Importing into Existing Tables
This section describes factors to take into account when you import data into existing tables.
Manually Creating Tables Before Importing Data
When you choose to create tables manually before importing data into them from an export file, you should use either the same table definition previously used or a compatible format. For example, although you can increase the width of columns and change their order, you cannot do the following:
Add NOT NULL columns
Change the datatype of a column to an incompatible datatype (LONG to NUMBER, for example)
Change the definition of object types used in a table
Change DEFAULT column values
When tables are manually created before data is imported, the CREATE TABLE statement in the export dump file will fail because the table already exists. To avoid this failure and continue loading data into the table, set the import parameter IGNORE=y. Otherwise, no data will be loaded into the table because of the table creation error.
Do you want to support this ? Seems like a reasonable thing to have - currently, an error is thrown during import
if the table already exists ?