set hive.enforce.bucketing = true; set hive.exec.mode.local.auto=false; set mapred.reduce.tasks = 10; -- This test sets number of mapred tasks to 10 for a database with 50 buckets, -- and uses a post-hook to confirm that 10 tasks were created CREATE TABLE bucket_nr(key int, value string) CLUSTERED BY (key) INTO 50 BUCKETS; set hive.exec.post.hooks=org.apache.hadoop.hive.ql.hooks.VerifyNumReducersHook; set VerifyNumReducersHook.num.reducers=10; insert overwrite table bucket_nr select * from src; set hive.exec.post.hooks=; drop table bucket_nr;