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 data type of a column to an incompatible data type (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.