I started a full crawl during the day because I created some managed metada columns and needed to have them showing on the search results. After experiencing really slow performance, I stopped it and decided to wait for the overnight full crawl.
For some reason after users started complaining about performance again, I went to the search service application and noted that a full was being run. This left me a bit perplexed, because after double checking, the full is only scheduled to run overnight. Is it possible that the search service application auto starts a full crawl if it is stopped manually?