Introduction to the new mainfame

transcript

Chapter 12: Databases

Introduction to the new mainframe

ObjectivesIn this chapter, you will learn:

• DB2 concepts• The DB2 system structure• DB2 for z/OS architecture• How to invoke SQL on z/OS• Application programming with DB2• Managing DB2• IMS-DB

Key terms in this chapter• unit of work• DBMS• SPUFI• SQLJ• SYSADM• EXPLAIN• view• modified source

DB2 Concepts: Data Structures

VSAMLDS

Storage group

Data base

Table Space

Index Space

Schema structures

• User-defined Data Type (UDT)• User-defined Function (UDF)• Triggers• Large Object (LOB)• Stored Procedure

System Structure

Catalog and Directory: stores ALL DB2 informationBuffer PoolActive and Archive LogsBootstrap data set (BSDS)

DB2 for z/OS ArchitectureDB2 Address Spaces

• System Service address space (SSAS)• Database Service address space (DBAS)• Internal Resource Lock Manager (IRLM)

DB2 Attachment Facilities• CICS• IMS• TSO

Invoke SQL on z/OS: SPUFI

Select option 1 to enter SPUFI

First you need to create the output file (if not existing)

Invoke SQL on z/OS: SPUFI (continued)

Enter the input and output dataset, if they are not yet in place.Change the member of the PDS, if you want to enter a new SQLDefaults are set to NO from YES.

Enter the SQL statement you want to execute. Press F3 to return to the previous screen (to execute the SQL).

When you get back to this screen, the “edit input” is put to “*”.Press ENTER to execute the SQL and to see the output.

F8 brings the rest of the results on your screen

Application Programming: the flow

SourceSourceProgramProgram

Precompile

IncludeIncludeMemberMember

Compile

Linkedit

ModifiedSource

Object Module

Load Module

Package

DCLGEN

Get the access path: EXPLAIN

EXPLAIN ALL SET QUERYNO = 1SELECT EMPNO, LASTNAME

FROM EMPWHERE LASTNAME = 'MILLER';

-The query is NOT executed-The access path is placed in userid.PLAN_TABLE, if it exists

Other development options

• ODBC• JAVA• SQLJ• JDBC• XML• XML Column Access• XML Collection Access

Managing DB2: System Administration

InstallationSystem Object ManagementSystem and Disaster RecoveryMonitoring System Performance

Managing DB2: Database Administration

Creation and management of DB2 objectsExecution of utilities:

• Data Organization• Backup and recovery• Data Consistency

Commands

Functions of the IMS DM

A DBMS provides:• A single copy of data for access by multiple users • Maintenance of integrity across all updates• Minimization of HW and OS access method

dependencies• Reduction of data redundancy

Implementation of IMS Databases

Depending on user requirementsTechnologies :

• IMS DB or DL/I or DL1 or Full Function Database

• IMS DEDB or Data Entry DB or Fast Path Database

• IMS Main storage database (MSDB)

• IBM DB2

Database Recovery Control (DBRC)

Structure of IMS DB Subsystem

System Address SpaceApplication Region Address Space

Up to 99 in total

DLISeparateAddressSpace

DBRCRegion

MPP IFP BMP

ApplicationProgram

Full Function DBs RECONs

DependentRegion

AddressSpace

IMS System

IMS Libraries

IMS Message Queues

Fast Patch DBs

ControlRegion

AddressSpace

Network

JavaMessage

Processing

JavaBatch

ProcessingApplicationProgram

ApplicationProgram

Databases used by IMS: Database basics

Access pathsNormalization within IMS

• Unique entities• One occurrence only• No many-to-many relationships

Databases used by IMS: DB ModelSequence to access the segments

ROOT(1)

Segment A2(8)

Segment A1(2)

Segment D3(9)

Segment D2(4)

Segment E3(7)

Segment D1(3)

Segment E2(6)

Segment E1(5)

Segment B2(14)

Segment B1(10)

Segment G2(12)

Segment H1(13)

Segment G1(11)

Databases used by IMS: DB model

Additional access paths to segments• Logical relationships• Secondary indices

Application programming overview

Program is subroutine of IMS region controller• Needs a program specification block (PSB)• Uses services:

• Send/receive message from terminals• Access db• Issue IMS commands• Issue IMS service calls

example: Checkpoint calls, Sync call

Program Structure

Segments Segments to/from to/from

databasesdatabases

DLI modules

Call infoCall infofrom DLIfrom DLI

PCB-Mask

IO AREA

Application Program

PROGRAM ENTRYDEFINE PCB AREASGET INPUT RECORDS FROM INPUT FILECALLS TO DL/I DB FUNCTIONS

RETRIEVEINSERTREPLACEDELETE

CHECK STATUS CODESPUT OUTPUT RECORDSTERMINATION

IMS and the World Wide WebMessage flow in IMS transactions

3270 Terminal

VTAM IMS MPP

8,9 7 6

IMS and the World Wide WebMessage flow between Web browser and Web server

Web Browser

WebServer

CGIProgram

8,9 7 6

TCP/IP TCP/IP

IMS and the World Wide WebMessage flow IMS transaction and Web server CGI programs

3270 Terminal

VTAM IMS MPP

8,9 7 6

Web Browser

WebServer

CGIProgram

8,9 7 6

TCP/IP TCP/IP

Program to ProgramCommunications

SummaryIn this chapter, you learned:

• Some DB2 concepts• The DB2 system structure• DB2 for z/OS architecture• How to invoke SQL on z/OS• Application programming with DB2• Managing DB2• IMS-DB

Introduction to the new mainfame

Database Exercises

DB2 Interactive

Default panel 1

Default panel 2

DCLGEN

Do the exercise• Do the DCLGEN• Execute the SQL (change it if you want)• Change the program• Execute the job

Execute from TSO Allocate your datasets first (1)Change your parameters and press enter (2)

Execute from TSO (continued): results

Introduction to the new mainfame

Documents