运行ibm mainframe期末复习

I . z/os

1. data set name, temporarydataset, symbol ic variable

1) Data setsarethefi lesthatcontain programsanddata

2) A data set namecan be one name segment,or a series of joined name segments.Each name segment represents a level of qual ification. For example, the data setname STU237.SEU.JCL is composed of three name segments. The first namesegment on the left is cal led the high-level qual ifier (HLQ), and the last namesegmentonthe right isthe lowest level qual ifier (LLQ).

3) Segments or qual ifiers are l imited to eight characters, the first of which must bealphabetic (Ato Z)or special character (#,@, $).The remaining seven charactersareeitheralphabetic (a-z), numeric(0-9), special,or a hyphen (-).Name segmentsare separated bya period (.).

4) Including al l name segments and periods, the length of the data set name mustnot exceed 44 characters

5) injcl :

&Toidentify a symbolic parameter.ex.&LIB

&&To identify a temporary data setname.ex.&&TEMP1

6) TemporaryData Sets:The namestarts with two ampersands(&&)fol lowed by 1 to8characters.ex.//step1 DD dsn=&&temp01

2. IBM uti l ityprogram: IEFBR14, IEBGENER, IEBCOPY, IDCAMS

1) Utilities are pre-written programsthatperform commonlyneeded functions.Useuti l ityprogramstoassistyou inorganizingand maintaining data.Data Set Uti l ityPrograms:Youcan usedata set uti l ity programsto copy,move,reorganize, change,orcomparedata atthedata set or record level .Data Set Uti l itiesstart with IEBxxxxx

2) IEBCOPY: tocopy, compress,or mergepartitioneddata setsor PDSEs.

IEBGENER:Copy records from asequentialdata set or convert a data setfrom sequential organizationtopartitionedorganization.

IEFBR14:Dummy uti l itya. IEBCOPY(Li brary Copy) Program:

-Copy partitioned data set(PDS). (ISPF3.3 inbatch mode)

-Copy partitioned data set members.

-Compress partitioned data setsin place.

-Make a copyof a partitioned data set.

-Merge partitioned data sets.

-Create a sequentialform of a PDSfor backuportransport.

-Copyand re-blockload modulesb. IEBGENER

Use IEBGENERtocopyone sequentialfi letoanother. (ISPF 3.3in batchmode)

Toprint sequential data setsormembersof partitioned data sets.

Tocreate partitioneddata set membersc. IEFBR14

IEFBR14isa nul lprogram. Itdoesnothing it executesa singlestatement,which specifiesthe end ofprogram.

It’susedasa dummystep,ortoal locate/delete data sets

3) I D CA M S主要用于创建和操作VSA M数据集和目录操作

3. LPAR iswhat?Why use it?

1) Logical PARtition

2) 实际上是指通过虚拟手段一组逻辑上独立的资源可以用来运行一个系统逻辑上可以看成一个独立的计算机。大型机操作系统总是在LPAR模式中运行即使一台大型机只运行一个OS。 LPAR可以运行各种系统不必是z/OS

3) why?a. Logical partitions are, in practice,equivalentto separate mainframes. EachLPARruns its own operating system(OS).b. Reduce number of servers(mainframes).c. Running different OS.d. Running differentversions of OS

4. z/ossubsystem and component: JES,TSO, ISPF,SDSF,RACF

1) RACF(Resource Access Control Faci l ity) is az/OS security subsystem

2) TSO/E(Time Sharing Option/Extensions).

• ISPF(Interactive System Productivity Faci l ity).

• TSO/E and ISPF al low you to log on to the z/OS system,run programs, andmanipulatedatafi les

3) JCL(Job Control Language) is usedtosubmit batchjobtoz/OStoexecute

4) JES(Job Entry Subsystem)receive jobs into the operatingsystem, to schedule themforprocessing“by z/OS,and tocontrol th”eir output processing

5) SDSF: IBM的 系统显示与查询工具 简称SDSF是OS/390的可选产品可以向用户提供大量的信息以协助用户监测、管理以及控制MVS/JES2系统

5. logical record, physical record,why blocking?why a physical record contains manylogical records

1) A record is a fixed number of bytes containingdata and is the basic unit ofinformation used bya program running on z/OS

2) A logical record is a unit of information(for example, a customer, an account,apayrol l employee, and so on). It is thesmal lest amount of data to beprocessed,and it is composed of fields that containinformation recognized bytheprocessingappl ication program

3) Logical records are grouped within physical records named blocks. BLKSIZEindicatesthe lengthof those blocks

4) block为了节省ioand save space

6. z/osmasterand usercatalog,what kindof information saved incatalog?

1) A catalog records the location of fi les.When a data set is cataloged, it can bereferred to by name without the userneeding to specify where the data setisstored

2) To find a data set that you have requested,z/OS must know three piecesofinformation:

1.Data setname.

2.Volume name.

3.Unit (thevolumedevicetype, suchasa3390 diskor3590tape)

•A catalog is used to store and retrieve theUNITand VOLUME information of adataset.

3) A typical z/OS system uses one master catalog and numerous usercatalogscon nected to ita. The master catalog usual ly stores only thesystem data sets and name of theusercatalogs.b. The usercatalog stores userdata sets.c. Thiswi l l makemigration(迁移)mucheasier

7. characteristicof sequential data set and partitioned data set,directoryblock

1) Asequential data set(PS) consists ofone or more recordsthat are stored inphysicalorder and processed in sequence. New records are appendedto the end of thedata set.

2) A partitioned data set(PDS) is a col lection of sequential datasets, cal ledmembers.Eachmember is l ike a sequential data set and hasa simple name,whichcan be upto eight characterslong

3) directoryblockstoresthe entryof each members

8. JCLcoding rules, howtocontinue tonext l ine

1) JCL is used to tel l the system what programs to execute,what datasetstheseprogramswi l l use,what isthedisposition of data setswhen theprogram executionends.

2) Format of JCLStatements(noperiod)a. Identifier field: Indicates to the systemthat a statement is a JCL statementratherthandata.Columns1and2of al l JCLstatementscontain//.b. Name field:The name is1 through 8 alphanumeric or nationalcharacters($,#,

@).can’tappearatColumns1and2c. at least one space between name field and operation fieldd. Operation field:The operation fieldspecifiesthe type of JCL statement.e. at least one space between operation field and parameter fieldf. Parameter,or operand field:Containsparameters separated bycommas.

3) When the total length of the fields on a controlstatement exceeds 71 columns,continuethefields onto the next line.a. Interrupt the field after a complete parameter or subparameter, including thecommathatfollows it,atorbeforecolumn 71.b. Code // in columns 1 and 2 and a blank character in column 3 of thefollowingstatement.c. Continue the interrupted parameter or field beginning in anycolumn from 4through 16.ContinuingJCL Statements

9. basicJCLstatement—JOB&EXECcard

1) You enter a program into theoperating system to execute as a job step.Ajob stepisidentified byan EXECstatement.

2) Ajob is a collection of related job steps.Ajobis identified by a JOB statement

3) JOB-Providesa name(jobname)tothesystemforthisbatchjob.a. //jobname JOB parameters, parametersMarks the beginningof a job,assignsa nametothejob

1. Eachjobname should be unique.(can havethesamejobname)

2. Thejobnamemust beginincolumn 3.

3. jobname is 1 through 8 alphanumeric (A-Z,0-9) or national ($, #,@)characters.

4. Thefirst character must be alphabetic or national ($,#,@).

5. Thejobname must befol lowed byat least one blank.

b. Usejust onlyone,toseparate parameters

1. NOTIFY=Sends notification of job completionto a particular user, such asthesubmitterofthejob.

2. CLASS=Directsa JCLstatementtoexecute on a particular input queue.

3. MSGCLASS=Directsjoboutputtoa particular output queue.

4. MSGLEVEL=Controlsthe number of systemmessagesto be received.

4) EXEC-Providesthe name of a program toexecute. Each EXECstatementwithin thesame job is ajob step.a. The EXEC statementmarks the beginning of each job step in ajob or aprocedureb. //stepname EXEC parameters,parametersc. A stepname is optional .When a stepnameis needed, it must be unique withinthejob.

1. The stepname is 1 through 8 alphanumeric or national characters ($, #,

@).

2. Thefirst character must be alphabetic or national character ($,#,@).

3. The stepname must befol lowed byat least one blank.d. An EXECstatement must contain oneofthe positional parameters:PGM,PROC,or procedure name.

1. Use the PGM parameter to name the program that the system istoexecute.a. Exampleof the PGM Parameter:

//STU278A JOB CLASS=A,…

//STEP1 EXEC PGM=LAB1

2. Use the PROC parameter to specifythatthe system isto cal l and executeacataloged or in-stream procedurea. Examplesof the PROCParameter:

1.//STEP1 EXECPROC=MYPROC

2.//STEP2 EXECMYPROC

3. JCL procedure(PROC)a. Some programs and tasks require a larger amount of JCL than a usercan easi lyenter. JCL for these functions can be kept in procedurel ibraries. Such a procedure is sometimes known asa cataloged

5) DD-The Data Definition provides inputsandoutputstothe execution program onthe EXECstatement. This statement l inks a data set orother I/O device to addnamecodedintheprogram

10. JCLspaceand dispof“DD”statement

1) //ddname DD parameters,parametersa. Theddname specifiesthe nameof the DDstatement.

1. 1through8alphanumeric ornational ($,#,@)characters.

2. Thefirst character must be alphabetic or national ($,#,@)b. Temporary Data Sets:The name startswith twoampersands (&&)fol lowed by 1to8characters.ex.//step1 DD dsn=&&temp01

2) DISP=Data setdisposition(安排), suchaswhetherthe data set needsto becreatedoralreadyexists,andwhetherthe data setcan beshared bymorethan one joba. NEW-Anewdata set istobecreated inthisstep.b. OLD-The data set exists before this step and thatthis step requires exclusive

(unshared)use of thedata set.c. SHR-The data set exists beforethis stepandthatotherjobs can shareit, that is,

use itatthesametime.d.MOD- Indicatesone of thefol lowing:

1. The data set exists and records are to be added to the end of it.The dataset must be sequential .

2. A new data set is to be created. In either case,MOD specifies exclusive

(unshared)use of the data sete. DELETE-thedata set istobe deleted if thisstepterminatesnormal ly.f. KEEP-thedataset istobe kepton thevolumeif this stepterminatesnormal ly.g. PASS - the data set is to be passed for use bya subsequent step in the samejob.h. CATLG- if the stepterminates normal ly, thesystem isto place an entrypointingtothe dataset inthesystem or usercatalog.i . UNCATLG- if the stepterminatesnormal ly, thesystem isto delete(1)the entrypointingtothedata set inthesystem orusercatalog.

3) SPACE= al locate storage space for new data sets on DASD.The SPACE parameterhas no meaning for tape volumes. Total space wi l l be al located: 1primaryextentand upto 15secondaryextents.a. Ex.Al locate a PS data set:

//SPACE=(TRK,(5,2))

*Maximum al location 35tracks(15*2+5=35), no directory specified for PS.b. Ex.Al locate a POdata set:

//SPACE=(CYL,(2,1,5))

*Maximumal location 17cyl inders(15*1+2=17),5 isthe directory block.I I . COBOL

1. COBOL syntax

1) COBOL program Layout(Each sentence endswith a period)a. COBOL programfol lowscertain rules:

Column 1-6: reserved for l ine numbering.

Column 7: continuation or indicator area.An * in column 7 indicates acomment l ine.

Column8-11:area A.

Column 12-72:area B.

Column 73-80:program identification.b. Eachsentenceendswitha period.

2) COBOL programsare broken intofourdivisions.a. IDentification Division.b. Environment Division.c. Data Division.d. Procedure Division.e. Each division divided intoSections,eachSection divided into Paragraphsf. divisions->Sections->Paragraphs

3) IDENTIFICATION DIVISION identifies theprogram name to the compi ler.Must bethefirst division in every COBOL sourceprogram.a. PROGRAM-ID section

b. DATA-WRITTEN sectionc. AUTHOR section

4) ENVIRONMENT DIVISIONa. Configuration Section(rarely used.)b. Input-Output Section

1. I-O Control paragraphs(rarely used.)

2. File-Control paragraphs(always used)describesthe use of data fi les in the

COBOL program.

5) DATA DIVISION Describes the data used by the program. The DataDivision isbroken intothe fol lowing sections:a. FILE SECTION. -Defines the fi les being used bythe COBOL program and givesthe record-namesassociated with that fi le. (work with File-Controlparagraphsby FD statement )b.WORKING-STORAGE SECTION.Describesdata records that are not part of datafi les but aredeveloped and processed bya program.(self use)c. Linkage Section.–passes data between programs(cal l subprogram)

6) PROCEDURE DIVISIONis where the program’sprocessing occurs. It’s made up ofSections and Paragraphs.But sections usual ly not used.a. It mustcontainat leastone paragraph.b. The paragraph name beginsinarea A.c. Programming statements,orsentences beginin area B.

(其中input-fi le是cobol data要在COBOL中定义 indata是外部fi le要在jcl中定义)

7) WithCOBOL, al ldata,paragraph,andsectionnamesmay be upto30characters

2. val idCOBOL data name