Oracle 12cR1 New Features

Database:

• New background processes – LREG (Listener Registration), SA (SGA Allocator), RM.
• RESOURCE role does not include UNLIMITED TABLESPACE anymore.
• No need to shutdown database for changing archive log mode.
• Like sysdba, sysoper & sysasm, we have new privileges, in Oracle 12.1.0.
  sysbackup for Backup operations
  sysdg for Data Guard operations
  syskm for Key management
• Like sys, system, we have new default SYS users, in Oracle 12c Release1.
  sysbackup for Backup operations
  sysdg for Data Guard operations
  syskm for Key management
• Oracle Database 12c Data Pump will allow turning off redo for the import operation (only).
  $ impdp … transform=disable_archive_logging:y
• expdp has transport view, view_as_tables options.
  $ expdp … VIEWS_AS_TABLES=test_view
• New ENCRYPTION_PWD_PROMPT parameter allows you to specify whether Data Pump should prompt you for the encryption password, rather than you entering it on the command line.
• Enhanced statistics —> frequency histograms can be created upto 2048 distinct values (increased from 254 distinct values), dynamic sampling up to eleven, and stats automatically gathered during load.
• Two new types of histograms introduced — top-frequency histograms and hybrid histograms.
• 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).
• Oracle 12c includes database level redaction, allowing granular control of access to sensitive data.
• Dynamic sampling has been renamed to Dynamic Statistics in Oracle 12c release 1.
• Multi threaded database with parameter threaded_executions. Multiple processes and multiple threads within each process, provides improved performance and manageability through more efficient sharing of system and processor resources.
• Oracle introduced parameter PGA_AGGREGATE_LIMIT which is a real/PGA memory limit.
• UNDO for temporary tables can now be managed in TEMP, rather than the regular UNDO tablespace. Queried through v$tempundostat.
• Oracle Enterprise Manage Express (lightweight EM Cloud Control 12c version), replaces the Oracle Database console and, is installed automatically.
• enable_ddl_logging – when the logging of DDL statements is enabled, DDL statements are recorded in a separateDDL log (instead of the alert log file).
• Some information, that can be used to debug a problem, is recorded in a separate debug log instead of the alert log.
• Oracle Caching mode: It enables to force caching of all segments into buffer cache automatically(when the segments are accessed). ALTER DATABASE FORCE FULL DATABASE CACHING;
• Database Smart Flash Cache support for multiple flash devices – A database instance can access and combine multiple flash devices for Database Smart Flash Cache without requiring a volume manager.
• New type of sequences – session sequences, for global temporary tables
• Materialized View out-of-place refresh.
  DBMS_MVIEW.REFRESH(‘TEST_MV’, method => ‘?’, atomic_refresh => FALSE, out_of_place => TRUE);
• CSSCAN (Character Set Scanner) and CSALTER utilities replaced with DMU (Database Migration Assistant for Unicode).
• Monitor the privilege assignments easy in 12c Oracle with DBMS_PRIVILEGE_CAPTURE.
• SELECT ANY DICTIONARY no longer provides access to tables with password hashes (USER$ etc).
• Lateral Views – a lateral view is a view that references columns from a table that is not inside the view.
• Reduces the size of redo associated with recovering the regular UNDO tablespace.

ASM: (Oracle Grid Infrastructure new features)

• Introduction of Flex ASM, ASM would run only on 3 instances on a cluster even if more than 3, the instances that not have an ASM would request remote ASM, typically like SCAN. In normal conditions in a node if ASM fails the entire node will be useless, where in 12c the ability to get the extent map from remote ASM instance makes the node useful.
• 12.1.0.2 introduced a new ASM feature which might prevent us from adding dissimilar size disks into a normal or high redundancy disk groups.
• Introduction of Flex Cluster, with light weight cluster stack, leaf node and traditional stack hub node, application layer is the typical example of leaf nodes where they don’t require any network heartbeat.

RMAN:

• Table (or table partition) Point-In-Time Recovery (combination of Data Pump and RMAN, auxiliary instance required). The table is recovered into an auxiliary instance and there is the option to import the recovered table into a new table or partition using REMAP option or create the expdp dump of the recovered table only, for import at a later time of your choosing.
  RMAN> recover table table_name until scn scn_number auxiliary destination on ‘path’;
  RMAN> recover table sh:sales:P1 remap table sh.sales:P1:new_tab
• Running SQL commands and executing PLSQL procedures in RMAN without SQL keyword.
  RMAN> select * from v$session;
• Recover or copy files from Standby databases. 
  Refresh a single datafile on the primary from the standby (or standby from primary).
• Multi-sectional backup functionality, to improve backup and restore operation of large size data files, extended further in 12c to supports image copies and incremental backups along with the full database backupsets.
• Table level restoration i.e object level.
• Incremental recovery more faster, many of the tasks removed.
• In Oracle 12c, ACTIVE DUPLICATE DATABASE doesn’t not required any pre backup existence to clone the database, RMAN first takes backup of datafiles into backupsets, and transmit to the auxiliary location and will be restored/recovered subsequently.
• New NOOPEN clause in 12c ACTIVE DUPLICATE DATABASE, will prevent opening database immediately after the cloning process completion and the database will remain in MOUNT state and we have to manually open the database.
• Rolling forward/Synchronizing a standby database.

Partitioning:

• Partitioning enhancements (partition truncate, cascading, global index cleanup, online moving of a partition)
• SQL> ALTER TABLE … MOVE PARTITION … ONLINE…
• Multiple partition operations in a single DDL.
• Interval-Ref Partitions – we can create a ref partition (to relate several tables with the same partitions) as a sub-partition to the interval type.
• Cascade for TRUNCATE and EXCHANGE partition.
• Asynchronous Global Index maintenance for DROP and TRUNCATE. Command returns instantly, but index cleanup happens later.
• Online move of a partition(without DBMS_REDEFINTIION) – DML operations can continue to run uninterrupted on a partition or subpartition that is being moved without using online table redefinition.