z/OS V1R6.0 DFSMS Access Method Services for Catalogs

JCL DD StatementsWhen you use a JCL DD statement to identify a data set, include this on the DDstatement:v User data set namev Catalog name of the BCSv VVDS namev Unit and volume serial numbers, if the data set is not catalogedv Dispositionv AMP='AMORG' is required for VVDSsJCL DD Statement for a VSAM Data SetYou can allocate VSAM data sets directly with the access method servicesALLOCATE command. The following DD statements demonstrate two additionalmethods of describing and allocating a VSAM data set:vvFor allocating and creating a new data set://ddname DD DSNAME=dsname,DISP=(NEW,CATLG),RECORG=KS,// SPACE=(TRK,10,10),STORCLAS=xxxxxFor allocating an existing data set://ddname DD DSNAME=dsname,DISP=OLDAccess method services does not provide protection for data sets in a sharedenvironment. Therefore, you should use DISP=OLD on the DD statement for anydata set that can be accessed improperly in a shared environment.JCL DD Statement for a VolumeTo identify and allocate a volume, include:v Volume serial numberv Dispositionv UnitThis DD statement identifies and allocates volume VSER01://VOLDD DD VOL=SER=VSER01,UNIT=3380,DISP=OLDFor information on concatenated DD statements, see the FILE parameterdescriptions in Chapter 3, “Functional Command Syntax.” Examples usingconcatenated DD statements follow the description of the REPRO command thatbegins on Chapter 30, “REPRO,” on page 305. For additional information about thevarious types of concatenated DD statements, see the section on special DDstatements in z/OS MVS JCL Reference.JCL DD Statement for a Non-VSAM Data SetYou can allocate non-VSAM data sets with the access method services ALLOCATEcommand. See the DD statements in the examples that follow the descriptions ofthe BLDINDEX, EXPORT, IMPORT, REPRO, and PRINT commands for additionalmethods of describing and allocating non-VSAM data sets.JCL DD Statement for a Snap DumpIf access method services encounters a condition that requires it to abnormally enda job, it takes a snap dump of virtual storage. You must write an AMSDUMP DDstatement to get the snap dump; that is,//AMSDUMP DD SYSOUT=AIf you do not supply an AMSDUMP DD statement and access method servicesencounters a condition requiring the job to abnormally end, it produces only anabbreviated dump.Chapter 1. Using Access Method Services 3