I have created a report with custom filters and a custom button for updating rows.
The problem is when I push the button and the update starts it lasts some time and I don't have any feedback when it is finished.
Is it possible to create a messagebox that would appear once the update is finished?
If you are using an on submit page process then you are able to enter a success or fail message to display once the process is complete and the page reloads, see: 8.5 Understanding Page Processes
To display the message you will need on-submit after page processing branch that has the "include process success message" box checked.
If you are not using this method then you would need describe how the update happens.
Hope this helps.
I guess you are updating using DA.
You can do one thing here.
Create a DA
Execute your PL/SQL Code and set success message to one of the page items and return that value from the PL/SQL Code you just executed