maybe i am the last person in the world to stumble acrss this; if so i fell pretty lame ...
when upgrading to a new release of IDMS (or any mainframe product, for that manner) we re-use the runtime libraries - the dataset names are NOT release dependent - it would be easy to delete/allocate the datasets - EXCEPT - with our globally-distributed workforce, there seems to always be someone logged on with the dataset in their TSO allocate member - we used to have to knowck them off tso to free the allocation on the datasets . UNTIL ...
we stumbled into the following:
/* REXX */
DSNAME = 'your llibrary to be cleaned out'
DSN = STRIP(DSNAME, 'BOTH', '''') /* IN CASE IT'S IN QUOTES */
QUOTE = "'"
QDSN = QUOTE||DSN||QUOTE /* FULLY QUOTED DSN */
"LMINIT DATAID( MYDATAID) DATASET(" QDSN ") ENQ(SHRW)"
"LMOPEN DATAID("MYDATAID") OPTION(OUTPUT)"
"LMMDEL DATAID("MYDATAID") MEMBER(*)"
SAY DSN " IS NOW EMPTY"
its quick and it works!(this can be stacked multiple times for multiple datasets within one execution