Queries with Arithmetic on Incomplete Databases
Marco Console, Matthias F. J. Hofer, Leonid O. Libkin · 2020
The standard notion of query answering over incomplete database is that of certain answers, guaranteeing correctness regardless of how incomplete data is interpreted. In majority of real-life databases, relations have numerical columns and queries use arithmetic and comparisons. Even though the notion of certain answers still applies, we explain that it becomes much more problematic in situations when missing data occurs in numerical columns.