Pig, 谁来试试？

zouquan

http://pig.apache.org/

Pig is a high-level data-flow language (Pig Latin) and execution framework whose compiler produces sequences of Map/Reduce programs for execution within Hadoop. Pig is designed for batch processing of data. Pig’s infrastructure layer consists of a compiler that turns (relatively short) Pig Latin programs into sequences of MapReduce programs. Pig is a Java clientside application, and users install locally – nothing is altered on the Hadoop cluster itself. Grunt is the Pig interactive shell.

Apache Pig is a platform for analyzing large data sets that consists of a high-level language for expressing data analysis programs, coupled with infrastructure for evaluating these programs. The salient property of Pig programs is that their structure is amenable to substantial parallelization, which in turns enables them to handle very large data sets.

At the present time, Pig's infrastructure layer consists of a compiler that produces sequences of Map-Reduce programs, for which large-scale parallel implementations already exist (e.g., the Hadoop subproject). Pig's language layer currently consists of a textual language called Pig Latin, which has the following key properties:

• Ease of programming. It is trivial to achieve parallel execution of simple, "embarrassingly parallel" data analysis tasks. Complex tasks comprised of multiple interrelated data transformations are explicitly encoded as data flow sequences, making them easy to write, understand, and maintain.
• Optimization opportunities. The way in which tasks are encoded permits the system to optimize their execution automatically, allowing the user to focus on semantics rather than efficiency.
• Extensibility. Users can create their own functions to do special-purpose processing.