On Mon, Nov 2, 2009 at 5:02 AM, BISHOP, Peter <[email protected]> wrote:
> To John M - yes, I was thinking in "z/OS" terms, where a single open of the > DDNAME is sufficient for all the datasets in that DDNAME. > > To David, Ed and John S - the annoying thing about pipes here is that they > incur extra I/O for the "cat" command, and since these files are very large > (approx 20GB daily) this extra I/O will be very costly, probably excessively > so here. > Looks like I'm out of luck here, more thinking required. What extra I/O do you mean? When "cat" has multiple arguments, it will open one file after the other, read them to end-of-file and write the output to stdout. You can pipe that into your processing. If it's your own application, you could make the application process a list of file names. As far as I know this is similar to how MVS does extents. You would have extra I/O when you had to compose the input file on disk by appending all your input files. But in a lot of cases you can make the program use stdin and take the data from the pipe. Rob ---------------------------------------------------------------------- For LINUX-390 subscribe / signoff / archive access instructions, send email to [email protected] with the message: INFO LINUX-390 or visit http://www.marist.edu/htbin/wlvindex?LINUX-390
