How to force STORE (overwrite) to HDFS in Pig?

问题：

 Pig Grunt 中，fs -rmr /apps/hive/warehouse/tmp_test 可以正常运行

直接运行pig -param_file/home/hive/sample.params /home/hive/preprocess.pig ，如果已经有/apps/hive/warehouse/tmp_test 文件存在，会报错；

2012-06-19 19:22:49,680 [main] ERROR org.apache.pig.tools.grunt.Grunt - ERROR 6000: Output Location Validation Failed for: 'hdfs://[server]/user/[user]/foo/bar More info to follow:Output directory hdfs://[server]/user/[user]/foo/bar already exists

解决方案：

http://stackoverflow.com/questions/11110403/how-to-force-store-overwrite-to-hdfs-in-pig

rmf foo/bar