Research on Soft Set Theory and Parameters Reduction Based on Relational Algebra

This paper, based on relational algebra theory, defines difference operation, selection operation and projection operation in soft set theory, applies several basic operations of relational algebra including selection, projection, union and difference to describe the algorithm of parameters reduction of a soft set based on invariability of the optimal choice object, and proves the feasibility of this algorithm of parameters reduction. At last, this algorithm mentioned above is realized using SQL.