A Lookup is a Passive, Connected or Unconnected Transformation used to look up data in a relational table, view, synonym or flat file. The integration service queries the lookup table to retrieve a value based on the input source value and the lookup condition.
A connected lookup recieves source data, performs a lookup and returns data to the pipeline;
While an unconnected lookup is not connected to source or target and is called by a transformation in the pipeline by :LKP expression which in turn returns only one column value to the calling transformation.
Lookup can be Cached or Uncached. If we cache the lookup then again we can further go for static or dynamic or persistent cache,named cache or unnamed cache .
A connected lookup recieves source data, performs a lookup and returns data to the pipeline;
While an unconnected lookup is not connected to source or target and is called by a transformation in the pipeline by :LKP expression which in turn returns only one column value to the calling transformation.
Lookup can be Cached or Uncached. If we cache the lookup then again we can further go for static or dynamic or persistent cache,named cache or unnamed cache .