Exp/Imp, Expdp/Impdp

Legacy EXPORT/IMPORT (exp/imp)

What is now known as legacy export/import (exp/imp) was introduced in Oracle 7.1  and were called  'conventional path exports' .  This meant that the  'conventional path export  used "SELECT * FROM OWNER.TABLE" to extract the data and push through various buffers and finally to the export file on the client side.  It wasn't until Oracle 7.3 that  'direct path exports' were introduced.  

• Exports broken up into 3 categories
• Incremental - will backup only the tables that have changed since the last incremental, cumulative or complete export.
• Cumulative - will backup only the tables that have changed since the last cumulative or complete export.
• Complete - will backup the entire database, with the exception of updates on tables where incremental and cumulative exports are tracked.  The parameter "INCTYPE=COMPLETE" must be specified for those tables with updates and are tracked to be backed up.
• Export broken up into 3 modes
• Exporting table - export table or group of tables
• Exporting users - can backup all objects in a particular users schema including tables/data/grants/indexes
• Exporting full database - exports the entire database
• Import broken into the same 3 modes as export
• Importing table/s
• Importing user/s
• Importing full database

Data pump EXPDP/IMPDP

Data pump expdp/impdp utilities were first introduced in Oracle 10g (10.1).  These new utilities were considered high performance replacements for the legacy export/import had been in use since Oracle 7.  Some of the key advantages are: greater data/metadata filtering, handling of partitioned tables during import and support of the full range of data types.

• Expdp/Impdp provide same categories and modes as the legacy exp/imp utility
• Plus more
• Legacy exp/imp commands are transformed into new parameters
• Legacy                   Data pump
• user/s                       schema/s
• file                           dumpfile
• log                           logfile
• For full list of all of the new parameter mappings visit this link for dp_legacy support documentation for 11.2 which is latest.  Oracle 11.2 DP_Legacy Parameter Mappings
• Expdp/Impdp offers ability to
• Stop/Kill/Attach to a datapump job
• Export/Import data in parallel
• Need to use the '%U' in your dumpfile name
• dumpfile=exp_test1_09202012_%U.dmp
• Expdp/Impdp major features
• Overall performance of datapump import is 15-45x faster than legacy import
• Network mode - allows import over dblink
• Restart - ability to stop and reattach to the job
• Include/Exclude - allow/disallow objects to be included/excluded during export/import
• Content - metadata_only, data_only or all
• Estimate - provides the estimated size of dumpfiles so space allocation can be made beforehand
• Compression - ability to compress your data up to 5x
• For a full review of the data pump performance and other features, please refer to the Oracle White Paper "Data Pump in Oracle 11gR2"

Differences

• Exp/Imp can be used from Oracle 7.1 on up to current release Oracle 11.2
• Expdp/Impdp can ONLY be used from Oracle 10.1 to current release Oracle 11.2
• Upgrading from a pre-10g Oracle database you must import your data using the current Oracle 11.2 legacy import utility as data pump was not available prior to Oracle 10.1
• Data pump exports present the data in an XML format
• Data pump will create the user as part of the import as previously with legacy import the dba would need to create the user beforehand and then recreate all of the necessary grants.
• With data pump you can stop and resume data pump jobs
• Data pump is a faster solution with better reliability and more automation.