Databricks Certified Data Engineer Professional DATA-ENGINEER-PROFESSIONAL — Question 80

A data engineer wants to join a stream of advertisement impressions (when an ad was shown) with another stream of user clicks on advertisements to correlate when impressions led to monetizable clicks. In the code below, Impressions is a streaming DataFrame with a watermark ("event_time", "10 minutes") The data engineer notices the query slowing down significantly. Which solution would improve the performance?