Wednesday 22 August 2012

Difference between two versions

Difference between 9i and 10g:


9i and 10g:-
Differences:
Ø  Major changes to SQL optimizer internals.
Ø  ‘DataPump’ replaces ‘imp’ utility with ‘impdp’.
Ø  Oracle grid computing.
Ø  AWR (Automatic Workload Repository) and ASH(Automatic Storage Management) tables incorporated into oracle performance pack and Diagnostic pack options.
Ø  Automatic Database Diagnostic Monitor (ADDM).
Ø  SQL tuning Advisor.
Ø  SQL Access Advisor.
Ø  Rolling Database upgrades (using oracle 10g RAC)
Ø  Dbms_scheduler package replaces dbms_job for scheduling.
Ø  Automated Session History (ASH) materializes the oracle wait interface over time.
Features:
·         Web Server Load Balancing:  The web cache component includes Apache extension to load-balance transactions to the least-highly-loaded Oracle HTTP server (OHS).
·         Automated Storage Load Balancing: Oracle’s Automatic Storage Management (ASM) now enables a single storage pool to be shared by multiple databases for optimal load balancing.  Shared disk storage resources can alternatively be assigned to individual databases and easily moved from one database to another as processing requirements change.
·        Data Guard Load Balancing: Oracle Dataguard allows for load balancing between standby databases.
·        Listener Load Balancing: If advanced features such as load balancing and automatic failover are desired, there are optional sections of the listener.ora file that must be present.  Automatic Storage Management (ASM) includes multiple disk operations and a non-ASM database migration utility
·        Enhancements to data provisioning and Oracle Streams designed to make it easier to archive, move, and copy large data sets
·        New Fast-Start Failover for automatic fail over to standby databases
·        Integrated data encryption and key management in the database
·        Automated statistics collection directly from memory designed to eliminate the need to execute SQL queries
·        New administrative reports include automatic database workload repository comparison
·        Extended use of Standard Chunk sizes - In 10gR2, the server has been enhanced to further leverage standard chunk allocation sizes. This additional improvement reduces the number of problems arising from memory fragmentation.
·        Mutexes - To improve cursor execution and also hard parsing, a new memory serialization mechanism has been created in 10gR2. For certain shared-cursor related operations, mutexes are used as a replacement for library cache latches and librarycache pins. Using mutexes is faster, uses less CPU and also allows significantly improved concurrency over the existing latch mechanism. The use of mutexes for cursor pins can be enabled by setting the init.ora parameter _use_kks_mutex to TRUE.

Views:-
§  V$SGASTAT - V$SGASTAT has been enhanced to display a finer granularity of memory to component allocation within the shared pool. This allows faster diagnosis of memory usage (in prior releases many smaller allocations were grouped under the ‘miscellaneous’ heading).
§  V$SQLSTAT - A new view, V$SQLSTAT has been introduced which contains SQL related statistics (such as CPU time, elapsed time, sharable memory). This view is very cheap to query even on high-concurrency systems, as it does not require librarycache latch use. It contains the most frequently used SQL statistics in the V$SQL family of views.
§  V$OPEN_CURSOR - This implementation of this view has also been enhanced to be latchless, making it inexpensive to query.
§  V$SQLAREA - The V$SQLAREA view has been improved in 10gR2; the view optimizes the aggregation of the SQL statements while generating the view data.

Miscellaneous Oracle10g enhancements:
·         Introduced RECYCLEBIN command for storing objects before they are dropped. Required new PURGE command for maintenance.
·         sqlplus / as sysdba accessibility without quote marks
·         SYSAUX tablespace
·         Multiple Temporary Tablespaces supported to reduce stress on sorting in TEMP
·         RMAN introduces compression for backups
·         New drop database syntax
·         New alter database begin backup syntax
·         Oracle10g Data Guard Broker introduced
·         Oracle10g RAC supports secure Redo Log transport
·         Flashback enhancements for flashback database and flashback table syntax
·         VPD (FGAC, RLS) supports both row-level and column-level VPD
Simply Telling:

Ø  Transparent Data Encryption 
Ø  Async commits 
Ø  CONNECT ROLE can not only connect 
Ø  Passwords for DB Links are encrypted 
Ø  New asmcmd utility for managing ASM storage 
Ø  Grid computing - an extension of the clustering feature (RealApplication Clusters) 
Ø  Manageability improvements (self-tuning features) 
Ø  Performance and scalability improvements 
Ø  Automated Storage Management (ASM) 
Ø  Automatic Workload Repository (AWR) 
Ø  Automatic Database Diagnostic Monitor (ADDM) 
Ø  Flashback operations available on row, transaction, table or database level 
Ø  Ability to UNDROP a table from a recycle bin 
Ø  Ability to rename tablespaces 
Ø  Ability to transport tablespaces across machine types (E.g Windows to Unix)
New 'drop database' statement
New database scheduler - DBMS_SCHEDULER
Ø  DBMS_FILE_TRANSFER Package 
Ø  Support for bigfile tablespaces that is up to 8 Exabytes in size 
Data Pump - faster data movement with expdp and impdp