《PC9xL1D_Mod_11_WorkflowVariables_v3》.ppt

Module 11: Workflow Variables, Incremental Aggregation and Tasks 11.10 Still not very realistic. You could actually just base the decision on link conditions. But it gets the idea across. Module 11: Workflow Variables, Incremental Aggregation and Tasks 11.11 Purpose: Place the “teaching point” of the slide here “Purpose” should be on every slide; use the following as needed/appropriate Steps: Things to do when teaching this slide (explanations, suggested demos, etc.) Questions: Questions to ask the students to get ‘em thinking FAQs: Things the students are likely to ask Technical info: Detailed explanations for students who need that sort of thing INFA-internal information should be indicated clearly as such so instructors know not to give it in customer teaches 11 Module 11: Workflow Variables, Incremental Aggregation and Tasks 11.12 Consider using incremental aggregation in the following circumstances: When you can capture new source data each time you run the session. Use a Stored Procedure or Filter transformation to process new data. When the changes do not significantly change the target. If processing the incrementally changed source alters more than half the existing target, the session may not benefit from using incremental aggregation. In this case, drop the table and recreate the target with complete source data. Module 11: Workflow Variables, Incremental Aggregation and Tasks 11.13 The first time you run an incremental aggregation session, the Integration Service processes the entire source. At the end of the session, the Integration Service stores aggregate data from that session run in two files, the index file and the data file. Each subsequent time you run a session with incremental aggregation, the IS creates a backup of the incremental aggregation files. The cache directory for the Aggregator transformation must contain enough disk space for two sets of the files. When you partition a session that uses incremental aggregation, the IS crea