The CMS EDF file system is a very lightweight file system that has survived 40+ years with this restriction. (EDF was introduced in SEPP or BSEPP, I think.)
Back then VSAM was available to solve more complex data management issues. Now, you re-platform. Regards, Alan Altmark IBM > On Sep 12, 2020, at 12:27 PM, Paul Gilmartin <paulgboul...@aim.com> wrote: > > On 2020-09-12, at 06:18:25, Rob van der Heij wrote: >> >>> On Sat, 12 Sep 2020 at 01:18, Stanislawski, Shawn (National VM Capability) < >>> shaw...@dxc.com> wrote: >>> >>> Would be preferable to avoid truncation of a longer new record when >>> dealing with recfm=VARIABLE. >>> But at this point, it sounds as if there is not an elegant resource-light >>> method for so doing? >>> >> >> Would you mind to mark the original as "deleted" and append the longer >> record to the RECFM V file maybe? But I guess you were going index by >> record number rather than a key. >> > I understand that MDFS indexes blocks (not records) in a tree. > I was disappointed that does not support "elegant resource-light" > insertion, deletion, and replacement of records. (Yes, that > would require splitting blocks when records are inserted, marking > parts of blocks as unused, and balancing the tree for performance.) > > SFS is merely secret. > > -- gil >
