Feed forty articles about a rumored plant restart to a summarizer and you get one smooth paragraph: several outlets report that production will resume in March, though the ministry has pushed back. It reads well. It also throws away what you’d need to act on it. You can’t tell which outlets reported it, whether each had its own source or all copied one wire story, or what the ministry actually said, a denial or a polite refusal to comment.

An auditor asks you to show that customer 1187 was screened against a sanctions list on March 3. The screening job writes a row when it finds a match, and customer 1187 has no rows. That fits two histories: the job ran and found nothing, or the job never ran. The database can’t tell them apart, so you hold no evidence either way.

This is the closed-world assumption doing what SQL has always done: a row that doesn’t exist is false. RDF and OWL went the other way with an open-world assumption, where a missing statement means unknown. Neither has a place for the sentence you actually want to store: I looked here, in this way, at this time, and found nothing.