Migrate operation synchronises two schemas located in different database connections. Operation runs only with one schema selected, which is used as a source schema. Target connection and also target schemas are other two inputs of the migrate operation. Target connection is selected by user. Target schema is selected automatically. If schema with the same ID as source schema already exists in that database connection, it is selected as a target schema. If such a schema doesn't exist, target schema is created using name and ID of source schema.
There are two options sections. The first one is for global items (with no owners). Options can be combined.
Do not update items option will avoid updating items that exists even in target schema
Do not add items option will avoid adding new items that exists only in source schema
Do not delete items option will avoid deleting items that exists only in target schema
Second option section contains list of users and the same three options as for global items. The difference is that they work for selected user's items only. After enabling users list by checkbox above, you have to select at least one user to apply selected options for.