Ah. Thanks (again). Doesn't IEBCOPY use the binder under the covers for load modules, or am I thinking of a different problem?
Charles -----Original Message----- From: IBM Mainframe Discussion List [mailto:IBM-MAIN@bama.ua.edu] On Behalf Of Robert A. Rosenberg Sent: Monday, January 24, 2011 1:25 PM To: IBM-MAIN@bama.ua.edu Subject: Re: Long-running jobs, PDS, and DISP=SHR At 09:43 -0800 on 01/24/2011, Charles Mills wrote about Re: Long-running jobs, PDS, and DISP=SHR: >A problem that no one has pointed out is that if a job is using a STEPLIB >DISP=SHR and we say it is okay to update that library DISP=SHR, then how can >we be sure that TWO people won't try to update it at the same time DISP=SHR? > >The problem -- and I'm being analytical and technical here, not critical of >IBM or MVS -- is that the PDS ENQ mechanism is not granular enough. A >thorough solution would require the ability to be OLD on a member but SHR on >the directory, and also provide for an "any number can read but only one can >write" sort of DISP. (SHR being "any number can read but none can write.") > >Charles As I noted, if the updating is being done by Linkedit/Binder (as opposed to IEBCOPY) there is an ENQ lock (QNAME=SYSIEWL [I think] with RNAME=the DSN) that prevents other Linkedit/Binder instances from accessing the PDS/PDSE while it is being updated. This does not, however, impact anyone who is using the library as a JOBLIB/STEPLIB (or as a LINKLIST dataset). ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to lists...@bama.ua.edu with the message: GET IBM-MAIN INFO Search the archives at http://bama.ua.edu/archives/ibm-main.html
