With 4D v16, you can improve your database scalability using the new 4D Write Pro commands in preemptive processes.
If you are doing routines for creating or converting documents programmatically – e.g. invoices … you can now do it with preemptive workers as most 4D Write Pro commands are now thread safe!
The list of thread-safe 4D Write Pro commands is already long:
- WP New
- WP Import document
- WP EXPORT VARIABLE
- WP EXPORT DOCUMENT
- WP Get range
- WP GET PARAGRAPHS
- WP GET PICTURES
- WP SET ATTRIBUTES
- WP GET ATTRIBUTES
- WP RESET ATTRIBUTES
- WP Is font style supported
- FONT STYLE LIST
- FONT LIST
- WP INSERT BREAK
- WP INSERT DOCUMENT
- WP DELETE BOOKMARK
- WP Get bookmark range
- WP GET BOOKMARKS
- WP CREATE BOOKMARK
You can check in the documentation to see which commands are thread safe with this icon: 
If you want to know more about preemptive processes, just take a look at this post!