Yahoo has developed a new language called Pig Latin that fit in a sweet spot between high-level declarative querying in the spirit of SQL, and low-level, procedural programming `a la map-reduce and combines best of both worlds.

The accompanying system, Pig, is fully implemented, and compiles Pig Latin into physical plans that are executed over Hadoop, an open-source, map-reduce implementation. Pig has just graduated from the Apache Incubator and joined Hadoop as a subproject.

The paper has a few examples of how engineers at Yahoo! are using Pig to dramatically reduce the time required for the development and execution of their data analysis tasks, compared to
using Hadoop directly.

References: Apache Pig Wiki