7.1.6 Faster Encrypted Table Smart Scans

Scans of encrypted tables stored in the in-memory columnar format have been improved by decrypting columns only when needed. Columns in the SELECT set or predicates are the only columns decrypted, not the entire flash cache cacheline. If the first predicate does not return any matches, then the columns for the second predicate are not accessed. This feature has up to 30% faster encrypted smart scans and reduced storage server CPU usage.

For example, consider the following query:

SELECT ename FROM emp 
WHERE job LIKE ‘%VP’ AND sal + bonus > 500000

Only the projected columns (ename) and one or more predicated columns are decrypted. The salary in data regions that do not have a VP are not accessed.

Minimum requirements:

• Oracle Exadata System Software release 19.3.0
• Oracle Database In-Memory option