Check Advanced Compression option usage on Oracle database


To check if the “advanced compression” Oracle database option was used on your environment is not so easy, as there are several activities that can activate this option.

For example for a mix Oracle 11.2.0.4 and 12.1.0.2 environment we can use the following query:

select * from DBA_FEATURE_USAGE_STATISTICS
where ((name like '%Compress%' and name not in ('Backup BASIC Compression','Backup BZIP2 Compression','SecureFile Compression (system)')) 
  and detected_usages>0)
or (name='Data Guard' and FEATURE_INFO like '%Compression used: TRUE%')
or (name in ('Oracle Utility Metadata API','Oracle Utility Datapump (Export)','Oracle Utility Datapump (Import)') 
  and version like '11.2.%' and feature_info not like '%compression used: 0 times%')
or (name in ('Oracle Utility Metadata API','Oracle Utility Datapump (Import)') 
  and version like '12.%' and feature_info like '%compression%')
or (name in ('Oracle Utility Datapump (Export)') 
  and version like '12.%' and feature_info not like '%compression used: 0 times%');

Why do we need so many filters? Because the text that shows if compression was used changes depending on the utility and Oracle version!
Below 3 different examples when compression was not used:

Version Utilities FEATURE_INFO text
12.1 Oracle Utility Datapump (Export) invoked: 1 times, compression used: 0 times (BASIC algorithm used: 0 times, LOW algorithm used: 0 times, MEDIUM algorithm used: 0 times, HIGH algorithm used: 0 times), encryption used: 0 times (AES128 algorithm used: 0 times, AES192 algorithm used: 0 times, AES256 algorithm used: 0 times, PASSWORD mode used: 0 times, DUAL mode used: 0 times, TRANSPARENT mode used: 0 times), parallel used: 0 times, full transportable used: 0 times
12.1 Oracle Utility Datapump (Import)

Oracle Utility Metadata API

invoked: 1 times, parallel used: 0 times, full transportable used: 0 times
11.2 Oracle Utility Metadata API invoked: 1 times, compression used: 0 times, encryption used: 0 times

Also, seems that for “Data Guard” utility the text has capital letters “%Compression used: TRUE%”.

More information about which features enable the usage of Advanced Compression option can be find here.

And how to avoid the usage of the Advanced Compression option by error on Mathias Zarick blog.

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