COMPRESSION =(METADATA_ONLY | NONE) - This parameter applies from Oracle 10.2. It specifies whether to compress metadata before writing to the dump file set. Compression reduces the amount of disk space consumed by dump files.

You’ll need the IMPORT_FULL_DATABASE role to perform an import if the dump file for the import was created using the EXPORT_FULL_DATABASE role.

The Data Pump import utility uses the PARFILE, DIRECTORY, DUMPFILE, LOGFILE, and NOLOGFILE commands in the same way as the Data Pump exportutility.

SQLFILE - This parameter enables you to extract the DDL from the export dump file, without importing any data.

REUSE_DATAFILES - This parameter tells Data Pump whether it should use existing datafiles for creating tablespaces during an import.

You can perform a Data Pump import in various modes, using the TABLE, SCHEMAS, TABLESPACES, and FULL parameters, just as in the case of the Data Pump export utility.

The Data Pump import utility uses the CONTENT, EXCLUDE and INCLUDE parameters in the same way as the Data Pump export utility. If you use the CONTENT=DATA_ONLY option, you cannot use either the EXCLUDE or INCLUDE parameter during an import.

QUERY can also be used but in this case Data Pump will use only the external table data method, rather than the direct-path method, to access the data.

TABLE_EXISTS_ACTION - Use this parameter to tell Data Pump what to do when

a table already exists.

o SKIP (the default), Data Pump will skip a table if it exists.

o APPEND value appends rows to the table.

o TRUNCATE value truncates the table and reloads the data from the    export dump file.

o REPLACE value drops the table if it exists, recreates, and reloads it.

The JOB_NAME, STATUS, and PARALLEL parameters carry identical meanings as their Data Pump export counterparts.

You can perform a Data Pump import in various modes, using the TABLES, SCHEMAS, TABLESPACES, and FULL parameters, just as in the case of the Data Pump export utility.

REMAP_SCHEMA - Using this parameter, you can move objects from one schema to another.

Changes the name of the source datafile to the target datafile name in all SQL statements where the source datafile is referenced: CREATE TABLESPACE, CREATE LIBRARY, and CREATE DIRECTORY.

Remapping datafiles is useful when you move databases between platforms that have different file naming conventions.

REMAP_TABLESPACE - This parameter enables you to move objects from one
tablespace into a different tablespace during an import.

NETWORK_LINK - In case of network import, the server contacts the remote source
database referenced by the parameter value, retrieves the data, and writes it directly back to the target database. There are no dump files involved.

EXCLUDE=CONSTRAINT - The log file is written to dpump_dir1, specified on the DIRECTORY parameter.

TRANSFORM - This parameter instructs the Data Pump import job to modify the storage attributes of the DDL that creates the objects during the import job.

SEGMENT_ATTRIBUTES - If the value is specified as y, then segment attributes (physical attributes, storage attributes, tablespaces, and logging) are included, with appropriate DDL. The default is y.

STORAGE - If the value is specified as y, the storage clauses are included, with appropriate DDL. The default is y. This parameter is ignored if SEGMENT_ATTRIBUTES=n.

OID - If the value is specified as n, the assignment of the exported OID during the creation of object tables and types is inhibited. Instead, a new OID is assigned. This can be useful for cloning schemas, but does not affect referenced objects. The default is y.

PCTSPACE - It accepts a greater-than-zero number. It represents the percentage multiplier used to alter extent allocations and the size of data files.

object_type: It can take one of the following values: