Data Pump Faqs

Frequently Asked Questions

Why are directory objects needed?

They are needed to ensure data security and integrity. Otherwise, users would be able to read
data that they should not have access to and perform unwarranted operations on the server.

What makes Data Pump faster than original Export and Import?

There are three main reasons that Data Pump is faster than original Export and Import. First,
the Direct Path data access method (which permits the server to bypass SQL and go right to
the data blocks on disk) has been rewritten to be much more efficient and now supports Data
Pump Import and Export. Second, because Data Pump does its processing on the server
rather than in the client, much less data has to be moved between client and server. Finally,
Data Pump was designed from the ground up to take advantage of modern hardware and
operating system architectures in ways that original Export/ and Import cannot. These factors
combine to produce significant performance improvements for Data Pump over original
Export and Import.

How much faster is Data Pump than the original Export and Import utilities?

For a single stream, Data Pump Export is approximately 2 times faster than original Export
and Data Pump Import is approximately 15 to 40 times faster than original Import. Speed
can be dramatically improved using the PARALLEL parameter.

Why is Data Pump slower on small jobs?


Data Pump was designed for big jobs with lots of data. Each Data Pump job has a master
table that has all the information about the job and is needed for restartability. The overhead
of creating this master table makes small jobs take longer, but the speed in processing large
amounts of data gives Data Pump a significant advantage in medium and larger jobs.

Are original Export and Import going away?

Original Export is being deprecated with the Oracle Database 11g release. Original Import
will always be supported so that dump files from earlier releases (release 5.0 and later) will be
able to be imported. Original and Data Pump dump file formats are not compatible.

Are Data Pump dump files and original Export and Import dump files compatible.

No, the dump files are not compatible or interchangeable. If you have original Export dump
files, you must use original Import to load them.

How can I monitor my Data Pump jobs to see what is going on?

In interactive mode, you can get a lot of detail through the STATUS command. In
SQL, you can query the following views:
• DBA_DATAPUMP_JOBS - all active Data Pump jobs and the state of each job
• USER_DATAPUMP_JOBS – summary of the user’s active Data Pump jobs
• DBA_DATAPUMP_SESSIONS – all active user sessions that are attached to a Data Pump
job
• V$SESSION_LONGOPS – shows all progress on each active Data Pump job

Can I use Oracle Enterprise Manager with Data Pump?

Yes, OEM supports a fully functional interface to Data Pump.

Can I use gzip with Data Pump?

Because Data Pump uses parallel operations to achieve its high performance, you cannot pipe
the output of Data Pump export through gzip. Starting in Oracle Database 11g, the
COMPRESSION parameter can be used to compress a Data Pump dump file as it is being
created. The COMPRESSION parameter is available as part of the Advanced Compression
Option for Oracle Database 11g.

Conclusion 

Data Pump is fast and flexible. It replaces original Export and Import starting in Oracle Database 10g. Moving to Data Pump is easy, and opens up a world of new options and features.