As the xmlmodelUpdate function updates binds by discarding and reconstructing the entire effected memory model, it is an expensive call to make from a performance perspective. Minimizing the number of xmlmodelUpdate function calls that are made will decrease the length of time users must wait for the form to update.
The xmlmodelUpdate function updates the XML (not XForms) data model in the form. This is useful if computes have changed the structure of the data model in some way, such as changing or adding bindings. These sorts of changes do not take effect until the function is called. The larger the data model your form has, the longer it takes to load and update. Most of this speed loss comes from updating the binds between the data model and the presentation layer. When a model is updated using the xmlmodelUpdate function, the entire memory model for these binds is discarded and reconstructed from scratch. This means the forms with a lot of binds may run more slowly, especially when working with tables that allow users to add and delete table rows. As the user adds more rows to a table, the time it takes to update the data model will increase marginally, since there are now more items to link to the model. This generally is not a problem in forms with smaller data models, but can become quite cumbersome in forms with large data models and many binds.
If adding rows becomes a performance issue, try to design your form so that you always provide the number of rows you expect a typical user to complete. Additionally, you can experiment with allowing users to add multiple rows to the table at a time, as this will also limit the number of xmlmodelUpdate functions that are called. However, adding multiple rows to a table may cause other performance issues. You should always test your forms to see which combination of practices provide the best performance for your application.
No examples provided.
Exceptions to this practice
There are no exceptions to this practice.