Why do I need to use DAC from Oracle BI?

DAC的作用：http://www.google.com.hk/url?sa=t&rct=j&q=DAC+informatica&source=web&cd=2&ved=0CHMQFjAB&url=http%3A%2F%2Fdylanwan.wordpress.com%2F2007%2F01%2F08%2Fwhy-do-i-need-to-use-dac%2F&ei=uvznT7nzG_CaiAfJ3Z1a&usg=AFQjCNHcNw43p8owp_EA1QaoZQ-wzCAPJg

 

 

Data Warehouse Application Console (DAC) works together with Informatica to acomplish the ETL for pre-packaged BI applications.

Here are what happen behind the scene:

• DAC publish the changes from OLTP
• Informatica extracts the changes from the change log published by DAC as well as from the base table
• Informatica load the data to the stage tables and the target tables in the data warehouse
• DAC manage the performance by dropping indexes, truncating stage tables, rebuilding the indexes, and analyzing the tables during the process

If you do not use DAC, you have to write your own custom change capture process and need to redesign from scratch an ETL method that allow the restart of the ETL process from point of failure at record level. The biggest saving is that DAC can survive during the upgrade , while your custom processes cannot.

如上一篇文章所述，脫離了DAC之後，很多東西，包括增量、ETL_PROC_WID等都需要自己再做客戶化，修修改改的地方比較多。

近期會比較關注BI、DW、informatica方面的內容