Log changes to the database during upgrades
Sitefinity CMS logs all database schema changes applied during the upgrade phase. For example, adding a new column to an existing table: ALTER TABLE table_name ALTER COLUMN column_name datatype
The Data Definition Language (DDL) statement for each update is recorded in the UpgradeTrace.log. The file is located in the ~\App_Data\Sitefinity\Logs folder of your project.
Together with the DDL migration statements, Sitefinity CMS stores additional information that describes the entire database schema migration process in general:
    - The complexity of the schema migration:
    
        - Trivial - contains schema artifacts without influencing the existing schema
 
        - Extending - contains schema artifacts that extend the existing schema
 
        - Complex - contains schema artifacts with structural changes
 
    
     
    - Types of the schema changes to be applied to the underlying database:
    
        - Adding new artifacts:
        
        
            - Adding columns on an existing tables
             
            - Adding foreign key constraints to existing tables
             
            - Adding foreign key constraints to new tables - the create table statement is included as well
             
            - Adding indices to existing tables
             
            - Adding indices definition for new tables - the create table statement is included as well
             
            - Adding new tables
             
            - Adding structures independent of existing
             
            - Adding primary key constraints to existing tables
             
            - Adding primary key constraints to new tables - the create table statement is included as well
             
        
         
        - Modifying existing artifacts:
        
        
            - Modifying columns of existing tables
             
            - Modifying existing structures
             
        
         
        - Removing existing artifacts:
        
        
            - Removing columns from existing tables
             
            - Removing foreign key constraints from existing tables
             
            - Removing indices from existing tables
             
            - Removing primary key constraints from existing tables
             
        
         
        - Using temporary tables to migrate data during structural table changes
         
    
     
EXAMPLE: Following is an example of the contents of the UpgradeTrace.log file after a complex schema migration:
EXAMPLE: Following is an example of the contents of the UpgradeTrace.log file after an extending schema migration: