hive 影响reduce 个数的参数

[root@hadoop ~]# hive -e "set" | grep reduce

Logging initialized using configuration in jar:file:/usr/hadoop/hive-0.11.0/lib/hive-common-0.11.0.jar!/hive-log4j.properties
Hive history file=/tmp/root/hive_job_log_root_27306@hadoop_201310240233_1629855652.txt
hive.exec.reducers.bytes.per.reducer=1000000000
hive.exec.reducers.max=999
hive.mapred.reduce.tasks.speculative.execution=true
hive.multigroupby.singlereducer=true
hive.optimize.mapjoin.mapreduce=false
hive.optimize.reducededuplication=true
hive.optimize.reducededuplication.min.reducer=4
mapred.reduce.tasks=-1

可以手动设置以上几个参数