Introduction to DAC
1) DAC provides a framework for the entire life cycle of data warehouse
2) It enables you to create, configure, execute, and monitor modular data warehouse applications in a parallel, high-performing environment.
3) For information about the DAC process life cycle, see "About the DAC Process Life Cycle".
4) DAC complements the Informatica ETL platform.
5) It provides application-specific capabilities that are not prebuilt into ETL platforms.
6) For example, ETL platforms are not aware of the semantics of the subject areas being populated in the data warehouse nor the method in which they are populated.
DAC provides the following application capabilities at a layer of abstraction above the ETL execution platform:
1. Dynamic generation of subject areas and execution plans
2. Dynamic settings for parallelism and load balancing
3. Intelligent task queue engine based on user- defined and computed scores Automatic full and incremental mode aware
4. Index management for ETL and query performance
5. Embedded high performance Siebel OLTP change capture techniques
6. Ability to restart at any point of failure
7. Phase-based analysis tools for isolating ETL bottlenecks
Important DAC Features
Important DAC features enable you to do the following:
Minimize installation, setup, and configuration time
1. Create a physical data model in the data warehouse
2. Set language, currency, and other settings
3. Design subject areas and build execution plans
Manage metadata driven dependencies and relationships
4. Generate custom ETL execution plans
5. Automate change capture for the Siebel transactional database
6. Capture deleted records
7. Assist in index management
8. Perform dry runs and test runs of execution plans
Provide reporting and monitoring to isolate bottlenecks
10. Perform error monitoring and email alerting
11. Perform structured ETL analysis and reporting
Utilize performance execution techniques
12. Automate full and incremental mode optimization rules
13. Set the level of Informatica session concurrency
14. Load balance across multiple Informatica servers
15. Restart from point of failure
16. Queue execution tasks for performance (See Figure 3–1.)
17. DAC manages the task execution queue based on metadata driven priorities and scores computed at runtime. This combination allows for flexible and optimized execution. Tasks are dynamically assigned a priority based on their number of dependents, number of sources, and average duration.