準備上 11g 了，瞭解下新特性

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          oracle 11g釋出在即，簡單的看了一下11g new feature的介紹，發現有些功能還是比較不錯的，先列一下我目前看到的new feature

1. Use ASM Fast Mirror Resync to improve disk failure recovery times
2. Set up ASM Fast Mirror Resync using SQL
3. Configure preferred mirror groups using the ASM_PREFERRED_READ_FAILURE_GROUPS parameter
4. Use the SYSASM privilege to manage ASM disks
5. Use the compatibility modes for disk groups
6. Use ASMCMD command extensions to back up and restore disk groups
7. Discuss LOB improvements using SecureFiles
8. Use temporary tablespace enhancements
9. Perform. proactive failure checks using the Data Recovery Advisor
10. Enable tracking of table data using Flashback Data Archive
11. Back out data changes using flashback transaction
12. Configure archive log deletion policies
13. Duplicate active databases using Oracle network (without backups)
14. Back up large files in multiple sections
15. Create archival backups for long-term storage
16. Query a physical standby database while redo is applied
17. Control the location of SQL Apply event information
18. Set the retention target for remote archived log files
19. Use the logical standby database flash recovery area
20. Create a snapshot standby database
21. Configure the password file to use case-sensitive passwords
22. Use TDE support on a logical standby database
23. Use TDE support for Streams
24. Create a tablespace with encryption for added security
25. Store external encrypted data using the Hardware Security Module
26. Use LOB encryption for SecureFile LOBs on per-column or per-partition basis
27. Use EM to manage your database security options
28. Set up and modify Automatic SQL Tuning
29. Create AWR Baselines for future time periods
30. Use additional supplied maintenance windows for specific maintenance tasks
31. Simplify memory configuration by setting MEMORY_TARGET initialization parameters
32. Improve file accessibility of the SPFILE file
33. Perform. clusterwide analysis of performance using RAC-aware ADDM
34. Implement partitioning on tables, indexes, and materialized views from SQL Access Advisor’s recommendations
35. Use partitioning enhancements to gain significantly faster data access
36. Gain flexibility in automatic statistic generation at the object level
37. Use memory efficiently with Query Result Cache support
38. Gain execution speed by using automatic native PL/SQL and Java compilation
39. Discuss the increased cursor shareability

這裡列了39項，但實際上還沒公佈的肯定還有很多，從已經公佈的功能來看，我看了功能介紹覺得9，13，16，39還是比較實用。

9.Perform. proactive failure checks using the Data Recovery Advisor

Data Recovery Advisor 這個功能我是比較看中的，透過和EM的整合，資料庫恢復的效率明顯可以提高，從功能介紹的PPT來看，EM不僅能給出錯誤原因，還能給出RMAN恢復指令碼，DBA可以選擇由EM來自動做或者自己手工執行指令碼，把複雜的事情做的越來越易用，oracle這一點我覺得做的非常好，DBA不需要過多的糾纏於各種各樣的命令，當然DBA要知道自己做的操作對資料庫將會有什麼影響，所以對DBA的要求並沒有降低，只是體力勞動減少了。

13.Duplicate active databases using Oracle network (without backups)

 這個功能也不錯，可以線上Duplicate database，這在建立standby database時非常有用，我們不再需要有一份rman備份來做standby database，直接可以從active database來建立standby database，而且em也提供了圖形化的操作，非常簡化整個過程。

16.Query a physical standby database while redo is applied

這個功能每個DBA都在期待，毫無疑問我會為它歡呼。我們一下子就有了最穩定的同步方案，要實現多站點讀寫分開的公司有福了！

39.Discuss the increased cursor shareability

這個功能和上述幾個功能比起來不是那麼顯眼，不過我覺得還是有一定價值的。大家都知道以前oracle的bind peeking有個缺陷就是它只會在第一次解析的時候做一個peeking，後續的bind value他就不管了，11g的這個新功能推出以後就不會有這種事情了，oracle會根據bind value的selectivity來看是share cursor還是reparse。