1

Unit 9. Lookup Caching, More Features and Techniques

Unit 9

2

Unit Objectives

• Understand when and how to use Persistent Lookup cache

• Use this feature in a mapping

• Practice using more Designer features and techniques

Unit 9

3

Lookup Caching Properties

Persistent cache can improve performance, but stale data may pose a problem

• Lookup caching enabled• Lookup table cached on Server• For relational lookup tables,

performance gain because only one, local SQL SELECT

• Lookup cache persistent• Cache stored on Server hard

drive and used next session unless …

• Re-cache from lookup source• Reload lookup table each

session

Unit 9

4

Unit 9 Lab A Load Promotions Dimension Table

Create a mapping using two Lookup transformations with persistent cache

Create/run a workflow for this mapping

StagingArea

DataWarehouse

STG_PROMOTIONS(table)

DIM_PROMOTIONS(table)

DIM_DATES

Lookups

Unit 9

5

Lab A Review

• What did we accomplish with this lab?

• Questions?

Unit 9

6

Unit 9 Lab B Features and Techniques II

Practice using more Designer features and techniques:• Find in workspace

• View object dependencies

• Comparing objects

• Overview window

Unit 10

7

Lab B Review

• What did we accomplish with this lab?

• Questions?

Unit 10

8

Unit 9 Quiz

When would you use: Lookup cache enabled Persistent lookup cache

Unit 9