By default, the database uses deferred segment creation to update only database metadata when creating tables and indexes. Starting in Oracle Database 11g Release 2 (11.2.0.2), the database also defers segment creation when creating partitions. When a user inserts the first row into a table or partition, the database creates segments for the table or partition, its LOB columns, and its indexes.


When Database Smart Flash Cache (flash cache) is enabled, part of the buffer cache can reside in the flash cache. This buffer cache extension is stored on aflash disk device, which is a solid state storage device that uses flash memory. The database can improve performance by caching buffers in flash memory instead of reading from magnetic disk.
Note:Database Smart Flash Cache is available only in Solaris and Oracle Enterprise Linux.

在11g以及之后的版本，都不建议CURSOR_SHARING=SIMILAR，在12g，该参数将被弃用。
http://www.oracledatabase12g.com/archives/cursor_sharing-similar%E5%B0%86%E8%A2%AB%E5%BA%9F%E5%BC%83.html

Automatic Block Repair
The enhancements to corrupt block detection make block repair more efficient and increase availability. The automatic block repair enhancement complements the Oracle Database 11g Release 1 automatic block corruption detection.
A detected corrupt block (for example, via a user's SQL query) is now automatically repaired by using a good block from a physical standby database. With automatic block repair, a user querying data in the corrupt block no longer sees the corrupt block error message displayed (ORA-01578). Instead, there is a pause while the corrupt block is repaired, and then the results of the SQL query are returned. The automatic block repair is transparent to the user unless the repair fails. Block recovery is faster because no redo needs to be applied to the block that is taken from the physical standby database.
Automatic block repair requires an Oracle Active Data Guard license because real-time query mode must be enabled on the physical standby database.
The operation occurs automatically but can also be explicitly invoked with the RMAN RECOVER BLOCK
~~~~~
SET NEWNAME
RUN{ SET NEWNAME FOR DATABASE TO '/oradata/%U'; DUPLICATE TARGET DATABASE TO dupdb SKIP TABLESPACE tools LOGFILE GROUP 1 ('/duplogs/redo01a.log', '/duplogs/redo01b.log') SIZE 4M REUSE, GROUP 2 ('/duplogs/redo02a.log', '/duplogs/redo02b.log') SIZE 4M REUSE;}
RUN{ SET NEWNAME FOR TABLESPACE users TO '/oradata%f/%b'; SET NEWNAME FOR DATAFILE 1 TO '/oradata1/system01.dbf'; SET NEWNAME FOR DATAFILE 2 TO '/oradata2/sysaux01.dbf'; SET NEWNAME FOR DATAFILE 3 TO '/oradata3/undotbs01.dbf'; SET NEWNAME FOR TEMPFILE 1 TO '/oradatat/temp01.dbf'; DUPLICATE TARGET DATABASE TO dupdb SKIP TABLESPACE tools LOGFILE GROUP 1 ('/duplogs/redo01a.log', '/duplogs/redo01b.log') SIZE 4M REUSE, GROUP 2 ('/duplogs/redo02a.log', '/duplogs/redo02b.log') SIZE 4M REUSE;}
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10g 之后：
CONVERT TABLESPACE/ DATAFILE/ DATABASE
跨平台迁移。
~~~~~~~~~~~~~~~~11g RMAN 的压缩特性：
RMAN uses two types of block compression when creating backup sets:
Unused Block Compression (Supports disk backup and Oracle Secure Backup tape backup)
Null Block Compression (Supports all backups)
Although it is referred to as block compression, it might be helpful to think of block compression as block skipping. Rather than compressing the data in the blocks, RMAN completely eliminates the blocks from the backup. RMAN reads blocks from a datafile and writes them to a backup set. If unused block compression is enabled, RMAN reads only those blocks of the datafile in an extent that currently belongs to a database segment. Unused block compression can only be employed when backing up tablespaces whose space is locally managed. When not employing unused block compression, RMAN reads every block of the datafile. Before RMAN writes a block to the backup set, it applies the null block test, and if the block has never been used, it does not write that block to the backup set.
Unused Block Compression 对于那些数据文件巨大，但是真实数据量不大的数据库较为有效。
Unused Block Compression 基本是自动开启的：
Unused block compression is turned on automatically when all of the following five conditions are true:
The COMPATIBLE initialization parameter is set to 10.2 or higher.There are currently no guaranteed restore points defined for the database.The datafile is locally managed.The datafile is being backed up to a backup set as part of a full backup or a level 0 incremental backup.The backup set is created on disk, or cure Backup is the media manager.
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