Automatic Diagnostic Repository.
ADR is file based repository for diagnostic data like trace file,process dump,data structure dump etc. In oracle 11g trace. alert not saved in *_DUMP_DEST directory even you set those parameters in init.ora.11g ignore *_DUMP_DEST and store data in new format.

New initialize parameter DIAGNOSTIC_DEST decide location of ADR root,

Database Capture/replay database workloads :-
Allows the total database workload to be captured, transferred to a test database created from a backup or standby database, then replayed to test the affects of an upgrade or system change. Currently, they are working to a capture performance overhead of 5%, so you could conceivably capture real production workloads.

Automatic Memory Tuning:-
Automatic PGA tuning was introduced in Oracle 9i.
Automatic SGA tuning was introduced in Oracle 10g.
In 11g, all memory can be tuned automatically by setting one parameter. You literally tell Oracle how much memory it has and it determines how much to use for PGA, SGA and OS Processes. Maximum and minimum thresholds can be set.
We need to set parameter MEMORY_TARGET and MEMORY_MAX_TARGET where are sga_target and pga_aggregated_target should be zero

Database Health Check:-
Oracle introducee a new feature in 11g for monitoring the database health named as health monitor. With health monitor oracle automatically run a diagnostic operation to check any database corruption or error.

Data Recovery Advisor:-
Data Recovery Advisor is an Oracle Database 11g tool that automatically diagnoses data failures, determines and presents appropriate repair options, and executes repairs at the user’s request. Data Recovery Advisor can diagnose failures such as the following:
Inaccessible components like datafiles and control files.
Physical corruptions such as block checksum failures and invalid block header
Field values,Inconsistent datafiles (online and offline)
I/O failures
The advisor however doe not recover from failures on standby databases or RAC environment. This advisor can be used through RMAN or the Enterprise Manager.

Oracle Flashback-Related New Features
Oracle Database 11g introduces the following new Flashback-related features:
LogMiner Interface in Oracle Enterprise Manager
•Oracle Flashback Transaction Backout
•Oracle Flashback Data Archives

Case sensitive password :-
In 11g Passwords are case sensitive by default, new init.ora parameter sec_case_sensitive_logon is introduce in 11g . it values could be.
sec_case_sensitive_logon = (TRUE FALSE)
On system level you can switch off
alter system set sec_case_sensitive_logon = false
Find users who have case sensitive or case insensitive passwords

SQL> SELECT USERNAME,PASSWORD_VERSIONS FROM DBA_USERS — Password file orapwd file=orclpwd password=manager ignorecase=y

SQL Performance Analyzer (SPA):-                                                                                                                                                                 It is a new feature in 11g. The SPA is used to measure the performance of SQL statement execution impact due to changes in database. If it find out the degradation in one or more sql sttmts performance then it will give recommendations on how to improve their performance.

Active Database Duplication
Now DUPLICATE command is network aware i.e.we can create a duplicate or standby database over the network without taking backup or using old backup.

RMAN UNDO bypass : Rman backup can bypass undo. Undo tablespaces are getting huge, but contain lots of useless information. Now rman can bypass those types of tablespaces
Fast incremental backups on physical standby database in 11g we can enable block change tracking on a physical standby database (ALTER DATABASE ENABLE/ DISABLE BLOCK CHANGE TRACKING SQL statement).This new 11g feature enables faster incremental backups on a physical standby database than in previous releases. because RMAN identify the changed blocks since the last incremental backup.

Improved block media recovery performance:-
RECOVER command can recover individual data blocks.
RMAN take older, uncorrupted blocks from flashback and the RMAN can use these blocks, thereby speeding up block media recovery.

ADDM RAC Enhancements:-
In case of RAC script addmrpt.sqlrun give report for single instance, not report of all instance in RAC. But using DBMS_ADDM , we can generate report for all instance of RAC.