COMPRESSION parameter is used with EXPDP, to compress the generated dump file.

NOTE – For using compression parameter with datapump, we need to have Oracle advance compression license.

 

COMPRESSION
Reduce the size of a dump file.
Valid keyword values are: ALL, DATA_ONLY, [METADATA_ONLY] and NONE.

In this below demo, we will compare the dump size with or without compression parameter.

 

Get the DUMPSIZE without COMPRESSION parameter :

So, without compression, the size is around 25 MB. Let’s do the export with compression.

EXPORT WITH COMPRESSION=ALL

We can see, from 25 MB ,it came down to 2 MB :). It really saves a lot of disk space.

However, there is a tradeoff. Use of compression will increase the time required for the export job.

 

W/O COMPRESSIONWITH COMPRESSION
SPACE REQUIRED25mb3 mb
TIME TAKEN3 second5 second
CPU USAGENORMALbit more than w/o compression
LICENSE?No additional licenseAdvance compression license required

 

COMPRESSION_ALGORITHM:

We can control the compression ratio using COMPRESSION_ALGORITHM parameter. HIGH compression ratio will use more CPU and also increase export job time.

 

COMPRESSION_ALGORITHM
Specify the compression algorithm that should be used.
Valid keyword values are: [BASIC], LOW, MEDIUM and HIGH.

 

PARFILE WILL LOOK AS BELOW: