In a recent thread in ASSEMBLER_LIST, the OP asks if it's possible to append to a PDS(E) member. No, because the architecture of PDS makes this prohibitively difficult. Likewise, concurrent writing to multiple PDS members is prohibited because of that architecture.
But the (undisclosed) architecture of PDSE removes the second restriction. Why not also remove the first? Clearly not all writes to a PDSE occur at end-of-information. Several answers to the "append" question suggested copying to a temporary name, appending, and at the end deleting the original and renaming the temporary, but cautioned of a timing window. It would seem that STOW ,,R closes that widow. Is there any need even to specify a member name before the STOW? And I was pleased to learn that ISPF Library Management Services allow concurrent writing to multiple PDSE members. There's no specific documentation of this. There needn't be; it simply works. But I stumbled on a puzzling restriction: ISPF LMMREP can not create an empty member; it must be preceded by at least one LMPUT, which creates a record. Is there a sound technical reason for this, or is it the whim of a designer who couldn't imagine a use for an empty member, therefore it should be prohibited/ (Dog in the manger?) It's clearly not impossible: IEBGENER with SYSUT1-DUMMY or ISPF Edit readily create empty members. But is specialized processing necessary to achieve this? --- gil ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to [email protected] with the message: INFO IBM-MAIN
