On the Power of Incremental Evaluation in SQL-Like Languages
نویسندگان
چکیده
We consider IES(SQL), the incremental evaluation system over an SQL-like language with grouping, arithmetics, and aggregation. We show that every second order query is in IES(SQL) and that there are PSPACE-complete queries in IES(SQL). We further show that every PSPACE query is in IES(SQL) augmented with a deterministic transitive closure operator. Lastly, we consider ordered databases and provide a complete analysis of a hierarchy on IES(SQL) deened with respect to arity-bounded auxiliary relations.
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