I know this is a pretty old thread but we're running into the same issue. We have several tables in our app that contain a large number of rows. If we add columns to those tables in dev and deploy to prod the platform runs a script that updates default values for the new columns into every row. In our case that prod update can run 15+ minutes and causes an almost complete loss of use of our production system while the db does this massive single update transaction. Has anyone come up with a good, reliable way to work around this? At this point we can't add any new columns to these tables without facing this issue - I hate for the database design to be driven by a platform limitation. 

Anybody else work around this? Is it feasible to alter on new columns and set the defaults in a more controlled way (like maybe 1M rows at a time, avoiding an extended outage on the db) before doing the deploy? 

Following is the Outsystems response from a ticket we had open on this:

We tested this scenario to clarify if not defining the Default value when creating a new attribute in an Entity would avoid the creating of the Update Script:

• When creating a new attribute in an Entity with the type Integer the UpdateColumnDefaultValues.sql was created and it was updating the value to 0
• When creating a new attribute in an Entity with the type String the UpdateColumnDefaultValues.sql was created and it was updating the value to ''
• In any case, when a new attribute is added to an Entity the UpdateColumnDefaultValues.sql from the correspondent module will have a statement to update that value with the default defined in Service Studio or the default set automatically by the platform.
• Any attempt to avoid this behavior by tampering with the SQL script may be tempting, but will not be supported and may have unforeseen consequences. Therefore, we recommended avoiding this option at all.