Informix and block I/O

Path: emory!ogicse!cvedc!mcspdx!jims From: jims@pdx.csd.mot.com (Jim Santmyer) Newsgroups: comp.databases.informix Keywords: Help!!! Help!!! Help!!! Message-ID: <1018@pdxvme.pdx.csd.mot.com> Date: 4 Nov 91 02:12:40 GMT Organization: Motorola CSD, Beaverton, OR Posted: Sun Nov 3 18:12:40 1991 HELP! I am working on a project where an informix database is located at a central site running on a UNIX system V CPU and users are located at remote sites using dumb ascii terminals over an X.25 network. We are experiencing a severe network performance problem. Our communications hardware vendor tells us the reason for the performance problem is that we are doing "Host echo" (the informix 4gl application does the echoing). He continued to say that if the terminal could be setup in block mode and do it's own echoing or if the local X.25 hardware is configured to do echoing, we would eliminate at least 50% of the network traffic, increasing performance significantly. (i.e. when doing "host echo" every key stroke creates two network packets, one to send the keystroke to the host and the second for the host to echo it back to the terminal. If we can eliminate the need to do host echo and perform local echo each keystroke creates at most one packet, thus cutting network traffic by 50%, and if we can send a field of data to the host at one time instead of each keystroke we cut down on network packet over head even more.) I have been working on ways to perform local echoing and have been succussful at getting it to work except for two informix problems I hope some one can help me with. I am not a data base programmer, in fact this is my first experience with any sort of data base application, so if these sound like simple or unsolvable problems I apologize. Problem 1: In order for local echo to work all informix field labels must be "write-protected" so the user can not type over them. This requires that each field label be proceded by an ESC) and followed by ESC( (these are the escape sequences used to delimit write protect fields on our terminal). In addition write protect mode is turned on by sending an ESC& to the terminal. The easist way to do this appears to be to set these escape sequences up in the termcap file, create the screens using the informix forms generator and send these escape sequences to the terminal as a field attribute, just as would be done to highlight a field label in bold or underline. But I have not been able to get this to work (all I get is garabage on the screen). I have been told that I need to use Informix 4gl to create variable data fields that are filed in from the data base when the screen is drawn. The data base entries would have the escape sequences in them to write protect the fields. But, not knowing Informix this seems like a lot of work, so I would perfer to use the termcap file and field attributes if possible. Problem 2: Informix is echoing each character it receives, so when I configure the local hardware (either the terminal or communications hardware) for local echoing each charater is displayed twice on the terminal screen. Is there any way to turn echoing off in Informix? Any help I can get will be greatly appreciated.