DLV is a powerful system for Knowledge Representation and Reasoning which supports Answer Set Programming (ASP) - a logic-based programming paradigm for solving problems in a fully declarative way. DLV is currently widely used in academy, and, importantly, it has been fruitfully employed in many relevant industrial applications. Similarly to the other main-stream ASP systems, while processing an input program, in a first phase of the computation DLV eliminates the variables, thus generating a ground program which is semantically equivalent to the original one, but significantly smaller than the Herbrand Instantiation, in general. This phase, called 'grounding', plays a key role for the successful deployment in real-world contexts. In this work we present I-DLV, a brand new version of the intelligent grounder of DLV. While relying on the solid theoretical foundations of its predecessor, it has been completely redesigned and re-engineered, both in algorithms and data structures; it nowfeatures full support to ASP-Core-2 standard language, increased flexibility and customizability, significantly improved performance, and an extensible design that eases the incorporation of language updates and optimization techniques. I-DLVresults in a stable and efficient ASP instantiator, that turns out to be a full-fledged deductive database system. We describe here the main features of I-DLVand present the results of proper experimental activities for assessing both its applicability and performance.