PREHOOK: query: CREATE TABLE srcbucket_mapjoin_part (key int, value string) partitioned by (ds string) CLUSTERED BY (key) INTO 3 BUCKETS STORED AS TEXTFILE PREHOOK: type: CREATETABLE POSTHOOK: query: CREATE TABLE srcbucket_mapjoin_part (key int, value string) partitioned by (ds string) CLUSTERED BY (key) INTO 3 BUCKETS STORED AS TEXTFILE POSTHOOK: type: CREATETABLE POSTHOOK: Output: default@srcbucket_mapjoin_part PREHOOK: query: load data local inpath '../data/files/srcbucket20.txt' INTO TABLE srcbucket_mapjoin_part partition(ds='2008-04-08') PREHOOK: type: LOAD PREHOOK: Output: default@srcbucket_mapjoin_part POSTHOOK: query: load data local inpath '../data/files/srcbucket20.txt' INTO TABLE srcbucket_mapjoin_part partition(ds='2008-04-08') POSTHOOK: type: LOAD POSTHOOK: Output: default@srcbucket_mapjoin_part POSTHOOK: Output: default@srcbucket_mapjoin_part@ds=2008-04-08 PREHOOK: query: load data local inpath '../data/files/srcbucket21.txt' INTO TABLE srcbucket_mapjoin_part partition(ds='2008-04-08') PREHOOK: type: LOAD PREHOOK: Output: default@srcbucket_mapjoin_part@ds=2008-04-08 POSTHOOK: query: load data local inpath '../data/files/srcbucket21.txt' INTO TABLE srcbucket_mapjoin_part partition(ds='2008-04-08') POSTHOOK: type: LOAD POSTHOOK: Output: default@srcbucket_mapjoin_part@ds=2008-04-08 PREHOOK: query: load data local inpath '../data/files/srcbucket22.txt' INTO TABLE srcbucket_mapjoin_part partition(ds='2008-04-08') PREHOOK: type: LOAD PREHOOK: Output: default@srcbucket_mapjoin_part@ds=2008-04-08 POSTHOOK: query: load data local inpath '../data/files/srcbucket22.txt' INTO TABLE srcbucket_mapjoin_part partition(ds='2008-04-08') POSTHOOK: type: LOAD POSTHOOK: Output: default@srcbucket_mapjoin_part@ds=2008-04-08 PREHOOK: query: CREATE TABLE srcbucket_mapjoin_part_2 (key int, value string) partitioned by (ds string) CLUSTERED BY (key) INTO 2 BUCKETS STORED AS TEXTFILE PREHOOK: type: CREATETABLE POSTHOOK: query: CREATE TABLE srcbucket_mapjoin_part_2 (key int, value string) partitioned by (ds string) CLUSTERED BY (key) INTO 2 BUCKETS STORED AS TEXTFILE POSTHOOK: type: CREATETABLE POSTHOOK: Output: default@srcbucket_mapjoin_part_2 PREHOOK: query: load data local inpath '../data/files/srcbucket22.txt' INTO TABLE srcbucket_mapjoin_part_2 partition(ds='2008-04-08') PREHOOK: type: LOAD PREHOOK: Output: default@srcbucket_mapjoin_part_2 POSTHOOK: query: load data local inpath '../data/files/srcbucket22.txt' INTO TABLE srcbucket_mapjoin_part_2 partition(ds='2008-04-08') POSTHOOK: type: LOAD POSTHOOK: Output: default@srcbucket_mapjoin_part_2 POSTHOOK: Output: default@srcbucket_mapjoin_part_2@ds=2008-04-08 PREHOOK: query: load data local inpath '../data/files/srcbucket23.txt' INTO TABLE srcbucket_mapjoin_part_2 partition(ds='2008-04-08') PREHOOK: type: LOAD PREHOOK: Output: default@srcbucket_mapjoin_part_2@ds=2008-04-08 POSTHOOK: query: load data local inpath '../data/files/srcbucket23.txt' INTO TABLE srcbucket_mapjoin_part_2 partition(ds='2008-04-08') POSTHOOK: type: LOAD POSTHOOK: Output: default@srcbucket_mapjoin_part_2@ds=2008-04-08 PREHOOK: query: -- The number of buckets in the 2 tables above (being joined later) dont match. -- Throw an error if the user requested a bucketed mapjoin to be enforced. -- In the default case (hive.enforce.bucketmapjoin=false), the query succeeds -- even though mapjoin is not being performed explain select a.key, a.value, b.value from srcbucket_mapjoin_part a join srcbucket_mapjoin_part_2 b on a.key=b.key and a.ds="2008-04-08" and b.ds="2008-04-08" PREHOOK: type: QUERY POSTHOOK: query: -- The number of buckets in the 2 tables above (being joined later) dont match. -- Throw an error if the user requested a bucketed mapjoin to be enforced. -- In the default case (hive.enforce.bucketmapjoin=false), the query succeeds -- even though mapjoin is not being performed explain select a.key, a.value, b.value from srcbucket_mapjoin_part a join srcbucket_mapjoin_part_2 b on a.key=b.key and a.ds="2008-04-08" and b.ds="2008-04-08" POSTHOOK: type: QUERY ABSTRACT SYNTAX TREE: (TOK_QUERY (TOK_FROM (TOK_JOIN (TOK_TABREF (TOK_TABNAME srcbucket_mapjoin_part) a) (TOK_TABREF (TOK_TABNAME srcbucket_mapjoin_part_2) b) (and (and (= (. (TOK_TABLE_OR_COL a) key) (. (TOK_TABLE_OR_COL b) key)) (= (. (TOK_TABLE_OR_COL a) ds) "2008-04-08")) (= (. (TOK_TABLE_OR_COL b) ds) "2008-04-08")))) (TOK_INSERT (TOK_DESTINATION (TOK_DIR TOK_TMP_FILE)) (TOK_SELECT (TOK_SELEXPR (. (TOK_TABLE_OR_COL a) key)) (TOK_SELEXPR (. (TOK_TABLE_OR_COL a) value)) (TOK_SELEXPR (. (TOK_TABLE_OR_COL b) value))))) STAGE DEPENDENCIES: Stage-1 is a root stage Stage-0 is a root stage STAGE PLANS: Stage: Stage-1 Map Reduce Alias -> Map Operator Tree: a TableScan alias: a Reduce Output Operator key expressions: expr: key type: int sort order: + Map-reduce partition columns: expr: key type: int tag: 0 value expressions: expr: key type: int expr: value type: string b TableScan alias: b Reduce Output Operator key expressions: expr: key type: int sort order: + Map-reduce partition columns: expr: key type: int tag: 1 value expressions: expr: value type: string Reduce Operator Tree: Join Operator condition map: Inner Join 0 to 1 condition expressions: 0 {VALUE._col0} {VALUE._col1} 1 {VALUE._col1} handleSkewJoin: false outputColumnNames: _col0, _col1, _col6 Select Operator expressions: expr: _col0 type: int expr: _col1 type: string expr: _col6 type: string outputColumnNames: _col0, _col1, _col2 File Output Operator compressed: false GlobalTableId: 0 table: input format: org.apache.hadoop.mapred.TextInputFormat output format: org.apache.hadoop.hive.ql.io.HiveIgnoreKeyTextOutputFormat Stage: Stage-0 Fetch Operator limit: -1 PREHOOK: query: explain select /*+mapjoin(b)*/ a.key, a.value, b.value from srcbucket_mapjoin_part a join srcbucket_mapjoin_part_2 b on a.key=b.key and a.ds="2008-04-08" and b.ds="2008-04-08" PREHOOK: type: QUERY POSTHOOK: query: explain select /*+mapjoin(b)*/ a.key, a.value, b.value from srcbucket_mapjoin_part a join srcbucket_mapjoin_part_2 b on a.key=b.key and a.ds="2008-04-08" and b.ds="2008-04-08" POSTHOOK: type: QUERY ABSTRACT SYNTAX TREE: (TOK_QUERY (TOK_FROM (TOK_JOIN (TOK_TABREF (TOK_TABNAME srcbucket_mapjoin_part) a) (TOK_TABREF (TOK_TABNAME srcbucket_mapjoin_part_2) b) (and (and (= (. (TOK_TABLE_OR_COL a) key) (. (TOK_TABLE_OR_COL b) key)) (= (. (TOK_TABLE_OR_COL a) ds) "2008-04-08")) (= (. (TOK_TABLE_OR_COL b) ds) "2008-04-08")))) (TOK_INSERT (TOK_DESTINATION (TOK_DIR TOK_TMP_FILE)) (TOK_SELECT (TOK_HINTLIST (TOK_HINT TOK_MAPJOIN (TOK_HINTARGLIST b))) (TOK_SELEXPR (. (TOK_TABLE_OR_COL a) key)) (TOK_SELEXPR (. (TOK_TABLE_OR_COL a) value)) (TOK_SELEXPR (. (TOK_TABLE_OR_COL b) value))))) STAGE DEPENDENCIES: Stage-3 is a root stage Stage-1 depends on stages: Stage-3 Stage-0 is a root stage STAGE PLANS: Stage: Stage-3 Map Reduce Local Work Alias -> Map Local Tables: b Fetch Operator limit: -1 Alias -> Map Local Operator Tree: b TableScan alias: b HashTable Sink Operator condition expressions: 0 {key} {value} 1 {value} handleSkewJoin: false keys: 0 [Column[key]] 1 [Column[key]] Position of Big Table: 0 Stage: Stage-1 Map Reduce Alias -> Map Operator Tree: a TableScan alias: a Map Join Operator condition map: Inner Join 0 to 1 condition expressions: 0 {key} {value} 1 {value} handleSkewJoin: false keys: 0 [Column[key]] 1 [Column[key]] outputColumnNames: _col0, _col1, _col6 Position of Big Table: 0 Select Operator expressions: expr: _col0 type: int expr: _col1 type: string expr: _col6 type: string outputColumnNames: _col0, _col1, _col6 Select Operator expressions: expr: _col0 type: int expr: _col1 type: string expr: _col6 type: string outputColumnNames: _col0, _col1, _col2 File Output Operator compressed: false GlobalTableId: 0 table: input format: org.apache.hadoop.mapred.TextInputFormat output format: org.apache.hadoop.hive.ql.io.HiveIgnoreKeyTextOutputFormat Local Work: Map Reduce Local Work Stage: Stage-0 Fetch Operator limit: -1 FAILED: SemanticException [Error 10136]: Bucketed mapjoin cannot be performed. This can be due to multiple reasons: . Join columns dont match bucketed columns. . Number of buckets are not a multiple of each other. If you really want to perform the operation, either remove the mapjoin hint from your query or set hive.enforce.bucketmapjoin to false.