Supporting differential views (containing Difference expressions) requires support for negative increments of tuples (negative deltas) for incremental view maintenance. The code explicitly prohibits differential views in database::validate::ViewExpressionValidator.
Supporting differential views (containing
Differenceexpressions) requires support for negative increments of tuples (negative deltas) for incremental view maintenance. The code explicitly prohibits differential views indatabase::validate::ViewExpressionValidator.