In this example, all the Oracle data files’ consumed capacity is reported from the storage system. The first bar from the left shows that the storage consumed capacity of the data files was approximately 1.35 TB, as in this example, the PowerMax storage group compression was not enabled initially.
Figure 22. Example 2: PowerMax compression and deduplication of an encrypted Oracle database
We enabled PowerMax compression on data_sg and waited for the background compression to complete. At the end of the process, data_sg consumed only 465 GB, which translates to a 3.0:1 DRR. This result is not very different from the previous example where the database was created in an SG with compression already enabled.
Next, Oracle Transparent Database Encryption (TDE) was used to encrypt all the tablespaces. DBAs can choose to encrypt only certain table columns or a few tablespaces; however, we wanted to see the effect of encrypting the entire database. The result was that the data_sg storage consumption grew to 1.35 TB, or its original size. We can clearly see that database encryption negates the benefits of storage compression.
We did not create storage snapshots because we have already seen that they do not add capacity. We used the RMAN DUPLICATE command to clone the database. Initially, the target storage group did not have compression enabled. As a result, after RMAN finished, the total storage consumption doubled.
Finally, we enabled compression on the target storage group. PowerMax deduplication again provided 100 percent deduplication benefits and the storage consumption of both the source and target storage groups reverted to 1.35 TB.