Oracle 12C new features

New features in Oracle Database 12c:
 

  ·    Oracle Database 12c, c for cloud, a multi-tenant database management system, with nearly 500 new features.

  ·   Increased size limit for VARCHAR2, NVARCHAR2, RAW data types to 32K.

  ·    Oracle Database 12c has new feature called "Identity Columns" which are auto-incremented at the time of insertion (like MySQL).

  ·    Temporary undo (for global temporary tables) will not generate undo.

  ·    Oracle Database 12c Data Pump will allow to turn off redo for the import operation only.

  ·     Enhanced statistics (Hybrid histograms for more than 254 distinct values, dynamic sampling up to eleven, stats automatically gathered during load).

  ·    No need to shutdown database to take out of archive log mode.

  ·    Row pattern matching - "MATCH_RECOGNIZATION" (identification of patterns within a table ordered/sorted by the SQL statement).

  ·    Adaptive execution plans (change of the plan at runtime).

  ·    Centralised patching.

  ·    We can test patches on database copies, rolling patches out centrally once testing is complete.

  ·     PL/SQL inside SQL: this new feature allows to use DDL inside SQL statements (i. e.: to create a one shot function)

  ·     The object DEFAULT clause has been enhanced. Adding a column to an existing table with a default value (much faster with Oracle 12c and it consumes less space than before, pointer to the Oracle Data Dictionary), applies also to sequences, identity types etc...

  ·      Partitioning enhancements (partition truncate, cascading, global index cleanup, online moving of a partition, ...)

  ·     Oracle 12c includes database level redaction, allowing granular control of access to sensitive data.

- ·     Pagination query, SQL keywords (LIMIT) to replace ROWNUM records

Compression:

  ·      Automated compression with heat map.

  ·      Optimisation can be run on live databases with no disruption. Data optimization will monitor the data usage and with policy archive old data and hot data will be compressed for faster access. Inactive data can be more aggressively compressed or archived, greatly reducing storage costs.

  ·       Advanced Row compression(for Hot Data).

  ·       Columnar Query compression(for Warm Data).

  ·      Columnar Archive compression(for Archive Data).

Data Guard:

  ·      Oracle Database 12c introduces a new redo transportation method which omits the acknowledgement (to primary) of the transaction on the standby. This feature is called "Fast Sync" redo transport.

  ·       creating a new type of redo destination called "Far Sync Standby". A "Far Sync Standby" is composed only of the standby control files, the standby redo logs and some disk space for archive logs which shall be sent to the Standby database. Failover & Switchover operations are totally transparent as the "Far Sync Standby" cannot be used as the target.

  ·       Data Guard Broker commands have been extended. The "validate database" command to checks whether the database is ready for a role transition or not.

Pluggable Databases:

  ·         In Oracle 12c, in a pluggable database environment, we can create a single database container, and plug multiple databases into this container. All these databases then share the exact same oracle server/background  processes and memory, unlike the previous versions where each database has its own background processes and shared memory. This helps in database consolidation and reduce the overhead of managing multiple desperate databases.

  ·         Container Database (CDB): is the core data dictionary objects that comes after an Oracle database installation.

  ·         Pluggable Database (PDB): Data dictionary objects and data related to the application. We can have many PDB plugged into a single CDB.

  ·       All Oracle database options/features are available on the PDB level.

  ·       RMAN backup at CDB level.

  ·       We can unplug a PDB from a CDB to another CDB.

  ·        PDB's can be cloned inside the CDB.

  ·        Management of PDB (clone/creation/plug/unplug/drop) are implemented as SQLs.

  ·       Extremely fast PDB-provisioning (clone inside the CDB).

  ·       Database patch/upgrade management very quick as CDB is a single point of installation.

  ·       Each PDB has its own data dictionary.

  ·       Data Guard configuration on CDB as whole.

  ·       RMAN point-in-time recovery at PDB level (while other PDB's remains open).

  ·       Flashback of a PDB should be available for Oracle 12c Release 2.

  ·       Entire containers can be backed up in single run, regardless of how many databases they contain.
  ·       Upgrade one container database and all pluggable databases are upgraded.