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Monday, March 18, 2013

Rules and Guidelines for Dynamic Caches


The Lookup transformation must be a connected transformation.
1. You can use a persistent or a non-persistent cache.
2. If the dynamic cache is not persistent, the Informatica Server always rebuilds the cache from the database, even if you do not enable Recache from Database.
3. You cannot share the cache between a dynamic Lookup transformation and static Lookup transformation in the same target load order group.
4. You can only create an equality lookup condition. You cannot look up a range of data.
5. Associate each lookup port (that is not in the lookup condition) with an input port or a sequence ID.
6. Only connect lookup/output ports to the target table instead of input/output ports. When you do this, the Informatica Server writes the same values to the lookup cache and the target table, keeping them synchronized.
7. When you use a lookup SQL override, make sure you map the correct columns to the appropriate targets for lookup.
8. When you add a WHERE clause to the lookup SQL override, use a Filter transformation before the Lookup transformation. This ensures the Informatica Server only inserts rows in the dynamic cache and target table that match the WHERE clause. For details, see Using the WHERE Clause with a Dynamic Cache.
9. When you configure a reusable Lookup transformation to use a dynamic cache, you cannot edit the condition or disable the Dynamic Lookup Cache property in a mapping.
10. Use Update Strategy transformations after the Lookup transformation to flag the rows for insert or update for the target.
11. Use an Update Strategy transformation before the Lookup transformation to define some or all rows as update if you want to use the Update Else Insert property in the Lookup transformation.
12. Set the row type to Data Driven in the session properties.
13. Select Insert and Update as Update for the target table options in the session properties.

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