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when does the dynamic lookup cache is updated?

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can somebody explain to me when does the dynamic lookup cache file is updated?

is it when the lookup transform is done or when the row source to target path has ended?

posted Aug 5, 2014 by Sunil

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1 Answer

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A dynamic lookup cache is updated whenever a lookup is done to it. The Integration Service will alter the cache if necessary when it is processing a Lookup transformation that has dynamic caching enabled.

If the lookup fails, i.e. the incoming port values were not found in the cache, then they are added to it at that point (depending on how the transformation is configured), and the Integration Service continues processing downstream transformations.

This means that downstream transformations in the mapping as well as any further rows that are processed through the mapping should be able to "see" the new cache record when the Lookup has been processed for the current row.

answer Aug 7, 2014 by Shweta Singh
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Using Informatica 9.1.0

Scenario

Get the Dimension key generated and inserted to the Fact table from the Fact load.

I have to load the Fact table with a dimension key along with other columns. This dimension record is created from within the same mapping. There are five different sessions using the same mapping and executes simultaneously to load the Fact table. In this case I'm using a dynamic lookup with 'Synchronize dynamic cache' enabled to get unique dimension records generated from the 5 sessions using some conditions. The dimension ID is generated using the Sequence-ID in associated expression of the lookup. When a single session alone is run it worked perfectly fine. But when the sessions were run parallely it started to show unique key violation error as random sessions tried to insert the same sequence which was already there.

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Thanks in advance

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What are the different lookup cache(s)?

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