Lookup nodes

Lookup nodes take one stream and add columns to each row, answered by a system outside the pipeline through a connection. API Lookup calls a web API once per row, API Batch Lookup sends it many rows at a time, and Database Lookup fetches only the keys you have from a database table, so a big table is never read whole. When no built-in node fits, put your own code behind an HTTPS endpoint and API Batch Lookup or API Lookup calls it. To combine two streams that are already on the canvas, use a Join node.