n is either 1 or 0. The default value is 0.
When DDLNo307 is enabled (n = 1), when an attempt is made to CREATE a primary key constraint to a table through DDL, and a primary key constraint already exists for that table, InterSystems IRIS® data platform suppresses the SQLCODE -307 error.
Changing This Parameter
On the SQL page of the Management Portal (System Administration > Configuration > SQL and Object Settings > SQL), select Ignore redundant DDL statements to suppress redundant SQLCODE errors.
You can also change DDLNo307 with the Config.SQLOpens in a new tab class (as described in the class reference) or by editing the CPF in a text editor (as described in the Editing the Active CPF section of the “Introduction to the Configuration Parameter File” chapter in this book).