© 2010 Quest Software, Inc. ALL RIGHTS RESERVED

Oracle und DB2 LUW

Udo Brede

Solution Architect DB2

Udo.Brede@quest.com

2

Agenda

• Grundlagen und Terminologie

• Architektonische Unterscheidungen

• Storage und Space Management

• Unterscheidungen in der Administration

• Oracle Compatibility Features in DB2 LUW Version 9.7

3

DB2 = Database 2

• 07.06.1983

• DB2 z/OS (MVS, OS/390)

• DB2 VSE/VM

• DB2 auf z/Linux

• DB2/2

• DB2/400 (AS400, I-Series)

• DB2 LUW (Linux, Unix, Windows)

4

Komponenten der DBMS

Oracle

• Instance

• File

• Database

• Tablespace

• Schema

• Table

• Index

• View

• Trigger

• Rollback Segment

• Stored Procedures

• SQL Plus

• Packages

DB2 LUW

• Instance

• Container

• Database

• Tablespace

• Schema

• Table

• Index

• View

• Trigger

• NA

• Stored Procedures

• DB2 CLP

• Modules

5

Produkt Optionen

• Express Edition– 1 CPU/1GB RAM

– 4 GB max DB size

– Nur für Windows/Linux

• Standard Edition– 4 Sockets

– Unlimited scalability

• Enterprise Edition– Unlimited scalability

– Table Partitioning

– RAC

• Express-C– 2 CPU/2GB RAM

– Windows/Linux/Solaris/Mac

• Express Edition– 4 CPU/ 4GB RAM max

• Workgroup Edition– 4 CPUs/ 16 GB RAM

• Enterprise Server Edition– Unlimited scalability

– Data partitioning (DPF)

– Purescale

Oracle DB2

6

System/Data Dictionary - Catalog

• Base tables– SYS.xxxxx$

• System views– SYS.GV_$ or GV$

– SYS.V_$ or V$

– ALL_

– DBA_

– USER_

• Base Tables

– SYSIBM.xxxx

• System Views

– SYSCAT• Read-only views defined for catalog

base tables

– SYSSTAT• Updateable set of views

• Primarily used for access path

manipulation

– Administrative Views

Oracle DB2

7

Zugriff/Datenbankmangement

• OEM - GUI– DBA Mgmt Pack(free)

– Change Mgmt Pack($)

– Diagnostics Pack($)

– Tuning Pack($)

– Recovery Manager($)

• Sqlplus

• Control Center GUI– Command center

– Command line processor

– Command window

– Script center

– Visual Explain

• Data Studio/Optim– Nachfolger vom Control Center

• CLP

Oracle DB2

8

Gleicher Name – verschiedene Erklärung/Nutzung

Oracle

• Stored Procedure

– PL/SQL

• Package

– grouping of PL/SQL blocks

– Nothing to do with optimization

• Segment

– Set of Oracle Extents

DB2

• Stored Procedure

– External - C,Java,Cobol

– Internal, SQL/PL

• Package

– Pre-compiled static SQL

• Segment

– Block of pages in TS

9

Verschiedene Namen – gleiche Nutzung

Oracle

• Package

• Data Block

• Dictionary

• Alert Log

• Redo Log

• Archive log

• Segments

• Statement Cache

• System Global Area

(SGA)

DB2

• Module (9.7)

• Data Page

• Catalog

• Diag log

• Log Files

• Archival Logging

• Space Consuming Objects

• Package Cache

• Instance shared memory/DB

shared memory

10

Instance und Datenbank

Oracle

• Instance– A collection of Processes

– One data dictionary

– one active database

– Init.ora parameter file

DB2

• Instance– Logical database server

environment

– Also referred to as a Node

– 1 to many databases

– Database Manager

Configuration File

11

Instance

DB2

D

B

M

C

O

N

F

I

G

D

B

M

C

O

N

F

I

G

Instance_1

PRODDB1

CatalogDBCONFIG

Log

Catalog

Log

DBCONFIGPRODDB2

BP’s

BP’s

Instance_2

TESTDB1

CatalogDBCONFIG

Log

Catalog

Log

DBCONFIGTESTDB2

BP’s

BP’s

SIDOracle Database

Control

files

Data

files

Redo

log

files

Data

Dictionary

12

Bufferpool

Oracle

• Typically use single BP

• Defined in init.ora

• Dynamic create, alter, and delete

• Objects assigned via DDL

DB2

• IBMDEFAULTBP automatically

created with database

– Additional pools created with DDL

• Hidden Bufferpools

– 4k,8k,16k, & 32K

• Share only within individual

databases

13

Datenbanken

Oracle

• Physical Structure

– Data files

– Redo Log files

– Control files

• Only one DB mounted/opened

• SYSTEM Tablespace

– Data dictionary

DB2

• Logical grouping of DB2 objects

• 1 to many databases/instance

• System tablespaces– SYSCATSPACE

– TEMPSPACE

– USERSPACE

• Bufferpools defined in database

• Database configuration file

14

Storage und Space Management

• Data Files– Cooked

– Raw

– Auto extend

• Container

– Device

– Directory

– File

DB2Oracle

15

Tablespaces

Oracle

– System • Automatically created

– SYSAUX• Auxillary system TS

– UNDO

– Non-System• Permanent

• Temporary

• BIGFILE/SMALLFILE

DB2• Regular

– USERSPACE1

• Temporary

• Large

16

Tablespaces - 2

Oracle

• Dictionary Managed

– No space calculations

• Locally Managed

• Automatic Storage

Management (ASM)

– 10g

DB2

• System Managed (SMS)

– O/S’s file manager allocates

space as needed

– Good for small tables

• Database Managed (DMS)

– Space is pre-allocated

– Better suited for large tables

– Faster I/O

• Automatic

– Combines features of both

SMS and DMS

17

DB2 Tablespaces

• System Managed– No finite storage specified

• O/S’s file manager

allocates space as needed

• Good for small tables

• Database Managed– Space is pre-allocated

– Better suited for large tables

– Faster I/O

Add Containers to TS X

Separate Indexes from Data X

Space allocated as Needed X

High performance in heavy OLTP X

High performance in decision support X X

Ease of administration for small tables X

Flexibility of Administration X

File or Device containers X

SMS DMS

18

Tablespace Komponenten

Segments

Extents

Data Blocks

Data Files

Oracle DB2

Storage Object

Extents

Page

Containers

19

Datenspeicherung

Oracle• Datafile

– Datafiles associated to an individual tablespace

– ‘/DISK6/app04.dbf’

DB2• Containers

– A container is assigned to an individual tablespace

• Directory name

– SMS Only

– D:\MYTS

• Raw Device

– DMS Only

– E:

• File name

– DMS Only

– D:\SODADB\SODA.UTILITY.DMS

20

Partitioning

Oracle

• Table Definition

– 1-64k partitions

– Partitioning on range, hash,

both or list

– Partitions assigned to TS

• Enhances Parallel Query

• Easier Data Management

DB2• Table partitioning

– Partitioning part of table DDL

– Partitions can be in one or multiple tablespaces

– Partitions can be rolled in/out

– Partitions can be administered independently

• Database Partitioning– Database Partitioning

Feature (DPF)• ESE Edition only

– Database is partitioned across multiple servers

– Multiple tables

21

Tabelle

Oracle

– One to many tables

defined in a tablespace

• Tables and Indexes are

independent of each

other

– Index Organized Tables

DB2

– One to many tables

defined in a tablespace

• Indexes directly tied to

table definition

22

Index

Oracle– Unique

– Non-unique

– Partitioning

– Function based

– Bit Map

DB2• Unique

• Non-unique

• Clustering

• Partitioned

23

Index - 2

DB2• Indexes are dependent on tables. Index space must be

specified when table created.

– All indexes for table use 1 tablespace

– Index space is predefined before IX’s are created

– Indexes can be defined in same tablespace as table

24

Administration

25

Optimizer

Oracle

• Cost based

• Rules Based

– Backward compatibility

DB2

• Cost based more

sophisticated than Oracle

– Seven levels of optimization

– Adjusted based on query

complexity

• No Rules

26

Optimizer Class

• DB2 Optimizer Class– Values are between 0 and 9, default is 5

• Determines the intensity used by the DB2 SQL Compiler when rewriting SQL

• Dynamic SQL can’t spend time optimizing, use lower class

• Static SQL optimizes once, use a higher class

• “dft_queryopt” database setting

• SET CURRENT QUEREY OPTIMIZATION n

Level Recommendation

0 Minimal amount of optimization. Only recommended for very simple SQL accessing well indexed tables. Only

nested loop joins and IX scans enabled.

1 Similar to 0 except Merge Scan and TS scan enabled.

2 Recommended for very complex queries which are infrequently executed in a decision support or OLAP

environment.

3 Closest to z/OS optimizer. Recommended for queries with 4 or more joins.

5 DEFAULT – Most cost effective method for mix of simple and complex queries. Optimization will be automatically

reduced for complex dynamic SQL if optimizer determines that the resources are not necessary.

7 Same as 5 except optimization not reduced for complex dynamic SQL

9 Used to determine whether more comprehensive optimization can generate better access plan for very complex long

running queries using large tables

27

EXPLAIN

EXPLAIN_INSTANCE

EXPLAIN_STATEMENT

EXPLAIN_OPERATOR

EXPLAIN_STREAM

EXPLAIN_OBJECT

EXPLAIN_ARGUMENTEXPLAIN_PREDICATE

Oracle

DB2

PLAN_TABLE

28

Clustering/Scalability: Oracle RAC

Application

server 1

Application

server 2

Application

server 3

Node 1

Instance 1

Node 1 Node 1

Instance 2 Instance 3

RAC

Database

29

Clustering/Scalability: DB2 Purescale

GBP

Group Lock

Manager

Member 1

PRODDB1

CatalogDBCONFIG

Log

Catalog

Log

DBCONFIGPRODDB2

BPs

BPs

Member 2

PRODDB3

CatalogDBCONFIG

Log

Catalog

Log

DBCONFIGPRODDB4

BPs

BPs

DATA

30

Monitoring

• Performance Snapshots - V$– Instance/Database

– Memory

– Disk

– User/Session

– Contention

• AWR (Statspack)– Collects Stats over time

– Similar to DB2 Snapshot

• TKPROF– Formats SQL trace data from applications

• Snapshot Monitor– Show status of database counters at

instant in time

– Buff, Lock, Sort, Stmt, Tbl, UOW

• Event Monitor– Status after the event

• Databases

• Tablespaces

• Connections

• Tables

• Statements

• Transactions

• Deadlocks

• Administrative Views and Table Procedures

DB2Oracle

31

Utilities

• RMAN

• IMPORT

• EXPORT

• SQL*LOADER

• ANALYZE

• DB_VERIFY

• BACKUP

• IMPORT

• EXPORT

• LOAD

• RUNSTATS

• RESTORE

• REORG

• REORGCHK

Oracle DB2

32

Backup/Recovery

33

Backups

Oracle• Database

– Cold

– Hot

• Tablespace

• Components

– Database Backup

– REDO Log

– ARCHIVED REDO logs

– UNDO Records

– Control File

DB2

• Database

– Online

– Offline

• Tablespace

• Components

– Backup Image

– Incremental Copy

– Backup History File

– Active Logs

– Archive Logs

• HADR

– High Availability Disaster Recovery

• Primary/Standby Databases

34

Recovery Info

• Control File

• Database name

• Data file location

• Redo log file location

• Tablespace names

• Current log sequence number

• Checkpoint information

• Log history

• Backup information

• RMAN

– - Recovery Catalog

Recovery History File• Updated:

– Backup of DB/TS

– Restore/Roll Forward of DB/TS

– Drop/Load/Reorg/Stats of a table

– Quiesce/Alter TS

• Contains– Part of DB which was copied

– When DB was copied

– Location of the copy

– Time of last restore

– DDL of tables

Oracle DB2

35

• Redo Logs apply to Instance– NoArchive Mode

• Redo logs overwritten

– Archive Mode

• Recover DB, TS, DF, block

• 3 Redo log states

– Active

– Inactive

– Archived

• Rollback Segments– Exist until data committed

• Defined at database– Circular

• No roll-forward recovery

– Archival• Fully recoverable

• Similar to OS/390

• 3 log files

– Active

– Online Archived

– Offline Archived

• On Demand Archiving

– Close and archive an active log at any time

• Dual Logging

ORACLE DB2

Logging

36

Circular Logging

• Non-recoverable databases

• Log files are reused

• Uses active logs only– Secondary used for overflow

• Roll-forward recovery not

possible

• Default method for new DB’s

S

E

C

O

N

D

A

R

Y

1Primary

1

2“n”

3

“n”

37

Archival Logging

• Log files not reused

• Roll Forward Recovery

Online Archival -

Contains information

for committed and

externalized transactions.

Stored in the active log

subdirectory

12

13

14

15

16

Active –

Contains information

For non-committed or

Non-externalized

Transactions.

Offline Archival

Files moved from active

Log subdirectory.

Usually offline media

38

Recovery Möglichkeiten

• Instance Recovery– RAC only

– Uses Redo logs to recover from

System/Instance failures

• Crash

– Uses online REDO logs

– Recovers data files

• Disaster

• Media Recovery

• Crash– Uses logs to recover from power

interrupts or application ABENDS

• Roll-Forward– Image copy plus log apply

– LOCAL TIME

• Version– Image copy

• HADR

Oracle DB2

39

Datenreorganisation

• OEM Reorg Wizard

– Tables

– Tablespace

– Indexes

– Repair migrated rows

• Online Redefinition Package – Enterprise Edition only

– Online reorg

• REORG– Table

– Index

• REORGCHK– Determines when Reorg is

required

• Online

Oracle DB2

40

Daten laden

• SQL*Loader Utility

– Insert/Append/Replace/Truncate

– Direct=True|False

• By-pass SGA build data block

• No Triggers

• No RI

– Parallel=True|False

• Multiple load files

• Drop all Indexes

– Recoverable/Unrecoverable

• Load– Locks single table in TS

– Insert/Replace

– RUNSTATS

– Good for large amounts of data

– READ ACCESS for rows not being loaded Load directly from a SQL query

• Import– Can dynamically create table

– Insert process

• Update

• Replace

– Good for small amounts of data

Oracle DB2

41

ORACLE COMPATIBILITY FEATURES

42

Einstellung für Oracle Compatibility Features

• DB2 Compatibility Vector– New registry value

• Enables Oracle compatibility

– Controls which compatibility features to turn on

– db2set DB2_COMPATIBILITY_VECTOR=ORA

• Activates all features.

43

Compatibility Features

• Oracle data dictionary compatible views

– ALL_*

– DBA_*

– USER_*

• CLPPlus

– SQL*Plus compatible command line processor

44

Modules

• New DB2 Object– Groups object definitions together for an application

• Functions

• Procedures

• TYPE

• VARIABLE

• Same as Oracle PL/SQL Packages

45

Application Enablement

• Native PL/SQL support– No SQL translation required

– PL/SQL compiler

– PL/SQL debugger

– PL/SQL Object support

• After each row triggers

• Anonymous Blocks

• Before each row triggers

• PL/SQL packages

• Procedures

46

Application Enablement

PackageDBMS_ALERT Allows sessions to semaphore

DBMS_JOB DB2 task scheduler API

DBMS_LOB Oracle LOB API

DBMS_OUTPUTBasic reporting

DBMS_PIPE Allows sessions to send data back and forth

DBMS_SQL Dynamic SQL API

DBMS_UTILITY Misc. application procedures

UTL_DIR Maintains directory aliases used w/UTL_FILE

UTL_FILE Allows working with files on DB2 server

UTL_MAIL Send Email from SQL

Common Packages Provided by DB2

47

Neue DB2 Datentypen

Oracle• BFILE

• BLOB

• CHAR(n)

• CLOB

• DATE

• LONG

• LONG RAW

• NCHAR(n)

• NCLOB

• NUMBER(p,s)

• NVARCHAR2(n)

• RAW(n)

• ROWID

• VARCHAR2(n)

DB2 • BOOLEAN

• INDEX BY

• NUMBER

• Oracle DATE

• Ref Cursor type

• ROW TYPE

• TIMESTAMP(n)

• VARCHAR2

• VARRAY

48

Zusammenfassung

Um erfolgreich ein Cross-Pattform DBA zu sein:

• Wissen was das Prinzip einer relationalen Datenbank ist

• Unterschiede und Besonderheiten anderer RDBMS kennen

• Gleiche Tools können hier unterstützen

• Mit DB2 LUW Version 9.7 ist es einfach von Oracle nach DB2 zu wechseln

© 2010 Quest Software, Inc. ALL RIGHTS RESERVED

Danke für Ihre Aufmerksamkeit