Oracle Database …
1 、Cross-Platform BACKUP and RESTORE ,这个增强很有用吧，你现在想把数据库搬的什么平台就搬，so easy！
2、DUPLICATE NOOPEN | SECTION SIZE
3、在线DDL增强：这些DDL不在需要blocking lock。drop index online Drop constraint online Set unused column online Alter index unusable online Alter index [visible | invisible]
4、12c数据文件也可以在线move了
5、Global Data Service (GDS) , 新服务理念，可以全局配置RAC、ADG、OGG，配置一个GDS就可以提供全部的服务。
6、现在可以不需要使用rownum来限制记录行数了，使用FETCH FIRST and OFFSET clause enable native SQL query to limit the number of rows returned. Cool!
7、DEFAULT_ON_NULL columns can be defined that refer to oracle sequence.这个增强在迁移到oracle时很有用。
8、某QQ群里某兄弟的想法在12c里面可以实现了：RMAN现在可以从备份里面restore／recover 表了。RECOVER TABLE
9、RMAN Command-Line:可以在RMAN里面执行SQL命令了，比如SELECT、DESCRIBE等
10、Asynchronous Global Index Maintenance for DROP and TRUNCATE Partition
Global index maintenance is decoupled from the DROP and TRUNCATE partition maintenance operation without rendering a global index unusable. Index maintenance is done asynchronously and can be delayed to a later point-in-time
11、Online Statistics Gathering for Bulk Loads
With online statistics gathering, statistics are automatically created as part of a bulk load operation such as a CREATE TABLE AS SELECT operation or an INSERT INTO ... SELECT operation on an empty table
12、Oracle Data Pump: Support SecureFile LOB as Default
The impdp command line has a new parameter (and DBMS_DATAPUMP has a new option) that tells Oracle Data Pump to create all LOBs as SecureFile LOBs. By default, beginning with Oracle Database 12c Release 1 (12.1), all LOB columns are created as SecureFile LOBs. However, Oracle Data Pump re-creates tables exactly as they existed in the exported database, so if a LOB column was a BASICFILE LOB in the exported database, Oracle Data Pump attempts to re-create it as a BASICFILE LOB in the imported database.
This feature allows the user to force creation of LOBs as SecureFile LOBs and to migrate to the latest more performant feature.
13、Pluggable Database
<wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr> A、Pluggable Databases Backup and Recovery
A container database (CDB) consists of zero or more Pluggable Databases (PDBs). Recovery Manager (RMAN) can backup the entire CDB and single or multiple PDBs to a consistent point-in-time. In addition, individual tablespaces or data files can be backed up from specific PDBs.
<wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr> B、Pluggable Databases Resource Plans
Oracle Resource Manager can manage resources on the container database (CDB) level and on the Pluggable Database (PDB) level. You can create a CDB resource plan that allocates resources to the entire CDB and to individual PDBs.
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14、Data Pump Export View As a Table
There is a new command-line option for Data Pump Export (expdp) that allows the user to indicate that a view should be exported as a table
15、Data Pump No Logging Option for Import
The new TRANSFORM option, DISABLE_ARCHIVE_LOGGING, to the impdp command line causes Data Pump to disable redo logging when loading data into tables and when creating indexes.
16、SQL*Loader Easy Mode
SQL*Loader has a new option that does not require the user to create a SQL*Loader control file. Instead, command-line parameters are used to specify how the data file is loaded.
17、ASM chown, chgrp, chmod and Open Files Support
This feature allows the ASMCMD chown, chgrp, and chmod commands to run even if the affected files are open. In Oracle Database 11g Release 2 (11.2), this was not allowed. The ALTER DISKGROUP MODIFY OWNERSHIP SQL command is also similarly modified, as this SQL provides support for these ASMCMD commands
18、PGA Size Limit
This feature limits the total amount of Program Global Area (PGA) that an instance can allocate, using a parameter called PGA_AGGREGATE_LIMIT. When the instance has allocated the PGA_AGGREGATE_LIMIT amount of PGA, sessions with the highest amount of allocated PGA are stopped until the limit is complied with.
This feature is important for consolidation because without a hard limit, the instance can become unstable due to excessive page. Excessive paging is one of the leading causes of instance eviction in an Oracle RAC database and can cause a multitude of performance and stability problems.
19、Asynchronous I/O Control for Direct NFS Client
The DNFS_BATCH_SIZE parameter controls the number of asynchronous I/O that can be queued by an Oracle process when Direct NFS client is enabled. In environments where the Network File Storage (NFS) server cannot handle a large number of outstanding asynchronous I/O requests, this parameter can be used to limit the number of I/O issued by an Oracle foreground process. The recommended setting for this parameter is to start at 128K and increase or decrease it based on NFS server performance.
20、Ability to Specify NFS Version in Direct NFS Client
The NFS_VERSION parameter allows the user to specify the NFS protocol to be used by Direct NFS client. Possible values are nfsv3, nfsv4, and nfsv4.1. If no version is specified, nfsv3 is used by default.
NFS Version 4 provides performance advantages over NFS Version 3, and the NFS_VERSION parameter allows the user to take advantage of those capabilities when available.
21、Network Acceleration and Data Compression Over Oracle Net Services
New SQL*Net parameters allow the compression of data transitioning over Oracle Net Services between client and server. Compression can be enabled at the:
■Connection level (connect string, URL)
■Service level (tnsnames.ora, ldap.ora)
■Database level (sqlnet.ora)
22、Very Large Network Buffers
Support for larger packets (SDU sizes) in the Oracle Net layer has been added in this release. Session data unit (SDU) defines the size of internal buffers. In previous releases, the default was 8K with a maximum of 64K. This release pushes the limit beyond the current values.
23、SYSBACKUP Administration Privilege
A new administration privilege, SYSBACKUP, allows Recovery Manager (RMAN) users to connect to the target database and run RMAN commands, no longer requiring SYSDBA.
24、Auditing Enabled By Default
Auditing is now enabled by default in Oracle Database 12c Release 1 (12.1) with no changes required to Oracle database initialization parameters.
25、Enhanced Security of Audit Data
Audit records are created in an insert-only tablespace. This new audit tablespace is created as part of the Oracle database infrastructure. The maintenance of the audit trail records are implemented using the audit trail cleanup package that can only be used by users with the new audit administrator role.