When developing or maintaining a 4D application, you may need to modify the database structure after deployment—something not possible with a compressed .4DZ file, where the structure is protected. In 4D project mode, deploying an application as a compressed .4DZ file locks the structure, making it unmodifiable. This is great for production but problematic during development or testing when you need to:

• Add or alter tables using SQL commands (e.g., CREATE TABLE).
  

• Use REGENERATE MISSING TABLE() to sync the data file with an updated structure.

To make the structure modifiable after deployment, deploy your application as an uncompressed project folder instead of a .4DZ file. In your build configuration file, set the PackProject key to False:

<PackProject>False</PackProject>

This prevents the project from being compressed during the build process. An uncompressed folder exposes the structure and potentially the source code. Always strip out .4dm files before deployment. For production, stick to a compressed .4DZ file to protect the structure and ensure stability. Structure changes shouldn’t occur in production.