On 18 May 2007 13:30:32 -0700, in bit.listserv.ibm-main you wrote: >Picking up on something Paul G. said in another thread, I realized I have >never known *why* the system issues JOB scope ENQ's on DSN's. > >I do realize that it is most probably to avoid an ENQ "deadly embrace" >somewhere along the line, but for the life of me (well, and maybe because >it's Friday) I can't think why a DSN ENQ would be JOB scope instead of STEP >scope. At least not by default, anyway. > >I suppose if you create a dataset in step A and then use it DISP=SHR in step >B (or F or Z, way down the line), if it were not JOB scope ENQueued some >other job could come in-between your create and use steps and delete it on >you, or update it in some clever but unscrupulous way, but I really can't >think of a scenario that means JOB scope ENQ's are required. > >TIA for curing my ignorance on this subject.
AS I understand it, The ENQ for a data set is from start of job until the last using step. If the ENQ is exclusive for the first step and shared for the second, it will be changed by the initiator/terminator between steps. If no further step requires the data set the ENQ is dropped. JES3 may do some additional things. Since the Job is the unit of work that requires the data set it should have it for as long as it needs it. FREE=CLOSE also influences things. > >Peter ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to [EMAIL PROTECTED] with the message: GET IBM-MAIN INFO Search the archives at http://bama.ua.edu/archives/ibm-main.html
