Oracle Database 18c: What are the top features you should know?
Oracle Database 18c was already launched in February 2018, and true to the company’s cloud-first strategy, it is also available on engineered systems and the cloud. If you still have not heard of what it can do, here are the features that you should know about.
Availability related features
- You can now do block change tracking files for RMAN backups in Oracle Data Guard.
- Multiple-instance redo apply now allows for block change tracking backups, allowing you to do incremental backups for your large databases when master & slave are Real Application Clusters.
- There are now two new logging modes for standby that makes loading data faster. The Standby Nologging for Data Availability will wait until all standbys have applied data before committing a loading operation. The other is Standby Nologging for Load Performance, which will not transmit data when there is a bottleneck in your network when data is loading.
- You can now create shadow tablespaces for data protection. It is similar to MySQL’s double write feature.
- If you do backup from non-container database, it is going to be available when you migrate to CDB.
- Oracle Database 18c can treat shards and catalogs as a portable database.
- The new Oracle Database 18c allows you to specify mapping of data to different shards using user-defined sharding method.
- You can now use MULTISHARD_QUERY_DATA_CONSISTENCY to set data consistency when making queries on multiple shards.
- You can manually terminate run-away queries without disrupting the session.
Features related to big data and data warehousing
- Three functions were introduced in 18c: APPROX_SUM, APPROX_COUNT, and APPROX_RANK to help you do more with approximate query processing.
- Big Data SQL and in-memory columnar now support LOB objects.
- Automatic in-memory flushes out IM columns that are not accessed frequently in the event that there is insufficient memory.
- External tables can now use Database In-Memory features.
- You can now set a memoptimize pool size in the system global area, which can then be utilized for fast searches.
RAC and Grid related features
- You can now clone portable databases with automatic storage management.
- You can now convert your disk groups to flex disk groups without needing restricted mount.
General features that you should know of
- You now have two additional parameters that you can use when creating portable databases in Active Data Guard: STANDBY_PDB_SOURCE_FILE_DIRECTORY and STANDBY_PDB_SOURCE_FILE_DBLINK.
- The PDB Lockdown Profile has been enhanced with three default profiles: SAAS, PUBLIC_DBAAS, and PRIVATE_DBAAS.
- The new Oracle Database 18c now has better PDB refresh with new support for switchover.
- The PDB Snapshot Carousel will have eight copies. These copies are backed up within 24 hours.
- Changed the password file path to ORACLE_BASE instead of ORACLE_HOME.
- You can make Oracle Home read-only with dbca or roohctl –enable. To confirm if it is read-only, you can run the orabasehome command.
- You can now merge partitions and subpartitions while still online.
- You can now run the SQL Performance Analyzer in parallel, so that you do not waste time doing tests.
- You can now use Microsoft Active Directory services with Oracle Database, without needing to interact with Oracle Enterprise User Security.
- You also have new initialization parameters, such as
- UNIFIED_AUDIT_SYSTEMLOG, and
- SLEEP replaces DBMS_LOCK.SLEEP.
Photo courtesy of Oracle Corporate Communications (Flickr).