Dynamic lookup cache not updating
But your data warehouse table stores the history (may be in the form of SCDType-II).There is a map that loads your data warehouse table from the source table.When the Integration Service creates the dynamic lookup cache, it tracks the range ofvalues in the cache associated with any port using a sequence ID and itgenerates a key for the port by incrementing the greatest sequence ID existingvalue by one, when the inserting a new row of data into the cache.Whenthe Integration Service reaches the maximum number for a generated sequence ID,it starts over at one and increments each sequence ID by one until it reachesthe smallest existing value minus one.The Designer only enables this property for lookup/output ports when theport is not used in the lookup condition.We can improve performance byignoring some ports during comparison.
Whenwe choose to ignore NULLs, we must verify that we output the same values to thetarget that the Integration Service writes to the lookup cache.
The Integration Service uses the data inthe associated port to insert or update rows in the lookup cache.
The Designerassociates the input/output ports with the lookup/output ports used in thelookup condition.
We can Configure the mapping based on the value we want the Integration Service tooutput from the lookup/output ports when it updates a row in the cache, so thatlookup cache and the target table might not become unsynchronized.
Itcompares the values to determine whether or not to update the row in the lookupcache.