Is the Chronus query language compatible with standard SQL?
In principle, yes. The Chronus temporal query language is a strict superset of the SQL89 grammar. Thus, it accepts all standard SQL89 queries and works without modification on standard relational databases. The Chronus query language does not fully support many SQL92 features, but neither does any DBMS that we are aware of. The grammar used as the basis of the Chronus parser is based on the variabnt of SQL supported by Oracle 7. The BNF for this grammar can be found here.