Re: HPL Q : For Guru

sanjeev sagar <sanjeevsagar@rocketmail.com> offerred: +Q : How can i use Pipe while doing unload through hpl. + +Informix IDS 7.30 on Sun/Solaris 2.5.1 + +Actually, my table is 22gb, i want to use pipe in +order to compress it on fly b'coz of not enough disk +space. I did following. + +1. Prepare job in hpl by using device pipe array i.e +mknod /tmp/pipename1 p +mknod /tmp/pipename2 p HPL does not want this type of pipe for a pipe device. When it says pipe, it means it wants an executable that will read data. It will for off that executable and then send the data it is unloading to the stdin of that executable. So if compress was the name of the excutable, you'd want to use /path/compress as your entry in the pipe device setup screen. The compress program would have to read it's input from stdin. To use named pipes, you have to set them up as a file device. Not sure how HPL will react to such a device though - isn't there a limit to how much data a named pipe can accomodate at any one time? Your compress program would have to be started, possibly first, and then block on reads from that pipe. It would have to be able to keep up with hpl, i.e. it would have to consume data from the pipe at a rate that will allow hpl to write to the pipe w/o getting an error back. Hope this helps. Dave ** Dave Kosenko <davek@summitdata.com> ** Director of Training Services (732) 469-4070 ** Summit Data Group (an Informix Authorized Education Center) ** Find my advice useful? Let me teach you everything I know about ** Informix. Sign up for OFFICIAL Informix training at SDG. ** For details, see http://www.summitdata.com/training