1. Mark Jones
  2. PowerBuilder
  3. Wednesday, 15 February 2023 16:07 PM UTC

Does anyone know what are the limitation on size of expressions (e.g. visibility,  computed fields, protect) on datawindows? And, what if you have multiple long expressions on the same datawindow? 

I have been fooling around with a very long protect expression (28k) and it makes the datawindow unstable.   I can edit the datawindow and insert the expression with no errors but when I save the datawindow it crashed PB and the object ends up as garbage in the PBL.   W We allow our customers to create their own datawindows via our application and we need to put reasonable constraints on what they can enter (right now our limit is 2K per field) .  I cannot find any documentation that says what are the actual property expression size limits.





Miguel Leeuwe Accepted Answer Pending Moderation
  1. Wednesday, 15 February 2023 18:25 PM UTC
  2. PowerBuilder
  3. # 1

I don't think it's recommended practice, but it works so well: use a global function in your dw attributes that returns the value you need.

Might make things more stable, but not guaranteed, just worth to give it a try.



  1. Chris Pollach @Appeon
  2. Wednesday, 15 February 2023 20:40 PM UTC
Hi Miguel;

Global functions are great now since PB 8.0 as Sybase optimized the Class Pool & Instance Pool handling greatly. :-)

Of course, calling GF's for each row on a 1M row result set is still not recommended. ;-)

Regards ... Chris
  1. Helpful 1
  1. Miguel Leeuwe
  2. Wednesday, 15 February 2023 23:43 PM UTC
Yes, we use them ourselves everywhere, but of course our max amount of rows is like 50,000
  1. Helpful 1
  1. Mark Jones
  2. Friday, 31 March 2023 14:05 PM UTC
Thanks for suggestions regarding global functions. We actually use global functions extensively in datawindows in our system. It allows us to give our customers (who build their own reports using Infomaker) advanced functionality and features. GFs do however affect performance for large datasets.

However, does anyone know what the actual maximum attribute expression length would be?
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