Starting with Oracle Database 12cR1 (22.214.171.124), a new static pool in the SGA is designed to store data in the columnar format and is called In-Memory Column Store (IMCS). Each table column is stored as a separate structure in IMCS. The In-Memory column store does not replace the buffer cache, rather supplements by storing data in columnar format.
Following the levels at which IMCS can be enabled at:
- Partition / sub-partition
- Materialized view
Like other Oracle Database Options, you make NO changes in your application to start benefiting from the In-Memory Option. It is completely transparent to the applications. Also, Oracle Optimizer is fully aware of the column format and automatically utilizing IMCS when required.
I plan to test and blog more on the In-Memory option. Following are few of the topics that I plan to post a blog entry on:
- Enable and disable In-Memory Option
- In-Memory Option at various levels
- In-Memory Space pressure
- In-Memory background processes
- In-Memory with compression levels
- In-Memory statistics
- In-Memory and Data Pump Export
- In-Memory with Multi-tenant Option