Database Reference
In-Depth Information
Building the cache - sequential or concurrent
You can define the session property to create the cache either sequentially or concurrently.
Sequential cache
When you choose to create the cache sequentially, Integration Service caches the data in a
row-wise manner as the records enter the Lookup transformation. When the first record
enters the Lookup transformation, the lookup cache gets created and stores the matching re-
cord from the lookup table or file in the cache. This way, the cache stores only matching
data. This helps save the cache space by not storing the unnecessary data.
Concurrent cache
When you choose to create caches concurrently, Integration Service does not wait for the
data to flow from the source, but it first caches the complete data. Once the caching is com-
plete, it allows the data to flow from the source. When you select concurrent cache, per-
formance is better than sequential caches, as the scanning happens internally using the data
stored in cache.
