Binyamin, thanks a lot!! One book on my hand has a chapter about channel programming and i'll take a look at it to get more hints.
On 5/4/07, Binyamin Dissen <[EMAIL PROTECTED]> wrote:
On Fri, 4 May 2007 22:11:08 +0800 Johnny Luo <[EMAIL PROTECTED] > wrote: :>The first is what actually determines the physical blocksize? You told me :>BLKSIZE parm is a maxmimum value for QSAM. So I guess if I write 105 records :>to a data set with BLKSIZE=20, I'll get five 20-byte physical blocks and one :>5-byte block(if no padding occurred.) Right? For QSAM, the physical blocksize at PUT is based on the DCB value, except that blocks are not padded - if all the records fit within less than the blocksize a short block will be written. GET expects a physical block to contain up to the blocksize value and will report an error (via S001 or SYNAD) if the physical block is larger. :>The second is concerning the minimal physical unit a program can process on :>zos. I know acess method macros like QSAM are still at the high level. From :>what you told me, I guess the minimal unit QSAM can process is one physical :>block. It cannot read, say, half physical block. And that's why my program :>abends: the buffer size cannot hold a physical block. None of the high level access methods support reading a partial block. It will always request some number of blocks from the IO system. Your program can choose to recover from the error. --
Best Regards, Johnny Luo ---------------------------------------------------------------------- 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
