set hive.auto.convert.join = true;

CREATE TABLE dest1(key1 INT, value1 STRING, key2 INT, value2 STRING) STORED AS TEXTFILE;

explain
FROM src src1 JOIN src src2 ON (src1.key = src2.key)
INSERT OVERWRITE TABLE dest1 SELECT src1.*, src2.*;


FROM src src1 JOIN src src2 ON (src1.key = src2.key)
INSERT OVERWRITE TABLE dest1 SELECT src1.*, src2.*;

SELECT sum(hash(dest1.key1,dest1.value1,dest1.key2,dest1.value2)) FROM dest1;