Bruce Black wrote: >> >> >> What about the (unlikely) case where someone writes a VB data set to >> DASD and uses the wrong data length? Or would SAM catch the error >> before you saw it? >> > With SAM I don't believe a bad length is possible. QSAM contructs the > blocks from the records provided and controls the BDW and the write > length. BSAM I believe uses the BDW to determine the write length. So > in either case, the record length in the disk count field will match the > BDW length (short of a bug in SAM, of course). > With EXCP, you can of course write anything you like, so you can create > the error. I am not sure what SAM would do on reading >
I agree about the WRITE. With READ if the BDW indicates a length larger than DCBBLKSI the a WRONG LENGTH RECORD error condition is raised. If the BDW length does not exceed DCBBLKSI then the residual count is set to be consistent with the BDW length. My experiments were some years ago, and I do not recall if all of the block's bytes are loaded into the READ buffer when the BDW length is less than the actual block length. This was all done with BSAM, probably in SP4 days. Cheers, Greg P. ---------------------------------------------------------------------- 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
