As Brian mentioned, DB2 uses the XTIOT, which is stored in non-contiguous storage, above the 16 MEG line. However, in z/OS 1.4 and before, the DSAB chain, which is used to manage all allocations, was still below the 16 MEG line, which limited the the total number of allocations available. However, in z/OS 1.5, the DSAB chain now resides above the line, relaxing these limits. Wayne Driscoll [EMAIL PROTECTED]
"Brian Peterson" <[EMAIL PROTECTED]> wrote in message news:<[EMAIL PROTECTED]>... > You wrote "this is not a DB2 question". > > The number of open data sets per jobstep is controlled by the size of the > TIOT table. You control the size of the TIOT using SYS1.PARMLIB(ALLOCxx) > entry TIOT. The default TIOT size is 32K which provides for 1635 maximum > data sets per jobstep. > > DB2 uses the XTIOT. This is why DB2 is not limited to the TIOT size limits > mentioned above. > > Brian > > On Wed, 4 Aug 2004 10:19:40 -0500, Mark Ediger <[EMAIL PROTECTED]> > wrote: > > >Greetings, > > > >In the DB2 for z/OS V8 (this is not a DB2 question) Installation > >Manual, there is the following statement: > > > >|The maximum number of > >| concurrently open data sets is typically 25 000 to 32 000 if you are > >using > >| z/OS V1R4 or earlier. If you are using z/OS V1R5 or later, the > >maximum > >| number of concurrently open data sets is typically 100 000. > > > >Do any of you know if this limit is set by parameter or is implicit in > >the release? If the latter, then is this the same as the "maximum > >generated ddnames limit reached" message that is specified in the > >message IKJ56227I which seems to be 32,767? > >I can not find any mention of this in 1.5 documentation or announcement > >letter. I do know its there because there is a comment in the IHAQDB > >macro which states "open data set limit relief". > >Any information you have will be helpfull. > >Thanks > >Mark Ediger > >Acxiom > > > > ---------------------------------------------------------------------- > 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 ---------------------------------------------------------------------- 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
