When architecting your ILM strategy you may decide to use the following different types of storage
- High performance tier where all the important and frequently accessed data is stored (Smaller faster disks).
- Low cost storage tier where the less frequently accessed data is stored (Larger slower, ATA disks).
- Online archive storage tier where all the data that is hardly or never accessed is stored (Low cost ATA disks).
Once you decide your classifications you could partition your tables accordingly (And then place different tablespaces on different type of storage) and then use Oracle ILM Assistant to maintain the tables and their data.
This calculator can be used to estimate the cost savings you might get by implementing such a strategy. (Remember this is only a very rough first estimate. Use values that you have received from your hardware vendor to use as inputs for cost per Gb of different tiers of storage).
All comments and suggestions, for corrections and improvements are welcome.