Relational Database Access for an Algebraic Modeling Language

The description of data in algebraic modeling languages is well known to have useful parallels to the organization of data in relational databases. We describe new features of the AMPL modeling language that take advantage of these parallels to facilitate exchanges of information between optimization models and database files. Our emphasis is on features that differ from those of existing modeling language database links. A system of modular "handlers" enables vendors or developers to add database connections without modifying the core AMPL code. Various input and output modes provide flexibility in how data representations are converted between AMPL and relational tables.