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
4IMP: fromuser, touserIMPDP: remap_schema

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.



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