db2 components & basics 1

8/6/2019 Db2 Components & Basics 1

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Copyright IBM Corporation 2007

Unit Objectives

After completing this unit, you should be able to describe the maincomponents of a DB2 environment and the roles they play:

Users

Data

Programs (Static, Dynamic)

System


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What Is DB2 for z/OS?

Relational Data Base Management System (RDBMS)

Data base consists of tablesSimple conceptsDynamic relationships

Structured query language (SQL)

High levelData Manipulation Language (DML)Data Definition Language (DDL)Data Control Language (DCL)

User specifies WHAT not HOW

RDBMS facilitiesIntegrityDynamic definition of DB2 objectsActive catalog

Recovery / restartContinuous operationsSecurityInteractive tools


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The Users View

000010 Chris I Haas A00 3978 1965-01-01

000020 Mike L Thomson B01 3476 1973-10-10

000030 Sally A Kwain C01 4738 1975-04-05

000060 Irving F Stern D11 6423 1973-09-14

...

000050 John B Geyer E01 6542 1972-02-02

A00 Spiffy Computer Ser. Div. 000010 ...

B01 Planning 000020

C01 Information Center 000030

D11 Manufacturing System 000060...

D01 Development Center ?

QMF / SPUFI

SELECT LASTNAMEFROM EMPWHERE EMPNO = 000050

Result Data : Geyer


4/18 Copyright IBM Corporation 2007

Another Kind of User

000010 Chris I Haas A00 3978 1965-01-01000020 Mike L Thomson B01 3476 1973-10-10

000030 Sally A Kwain C01 4738 1975-04-05

000060 Irving F Stern D11 6423 1973-09-14

...

000050 John B Geyer E01 6542 1972-02-02


B01 Planning 000020


D11 Manufacturing System 000060

...


EMP NR ? EMP NR ?

000050

LASTNAME :

Geyer

GET ...MOVE ...

SELECT LASTNAMEFROM EMPWHERE EMPNO = :EMPNO



The Static Programs View000010 Chris I Haas A00 3978 1965-01-01

000020 Mike L Thomson B01 3476 1973-10-10

000030 Sally A Kwain C01 4738 1975-04-05

000060 Irving F Stern D11 6423 1973-09-14

...

000050 John B Geyer E01 6542 1972-02-02EMP NR ?

EMP NR ?

000050

LASTNAME :

Geyer

SELECT LASTNAMEFROM EMPWHERE EMPNO = :EMPNO

PUT

GET

MOVE

EXECUTE

PUT


B01 Planning 000020



...


VSAM

SEQUENTIALDATA SET

DL/1



The Dynamic Programs View000010 Chris I Haas A00 3978 1965-01-01

000020 Mike L Thomson B01 3476 1973-10-10

000030 Sally A Kwain C01 4738 1975-04-05

000060 Irving F Stern D11 6423 1973-09-14

...

000050 John B Geyer E01 6542 1972-02-02ENTER SQL:

SELECT ...FROM EMPWHERE ...

Geyer

PUT

GET

EXECUTE

PUT


B01 Planning 000020



...


VSAM

SEQUENTIALDATA SET

DL/1



UPDATE B

Logical Unit of Work

UPDATE A

COMMIT

A 2000 1000 1000 1000

B 3000 3000 4000 4000

UPDATE BUPDATE A

ROLLBACK

A 2000 1000 1000 2000

B 3000 3000 4000 3000

A program transfers $1000 from account A to account B

A Program's Responsibility -A Logical Unit of Work



The Systems View

DB2 receives MANY requestsfrom MANY user programs toaccess potentially the SAME data

Besides USER PROGRAMS,DB2 also receives requests fromUTILITIES

Utility

Trx2

Prog2

TSO

Trx1

CICS

Trxb

Trxa

IMSDB2

Utility

BATCH

Prog1

WebSphereApplicationServer

Appl2

Appl1

DistributedApplications



Utilities

COPY

SEQUENTIALDATASETLOAD

REORG

Work at the OBJECT level

Run in BATCH

Compete with user programs for resources

Specify your requirements usingCONTROL STATEMENTS mostly

IMAGE COPY



DB2s Responsibilities - SECURITY

DB2 must verify whether a request is LEGITIMATE

GRANT SELECTON TABLE T1TO JAN, PIERRE ;

GRANT UPDATE ONTABLE T1 TO JAN ;

Table User Select Update

T1 Jan Y YT1 Pierre Y N

DB2 CATALOG

DB2UPDATET1 SET ...

SELECT ...

FROM T1 Jan

PierreSTOP

OK



Data integrity and concurrency

Prog1 Prog2

.

.

.

UPDATE

COMMIT

SELECTOK

Row

RELEASELOCK

SHAREDLOCK

... WAIT ...

EXCLUSIVELOCK

DB2 must maintain data integrity and alsoprovide maximum concurrency

STOP

1

2

3

4

EMPLOYEE Table

DB2 S t L D t S t



DB2 System Log Data Set

LOG

DATASETX X X

Program

UPDATE

INSERT

COMMIT

DB2

Data Buffer

X

ASYNC

X

DATA

XXX

Log Buffer

before after

SYNC

COPY/RECOVER Utiliti


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COPY/RECOVER Utilities

Log Time

UPDATE UPDATE DELETE

IMAGE COPY

RECOVER

DISKCRASH

COPY

DB2 R ibiliti PERFORMANCE


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DB2s Responsibilities - PERFORMANCE

Program DB2

WHAT

LoadModule

AccessPathEXECUTION

CatalogStatistics

BIND

HOW

Optimizer

DB2 must translate a users or programsSQL request into ACCESS STRATEGIES

DB2 R ibiliti METADATA


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DB2

CATALOG

Data

Definitions

Security

Definitions

Recovery

Information

SystemAdministrator

DatabaseAdministrator

ApplicationProgrammer

S Q L

DB2s Responsibilities - METADATA

DB2 uses a centralized CATALOG and DIRECTORY

DB2 for z/OS Data Sharing


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Improved availability

Huge queries feasible

SYSPLEX hardware requiredSingle shared catalog

z/OS

DB2 DB2 DB2

DB2 SHAREDDASD

DB2

DB2 DB2 DB2

Incremental processing growth

Configuration flexibility

Dynamic workload balancing

DB2 for z/OS Data Sharing

z/OS z/OS

z/OS z/OS

z/OS z/OSz/OS

Roles and Interfaces in DB2


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Roles and Interfaces in DB2

FunctionalDesigner

Programmer

TechnicalDesigner

DatabaseAdministrator

SystemAdministration

SecurityAdministrator

DataAdministrator

CapacityPlanner

z/OSSysprog

CICS/IMSSysprog

TP

Specialist

Operations

Unit Summary


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Unit Summary

Having completed this unit, you should be able to describe the maincomponents of a DB2 environment and the roles they play:

Users

Data

Programs (Static, Dynamic)

System

db2 components & basics 1

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