Migration Effects on Users' Old Database Schemas

If shared schema mapping is not used, then users retain their old database schemas. If shared schema mapping is used, then users' local schemas are dropped from the database, and they are mapped to a shared schema that the enterprise user administrator creates for this purpose before performing the migration. When migrated users own database objects in their old local database schemas, administrators can specify that the schema and objects are not to be dropped by setting the CASCADE parameter to NO. When the CASCADE parameter is set to NO, users who own database objects in their old local schemas do not migrate successfully so their objects are not dropped.

If some users want to retain the objects in their local database schemas and be mapped to a shared schema, then the administrator can manually migrate those objects to the shared schema before performing the bulk user migration. However, when objects are migrated to a shared schema, they are shared among all users who share that new schema.

Table A-3 summarizes the effects of setting the MAPSCHEMA and CASCADE parameters.


Table A-3 Effects of Choosing Shared Schema Mapping with CASCADE Options

MAPSCHEMA Parameter Setting CASCADEParameter Setting User MigrationSuccessful? User SchemaObjects Dropped?

PRIVATE

NO (default setting)

Yes

No

SHARED

NO

Yes1

No

SHARED

YES

Yes2

Yes


See Also:

"User Migration Utility Parameters" for detailed information about the MAPSCHEMA, CASCADE, and other parameters that can be used with this utility

1

Users migrate successfully only if they do not own objects in their old database schemas; otherwise, they fail.

2

Users migrate successfully, and their old database schemas are dropped.