Use of Oracle exp/imp Export Import tool-2, expimp

Use of Oracle exp/imp Export Import tool-2, expimp

Iii. Problems with import tool imp

(1) The database object already exists.

Generally, tables, sequences, functions/processes, and triggers under the target data should be completely deleted before data is imported;

The database object already exists. If you use the default imp parameter, the Import fails.

If the ignore = y parameter is used, the data content in the exp file will be imported.

If the table has a constraint that contains a unique keyword, the table will not be imported if the condition is not met.

If the table does not have a constraint for a unique keyword, record duplication occurs.

(2) database objects are subject to primary and foreign key constraints

Data Import fails if it does not comply with the primary and foreign key constraints.

Solution: import the dependency table first.

The primary and foreign key constraints of the disable object to be imported. After the data is imported, enable them

(3) Insufficient Permissions

If you want to import user A's data to user B, user A must have the imp_full_database permission.

(4) failed to allocate storage when importing large tables (greater than 80 M)

Compress = Y for the default EXP, that is, compress all data into one data block.

If there is no continuous big data block during import, the import will fail.

When exporting a large table larger than 80 Mb, remember to compress = N, and this will not cause this error.

(5) imp AND exp use different character sets.

If the character set is different, the import will fail. You can change the unix environment variable or the information about NLS_LANG in the NT Registry.

After the import is complete, change it back.

(6) imp AND exp versions cannot be compatible

Imp can successfully import files generated by earlier exp versions. Files generated by later exp versions cannot be imported.