Big datafiles errors

Started by Emanuel1410, July 25, 2022, 10:08:50 AM

Previous topic - Next topic

Emanuel1410

Hello everyone, i'm migrating my destkop application to inomas but whenever i have to read a large file (for example, 1gb file), my query, or making a report results on crashes or infinite loadings

Thanks!
Emanuel

Mike King

When running in iNomads you need to be aware of browser limitations.  For example if you attempt to load a list box with hundreds of thousands of records the time to transfer this data plus its browser formatting may exceed the memory available on the workstation.  Take for example a simple 6 digit client number; if you place this in a list the system will generate something like:

<div id="lf_10000_1_1" class="iLvCol" style="width: 120px;">999999</div>

Which is 72 characters long.  If you apply this to hundreds of thousands of records the size of the web page can exceed the capacity of the workstation.

You can also hit the default memory limits of 32MB set for any PxPlus sessions.  We suggest if you are using large files which may generate large HTML pages that you set the 'IZ' system parameter to eliminate this limit.

Another thing you need to watch out for is the time required to render a page.  Chrome and other browsers will attempt to re-load a page should it take too long to respond.  So if your logic to handle the 1GB of data takes much more than about 5-10 seconds to process the data, you should include a progress bar which will let the browser and the user know that the system is still working on your request.  This is a good idea regardless of whether you are running using iNomads or regular Nomads.  You also need to remember that iNomads, a as web page, defers physical screen updates until your application requests more input.  So if you are displaying a list box and adding to it a few lines at a time, in Nomads the user will see these updates as they happen, however in iNomads this list has to be completely loaded before the page can be rendered.  This is where a progress bar can help.
Mike King
President - BBSysco Consulting
eMail: mike.king@bbsysco.com