DBMS compression

does impdb into a compressed table really compress data?

Today at a customer we discussed the following scenario: To refresh a test database a datapump export and import was implemented. To save space on the test system the idea came up to compress the data on the test system.

DBMS compression: determining a table’s compression ratio

According to the Oracle documentation, the dbms_compression procedure allows to determine the compression ratio for a table without creating it. Let's have a look at it.