Abstract: In order to deal with the incomplete and contradictory information in data over time, the academia proposes a data model basd on temporal paraconsistent database. Based on this model, this paper preliminary discusses and gives the related properties of relational operators, and according to the established relationship between certain properties of operators the query language is optimized, so as it improves the query speed.

Key words: paraconsistent database, fourvalued logic, temporality, query optimization