Database Reference
In-Depth Information
Modifying cache - static or dynamic
When you create a cache, you can configure it to be static or dynamic.
Static cache
A cache is said to be static if it does not change with the changes happening in the lookup
table. A static cache is not synchronized with the lookup table.
By default, Integration Service creates a static cache. A lookup cache is created as soon as
the first record enters the Lookup transformation. Integration Service does not update the
cache while it is processing the data.
Dynamic cache
A cache is said to be dynamic if it changes with the changes happening in the lookup table.
The dynamic cache is synchronized with the lookup table.
From the Lookup transformation properties, you can choose to make the cache dynamic.
The lookup cache is created as soon as the first record enters the Lookup transformation.
Integration Service keeps on updating the cache while it is processing the data. It marks the
record INSERT for new rows inserted in dynamic cache. For the record that is updated, it
marks the record as updated in the cache. For every record that doesn't change, Integration
Service marks it as unchanged.
You use the dynamic cache while you process slowly changing dimension tables. For every
record inserted into the target, the record will be inserted in the cache. For every record up-
dated in the target, the record will be updated in the cache. A similar process happens for
the deleted and rejected records.
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