, 514
Technet, 514

WebDB. See Oracle Portal
WebLogic server, 466
which command, 531
who command, 531
word count, displaying, 531
wq command, 535
wraps (rollback segments), 308

X-Z
x command, 535
yy command, 535
Zombie state, 325

583