Stream Lookup
Options
| Option | Description | 
|---|---|
| Transform name | Name of the transform this name has to be unique in a single pipeline | 
| Lookup Transform | The Transform name where the lookup data is coming from | 
| The keys to lookup… | Allows you to specify the names of the fields that are used to look up values. Values are always searched using the "equal" comparison | 
| Fields to retrieve | You can specify the names of the fields to retrieve here, as well as the default value in case the value was not found or a new field name in case you didn’t like the old one. | 
| Preserve memory | Encodes rows of data to preserve memory while sorting. (Technical background: Hop will store the lookup data as raw bytes in a custom storage object that uses a hashcode of the bytes as the key. More CPU cost related to calculating the hashcode, less memory needed.) | 
| Key and value are exactly one integer field | Preserves memory while executing a sort by . Note: Works only when "Preserve memory" is checked. Cannot be combined with the "Use sorted list" option. | 
| Use sorted list | Enable to store values using a sorted list; this provides better memory usage when working with data sets containing wide row. Note: Works only when "Preserve memory" is checked. Cannot be combined with the "Key and value are exactly one integer field" option. | 
| Get fields | Automatically fills in the names of all the available fields on the source side (A); you can then delete all the fields you don’t want to use for lookup. | 
| Get lookup fields | Automatically inserts the names of all the available fields on the lookup side (B). You can then delete the fields you don’t want to retrieve | 
For guidance on preventing deadlocks when using the Stream Lookup transform, refer to this how-to guide: Avoiding deadlocks