Difference between exp/imp and expdp/impdp ?

Below Are the differences in tradionational exp/imp vs Datapump

• Datapump operates on a group of files called dump file sets. However, normal export operates on a single file.
• Datapump access files in the server (using ORACLE directories). Traditional export can access files in client and server both (not using ORACLE directories).
• Exports (exp/imp) represent database metadata information as DDLs in the dump file, but in datapump, it represents in XML document format.
• Datapump has parallel execution but in exp/imp single stream execution.
• Datapump does not support sequential media like tapes, but traditional export supports.
• Impdp/Expdp use parallel execution rather than a single stream of execution, for improved performance.
•  Data Pump will recreate the user, whereas the old imp utility required the DBA to create the user ID before importing.
• In Data Pump, we can stop and restart the jobs.

Why expdp is faster than exp (or) why Data Pump is faster than conventional export/import.

• Data Pump is block mode, exp is byte mode.
• Data Pump will do parallel execution.
• Data Pump uses direct path API.
• In Data Pump, where the jobs info will be stored (or) if you restart a job in Data Pump, how it will know from where to resume – Whenever Data Pump export or import is running, Oracle will create a table with the JOB_NAME and will be deleted once the job is done. From this table, Oracle will find out how much job has completed and from where to continue etc.
• Default export job name will be SYS_EXPORT_XXXX_01, where XXXX can be FULL or SCHEMA or TABLE.
• Default import job name will be SYS_IMPORT_XXXX_01, where XXXX can be FULL or SCHEMA or TABLE.
• Datapump gives 15 – 50% performance improvement than exp/imp.
• Export and import can be taken over the network using database links even without generating the dump file using NETWORK_LINK parameter.
•  CONTENT parameter gives the freedom for what to export with options METADATA ONLY, DATA, BOTH.
• Few parameter name changes in datapump and it always makes confusion with parameters in normal exp/imp

How you can check data dump dump file is taken by exp or expdp?

For Conventional export, the logfile ends with “Export Terminated”

$ tail -1 exp_user1.log

Export terminated successfully without warnings.

For Data pump the logfile ends with “Job”

$ tail -1 expdp_user1.log

Job “SYS”.”SYS_EXPORT_SCHEMA_01″ successfully completed.

The simplest way would be: just run the imp, if it throws error , then its created through expdp, because dump from expdp cannot be used with imp and vice versa. So that could help you find.