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Posted to commits@hive.apache.org by ke...@apache.org on 2012/12/19 02:20:59 UTC

svn commit: r1423731 [2/2] - in /hive/trunk/ql/src: java/org/apache/hadoop/hive/ql/exec/ java/org/apache/hadoop/hive/ql/optimizer/ java/org/apache/hadoop/hive/ql/parse/ java/org/apache/hadoop/hive/ql/plan/ test/queries/clientpositive/ test/results/clie...

Added: hive/trunk/ql/src/test/results/clientpositive/smb_mapjoin_14.q.out
URL: http://svn.apache.org/viewvc/hive/trunk/ql/src/test/results/clientpositive/smb_mapjoin_14.q.out?rev=1423731&view=auto
==============================================================================
--- hive/trunk/ql/src/test/results/clientpositive/smb_mapjoin_14.q.out (added)
+++ hive/trunk/ql/src/test/results/clientpositive/smb_mapjoin_14.q.out Wed Dec 19 01:20:56 2012
@@ -0,0 +1,2149 @@
+PREHOOK: query: CREATE TABLE tbl1(key int, value string) CLUSTERED BY (key) SORTED BY (key) INTO 2 BUCKETS
+PREHOOK: type: CREATETABLE
+POSTHOOK: query: CREATE TABLE tbl1(key int, value string) CLUSTERED BY (key) SORTED BY (key) INTO 2 BUCKETS
+POSTHOOK: type: CREATETABLE
+POSTHOOK: Output: default@tbl1
+PREHOOK: query: CREATE TABLE tbl2(key int, value string) CLUSTERED BY (key) SORTED BY (key) INTO 2 BUCKETS
+PREHOOK: type: CREATETABLE
+POSTHOOK: query: CREATE TABLE tbl2(key int, value string) CLUSTERED BY (key) SORTED BY (key) INTO 2 BUCKETS
+POSTHOOK: type: CREATETABLE
+POSTHOOK: Output: default@tbl2
+PREHOOK: query: insert overwrite table tbl1
+select * from src where key < 10
+PREHOOK: type: QUERY
+PREHOOK: Input: default@src
+PREHOOK: Output: default@tbl1
+POSTHOOK: query: insert overwrite table tbl1
+select * from src where key < 10
+POSTHOOK: type: QUERY
+POSTHOOK: Input: default@src
+POSTHOOK: Output: default@tbl1
+POSTHOOK: Lineage: tbl1.key EXPRESSION [(src)src.FieldSchema(name:key, type:string, comment:default), ]
+POSTHOOK: Lineage: tbl1.value SIMPLE [(src)src.FieldSchema(name:value, type:string, comment:default), ]
+PREHOOK: query: insert overwrite table tbl2
+select * from src where key < 10
+PREHOOK: type: QUERY
+PREHOOK: Input: default@src
+PREHOOK: Output: default@tbl2
+POSTHOOK: query: insert overwrite table tbl2
+select * from src where key < 10
+POSTHOOK: type: QUERY
+POSTHOOK: Input: default@src
+POSTHOOK: Output: default@tbl2
+POSTHOOK: Lineage: tbl1.key EXPRESSION [(src)src.FieldSchema(name:key, type:string, comment:default), ]
+POSTHOOK: Lineage: tbl1.value SIMPLE [(src)src.FieldSchema(name:value, type:string, comment:default), ]
+POSTHOOK: Lineage: tbl2.key EXPRESSION [(src)src.FieldSchema(name:key, type:string, comment:default), ]
+POSTHOOK: Lineage: tbl2.value SIMPLE [(src)src.FieldSchema(name:value, type:string, comment:default), ]
+PREHOOK: query: -- The mapjoin is being performed as part of sub-query. It should be converted to a sort-merge join
+explain
+select count(*) from (
+  select /*+mapjoin(a)*/ a.key as key, a.value as val1, b.value as val2 from tbl1 a join tbl2 b on a.key = b.key
+) subq1
+PREHOOK: type: QUERY
+POSTHOOK: query: -- The mapjoin is being performed as part of sub-query. It should be converted to a sort-merge join
+explain
+select count(*) from (
+  select /*+mapjoin(a)*/ a.key as key, a.value as val1, b.value as val2 from tbl1 a join tbl2 b on a.key = b.key
+) subq1
+POSTHOOK: type: QUERY
+POSTHOOK: Lineage: tbl1.key EXPRESSION [(src)src.FieldSchema(name:key, type:string, comment:default), ]
+POSTHOOK: Lineage: tbl1.value SIMPLE [(src)src.FieldSchema(name:value, type:string, comment:default), ]
+POSTHOOK: Lineage: tbl2.key EXPRESSION [(src)src.FieldSchema(name:key, type:string, comment:default), ]
+POSTHOOK: Lineage: tbl2.value SIMPLE [(src)src.FieldSchema(name:value, type:string, comment:default), ]
+ABSTRACT SYNTAX TREE:
+  (TOK_QUERY (TOK_FROM (TOK_SUBQUERY (TOK_QUERY (TOK_FROM (TOK_JOIN (TOK_TABREF (TOK_TABNAME tbl1) a) (TOK_TABREF (TOK_TABNAME tbl2) b) (= (. (TOK_TABLE_OR_COL a) key) (. (TOK_TABLE_OR_COL b) key)))) (TOK_INSERT (TOK_DESTINATION (TOK_DIR TOK_TMP_FILE)) (TOK_SELECT (TOK_HINTLIST (TOK_HINT TOK_MAPJOIN (TOK_HINTARGLIST a))) (TOK_SELEXPR (. (TOK_TABLE_OR_COL a) key) key) (TOK_SELEXPR (. (TOK_TABLE_OR_COL a) value) val1) (TOK_SELEXPR (. (TOK_TABLE_OR_COL b) value) val2)))) subq1)) (TOK_INSERT (TOK_DESTINATION (TOK_DIR TOK_TMP_FILE)) (TOK_SELECT (TOK_SELEXPR (TOK_FUNCTIONSTAR count)))))
+
+STAGE DEPENDENCIES:
+  Stage-1 is a root stage
+  Stage-2 depends on stages: Stage-1
+  Stage-0 is a root stage
+
+STAGE PLANS:
+  Stage: Stage-1
+    Map Reduce
+      Alias -> Map Operator Tree:
+        subq1:b 
+          TableScan
+            alias: b
+            Sorted Merge Bucket Map Join Operator
+              condition map:
+                   Inner Join 0 to 1
+              condition expressions:
+                0 
+                1 
+              handleSkewJoin: false
+              keys:
+                0 [Column[key]]
+                1 [Column[key]]
+              Position of Big Table: 1
+              File Output Operator
+                compressed: false
+                GlobalTableId: 0
+                table:
+                    input format: org.apache.hadoop.mapred.SequenceFileInputFormat
+                    output format: org.apache.hadoop.hive.ql.io.HiveSequenceFileOutputFormat
+
+  Stage: Stage-2
+    Map Reduce
+      Alias -> Map Operator Tree:
+#### A masked pattern was here ####
+          Select Operator
+            Select Operator
+              Select Operator
+                Group By Operator
+                  aggregations:
+                        expr: count()
+                  bucketGroup: false
+                  mode: hash
+                  outputColumnNames: _col0
+                  Reduce Output Operator
+                    sort order: 
+                    tag: -1
+                    value expressions:
+                          expr: _col0
+                          type: bigint
+      Reduce Operator Tree:
+        Group By Operator
+          aggregations:
+                expr: count(VALUE._col0)
+          bucketGroup: false
+          mode: mergepartial
+          outputColumnNames: _col0
+          Select Operator
+            expressions:
+                  expr: _col0
+                  type: bigint
+            outputColumnNames: _col0
+            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: select count(*) from (
+  select /*+mapjoin(a)*/ a.key as key, a.value as val1, b.value as val2 from tbl1 a join tbl2 b on a.key = b.key
+) subq1
+PREHOOK: type: QUERY
+PREHOOK: Input: default@tbl1
+PREHOOK: Input: default@tbl2
+#### A masked pattern was here ####
+POSTHOOK: query: select count(*) from (
+  select /*+mapjoin(a)*/ a.key as key, a.value as val1, b.value as val2 from tbl1 a join tbl2 b on a.key = b.key
+) subq1
+POSTHOOK: type: QUERY
+POSTHOOK: Input: default@tbl1
+POSTHOOK: Input: default@tbl2
+#### A masked pattern was here ####
+POSTHOOK: Lineage: tbl1.key EXPRESSION [(src)src.FieldSchema(name:key, type:string, comment:default), ]
+POSTHOOK: Lineage: tbl1.value SIMPLE [(src)src.FieldSchema(name:value, type:string, comment:default), ]
+POSTHOOK: Lineage: tbl2.key EXPRESSION [(src)src.FieldSchema(name:key, type:string, comment:default), ]
+POSTHOOK: Lineage: tbl2.value SIMPLE [(src)src.FieldSchema(name:value, type:string, comment:default), ]
+22
+PREHOOK: query: -- The mapjoin is being performed as part of sub-query. It should be converted to a sort-merge join
+-- Add a order by at the end to make the results deterministic.
+explain
+select key, count(*) from 
+(
+  select /*+mapjoin(a)*/ a.key as key, a.value as val1, b.value as val2 from tbl1 a join tbl2 b on a.key = b.key
+) subq1
+group by key
+order by key
+PREHOOK: type: QUERY
+POSTHOOK: query: -- The mapjoin is being performed as part of sub-query. It should be converted to a sort-merge join
+-- Add a order by at the end to make the results deterministic.
+explain
+select key, count(*) from 
+(
+  select /*+mapjoin(a)*/ a.key as key, a.value as val1, b.value as val2 from tbl1 a join tbl2 b on a.key = b.key
+) subq1
+group by key
+order by key
+POSTHOOK: type: QUERY
+POSTHOOK: Lineage: tbl1.key EXPRESSION [(src)src.FieldSchema(name:key, type:string, comment:default), ]
+POSTHOOK: Lineage: tbl1.value SIMPLE [(src)src.FieldSchema(name:value, type:string, comment:default), ]
+POSTHOOK: Lineage: tbl2.key EXPRESSION [(src)src.FieldSchema(name:key, type:string, comment:default), ]
+POSTHOOK: Lineage: tbl2.value SIMPLE [(src)src.FieldSchema(name:value, type:string, comment:default), ]
+ABSTRACT SYNTAX TREE:
+  (TOK_QUERY (TOK_FROM (TOK_SUBQUERY (TOK_QUERY (TOK_FROM (TOK_JOIN (TOK_TABREF (TOK_TABNAME tbl1) a) (TOK_TABREF (TOK_TABNAME tbl2) b) (= (. (TOK_TABLE_OR_COL a) key) (. (TOK_TABLE_OR_COL b) key)))) (TOK_INSERT (TOK_DESTINATION (TOK_DIR TOK_TMP_FILE)) (TOK_SELECT (TOK_HINTLIST (TOK_HINT TOK_MAPJOIN (TOK_HINTARGLIST a))) (TOK_SELEXPR (. (TOK_TABLE_OR_COL a) key) key) (TOK_SELEXPR (. (TOK_TABLE_OR_COL a) value) val1) (TOK_SELEXPR (. (TOK_TABLE_OR_COL b) value) val2)))) subq1)) (TOK_INSERT (TOK_DESTINATION (TOK_DIR TOK_TMP_FILE)) (TOK_SELECT (TOK_SELEXPR (TOK_TABLE_OR_COL key)) (TOK_SELEXPR (TOK_FUNCTIONSTAR count))) (TOK_GROUPBY (TOK_TABLE_OR_COL key)) (TOK_ORDERBY (TOK_TABSORTCOLNAMEASC (TOK_TABLE_OR_COL key)))))
+
+STAGE DEPENDENCIES:
+  Stage-1 is a root stage
+  Stage-2 depends on stages: Stage-1
+  Stage-3 depends on stages: Stage-2
+  Stage-0 is a root stage
+
+STAGE PLANS:
+  Stage: Stage-1
+    Map Reduce
+      Alias -> Map Operator Tree:
+        subq1:b 
+          TableScan
+            alias: b
+            Sorted Merge Bucket Map Join Operator
+              condition map:
+                   Inner Join 0 to 1
+              condition expressions:
+                0 {key}
+                1 
+              handleSkewJoin: false
+              keys:
+                0 [Column[key]]
+                1 [Column[key]]
+              outputColumnNames: _col0
+              Position of Big Table: 1
+              File Output Operator
+                compressed: false
+                GlobalTableId: 0
+                table:
+                    input format: org.apache.hadoop.mapred.SequenceFileInputFormat
+                    output format: org.apache.hadoop.hive.ql.io.HiveSequenceFileOutputFormat
+
+  Stage: Stage-2
+    Map Reduce
+      Alias -> Map Operator Tree:
+#### A masked pattern was here ####
+          Select Operator
+            expressions:
+                  expr: _col0
+                  type: int
+            outputColumnNames: _col0
+            Select Operator
+              expressions:
+                    expr: _col0
+                    type: int
+              outputColumnNames: _col0
+              Select Operator
+                expressions:
+                      expr: _col0
+                      type: int
+                outputColumnNames: _col0
+                Group By Operator
+                  aggregations:
+                        expr: count()
+                  bucketGroup: false
+                  keys:
+                        expr: _col0
+                        type: int
+                  mode: hash
+                  outputColumnNames: _col0, _col1
+                  Reduce Output Operator
+                    key expressions:
+                          expr: _col0
+                          type: int
+                    sort order: +
+                    Map-reduce partition columns:
+                          expr: _col0
+                          type: int
+                    tag: -1
+                    value expressions:
+                          expr: _col1
+                          type: bigint
+      Reduce Operator Tree:
+        Group By Operator
+          aggregations:
+                expr: count(VALUE._col0)
+          bucketGroup: false
+          keys:
+                expr: KEY._col0
+                type: int
+          mode: mergepartial
+          outputColumnNames: _col0, _col1
+          Select Operator
+            expressions:
+                  expr: _col0
+                  type: int
+                  expr: _col1
+                  type: bigint
+            outputColumnNames: _col0, _col1
+            File Output Operator
+              compressed: false
+              GlobalTableId: 0
+              table:
+                  input format: org.apache.hadoop.mapred.SequenceFileInputFormat
+                  output format: org.apache.hadoop.hive.ql.io.HiveSequenceFileOutputFormat
+
+  Stage: Stage-3
+    Map Reduce
+      Alias -> Map Operator Tree:
+#### A masked pattern was here ####
+            Reduce Output Operator
+              key expressions:
+                    expr: _col0
+                    type: int
+              sort order: +
+              tag: -1
+              value expressions:
+                    expr: _col0
+                    type: int
+                    expr: _col1
+                    type: bigint
+      Reduce Operator Tree:
+        Extract
+          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: select key, count(*) from 
+(
+  select /*+mapjoin(a)*/ a.key as key, a.value as val1, b.value as val2 from tbl1 a join tbl2 b on a.key = b.key
+) subq1
+group by key
+order by key
+PREHOOK: type: QUERY
+PREHOOK: Input: default@tbl1
+PREHOOK: Input: default@tbl2
+#### A masked pattern was here ####
+POSTHOOK: query: select key, count(*) from 
+(
+  select /*+mapjoin(a)*/ a.key as key, a.value as val1, b.value as val2 from tbl1 a join tbl2 b on a.key = b.key
+) subq1
+group by key
+order by key
+POSTHOOK: type: QUERY
+POSTHOOK: Input: default@tbl1
+POSTHOOK: Input: default@tbl2
+#### A masked pattern was here ####
+POSTHOOK: Lineage: tbl1.key EXPRESSION [(src)src.FieldSchema(name:key, type:string, comment:default), ]
+POSTHOOK: Lineage: tbl1.value SIMPLE [(src)src.FieldSchema(name:value, type:string, comment:default), ]
+POSTHOOK: Lineage: tbl2.key EXPRESSION [(src)src.FieldSchema(name:key, type:string, comment:default), ]
+POSTHOOK: Lineage: tbl2.value SIMPLE [(src)src.FieldSchema(name:value, type:string, comment:default), ]
+0	9
+2	1
+4	1
+5	9
+8	1
+9	1
+PREHOOK: query: -- The mapjoin is being performed as part of more than one sub-query. It should be converted to a sort-merge join
+explain
+select count(*) from
+(
+  select key, count(*) from 
+  (
+    select /*+mapjoin(a)*/ a.key as key, a.value as val1, b.value as val2 from tbl1 a join tbl2 b on a.key = b.key
+  ) subq1
+  group by key
+) subq2
+PREHOOK: type: QUERY
+POSTHOOK: query: -- The mapjoin is being performed as part of more than one sub-query. It should be converted to a sort-merge join
+explain
+select count(*) from
+(
+  select key, count(*) from 
+  (
+    select /*+mapjoin(a)*/ a.key as key, a.value as val1, b.value as val2 from tbl1 a join tbl2 b on a.key = b.key
+  ) subq1
+  group by key
+) subq2
+POSTHOOK: type: QUERY
+POSTHOOK: Lineage: tbl1.key EXPRESSION [(src)src.FieldSchema(name:key, type:string, comment:default), ]
+POSTHOOK: Lineage: tbl1.value SIMPLE [(src)src.FieldSchema(name:value, type:string, comment:default), ]
+POSTHOOK: Lineage: tbl2.key EXPRESSION [(src)src.FieldSchema(name:key, type:string, comment:default), ]
+POSTHOOK: Lineage: tbl2.value SIMPLE [(src)src.FieldSchema(name:value, type:string, comment:default), ]
+ABSTRACT SYNTAX TREE:
+  (TOK_QUERY (TOK_FROM (TOK_SUBQUERY (TOK_QUERY (TOK_FROM (TOK_SUBQUERY (TOK_QUERY (TOK_FROM (TOK_JOIN (TOK_TABREF (TOK_TABNAME tbl1) a) (TOK_TABREF (TOK_TABNAME tbl2) b) (= (. (TOK_TABLE_OR_COL a) key) (. (TOK_TABLE_OR_COL b) key)))) (TOK_INSERT (TOK_DESTINATION (TOK_DIR TOK_TMP_FILE)) (TOK_SELECT (TOK_HINTLIST (TOK_HINT TOK_MAPJOIN (TOK_HINTARGLIST a))) (TOK_SELEXPR (. (TOK_TABLE_OR_COL a) key) key) (TOK_SELEXPR (. (TOK_TABLE_OR_COL a) value) val1) (TOK_SELEXPR (. (TOK_TABLE_OR_COL b) value) val2)))) subq1)) (TOK_INSERT (TOK_DESTINATION (TOK_DIR TOK_TMP_FILE)) (TOK_SELECT (TOK_SELEXPR (TOK_TABLE_OR_COL key)) (TOK_SELEXPR (TOK_FUNCTIONSTAR count))) (TOK_GROUPBY (TOK_TABLE_OR_COL key)))) subq2)) (TOK_INSERT (TOK_DESTINATION (TOK_DIR TOK_TMP_FILE)) (TOK_SELECT (TOK_SELEXPR (TOK_FUNCTIONSTAR count)))))
+
+STAGE DEPENDENCIES:
+  Stage-1 is a root stage
+  Stage-2 depends on stages: Stage-1
+  Stage-3 depends on stages: Stage-2
+  Stage-0 is a root stage
+
+STAGE PLANS:
+  Stage: Stage-1
+    Map Reduce
+      Alias -> Map Operator Tree:
+        subq2:subq1:b 
+          TableScan
+            alias: b
+            Sorted Merge Bucket Map Join Operator
+              condition map:
+                   Inner Join 0 to 1
+              condition expressions:
+                0 {key}
+                1 
+              handleSkewJoin: false
+              keys:
+                0 [Column[key]]
+                1 [Column[key]]
+              outputColumnNames: _col0
+              Position of Big Table: 1
+              File Output Operator
+                compressed: false
+                GlobalTableId: 0
+                table:
+                    input format: org.apache.hadoop.mapred.SequenceFileInputFormat
+                    output format: org.apache.hadoop.hive.ql.io.HiveSequenceFileOutputFormat
+
+  Stage: Stage-2
+    Map Reduce
+      Alias -> Map Operator Tree:
+#### A masked pattern was here ####
+          Select Operator
+            expressions:
+                  expr: _col0
+                  type: int
+            outputColumnNames: _col0
+            Select Operator
+              expressions:
+                    expr: _col0
+                    type: int
+              outputColumnNames: _col0
+              Select Operator
+                expressions:
+                      expr: _col0
+                      type: int
+                outputColumnNames: _col0
+                Group By Operator
+                  aggregations:
+                        expr: count()
+                  bucketGroup: false
+                  keys:
+                        expr: _col0
+                        type: int
+                  mode: hash
+                  outputColumnNames: _col0, _col1
+                  Reduce Output Operator
+                    key expressions:
+                          expr: _col0
+                          type: int
+                    sort order: +
+                    Map-reduce partition columns:
+                          expr: _col0
+                          type: int
+                    tag: -1
+                    value expressions:
+                          expr: _col1
+                          type: bigint
+      Reduce Operator Tree:
+        Group By Operator
+          aggregations:
+                expr: count(VALUE._col0)
+          bucketGroup: false
+          keys:
+                expr: KEY._col0
+                type: int
+          mode: mergepartial
+          outputColumnNames: _col0, _col1
+          Select Operator
+            Select Operator
+              Group By Operator
+                aggregations:
+                      expr: count()
+                bucketGroup: false
+                mode: hash
+                outputColumnNames: _col0
+                File Output Operator
+                  compressed: false
+                  GlobalTableId: 0
+                  table:
+                      input format: org.apache.hadoop.mapred.SequenceFileInputFormat
+                      output format: org.apache.hadoop.hive.ql.io.HiveSequenceFileOutputFormat
+
+  Stage: Stage-3
+    Map Reduce
+      Alias -> Map Operator Tree:
+#### A masked pattern was here ####
+            Reduce Output Operator
+              sort order: 
+              tag: -1
+              value expressions:
+                    expr: _col0
+                    type: bigint
+      Reduce Operator Tree:
+        Group By Operator
+          aggregations:
+                expr: count(VALUE._col0)
+          bucketGroup: false
+          mode: mergepartial
+          outputColumnNames: _col0
+          Select Operator
+            expressions:
+                  expr: _col0
+                  type: bigint
+            outputColumnNames: _col0
+            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: select count(*) from
+(
+  select key, count(*) from 
+  (
+    select /*+mapjoin(a)*/ a.key as key, a.value as val1, b.value as val2 from tbl1 a join tbl2 b on a.key = b.key
+  ) subq1
+  group by key
+) subq2
+PREHOOK: type: QUERY
+PREHOOK: Input: default@tbl1
+PREHOOK: Input: default@tbl2
+#### A masked pattern was here ####
+POSTHOOK: query: select count(*) from
+(
+  select key, count(*) from 
+  (
+    select /*+mapjoin(a)*/ a.key as key, a.value as val1, b.value as val2 from tbl1 a join tbl2 b on a.key = b.key
+  ) subq1
+  group by key
+) subq2
+POSTHOOK: type: QUERY
+POSTHOOK: Input: default@tbl1
+POSTHOOK: Input: default@tbl2
+#### A masked pattern was here ####
+POSTHOOK: Lineage: tbl1.key EXPRESSION [(src)src.FieldSchema(name:key, type:string, comment:default), ]
+POSTHOOK: Lineage: tbl1.value SIMPLE [(src)src.FieldSchema(name:value, type:string, comment:default), ]
+POSTHOOK: Lineage: tbl2.key EXPRESSION [(src)src.FieldSchema(name:key, type:string, comment:default), ]
+POSTHOOK: Lineage: tbl2.value SIMPLE [(src)src.FieldSchema(name:value, type:string, comment:default), ]
+6
+PREHOOK: query: -- A join is being performed across different sub-queries, where a mapjoin is being performed in each of them.
+-- Each sub-query should be converted to a sort-merge join.
+explain
+select src1.key, src1.cnt1, src2.cnt1 from
+(
+  select key, count(*) as cnt1 from 
+  (
+    select /*+mapjoin(a)*/ a.key as key, a.value as val1, b.value as val2 from tbl1 a join tbl2 b on a.key = b.key
+  ) subq1 group by key
+) src1
+join
+(
+  select key, count(*) as cnt1 from 
+  (
+    select /*+mapjoin(a)*/ a.key as key, a.value as val1, b.value as val2 from tbl1 a join tbl2 b on a.key = b.key
+  ) subq2 group by key
+) src2
+on src1.key = src2.key
+order by src1.key, src1.cnt1, src2.cnt1
+PREHOOK: type: QUERY
+POSTHOOK: query: -- A join is being performed across different sub-queries, where a mapjoin is being performed in each of them.
+-- Each sub-query should be converted to a sort-merge join.
+explain
+select src1.key, src1.cnt1, src2.cnt1 from
+(
+  select key, count(*) as cnt1 from 
+  (
+    select /*+mapjoin(a)*/ a.key as key, a.value as val1, b.value as val2 from tbl1 a join tbl2 b on a.key = b.key
+  ) subq1 group by key
+) src1
+join
+(
+  select key, count(*) as cnt1 from 
+  (
+    select /*+mapjoin(a)*/ a.key as key, a.value as val1, b.value as val2 from tbl1 a join tbl2 b on a.key = b.key
+  ) subq2 group by key
+) src2
+on src1.key = src2.key
+order by src1.key, src1.cnt1, src2.cnt1
+POSTHOOK: type: QUERY
+POSTHOOK: Lineage: tbl1.key EXPRESSION [(src)src.FieldSchema(name:key, type:string, comment:default), ]
+POSTHOOK: Lineage: tbl1.value SIMPLE [(src)src.FieldSchema(name:value, type:string, comment:default), ]
+POSTHOOK: Lineage: tbl2.key EXPRESSION [(src)src.FieldSchema(name:key, type:string, comment:default), ]
+POSTHOOK: Lineage: tbl2.value SIMPLE [(src)src.FieldSchema(name:value, type:string, comment:default), ]
+ABSTRACT SYNTAX TREE:
+  (TOK_QUERY (TOK_FROM (TOK_JOIN (TOK_SUBQUERY (TOK_QUERY (TOK_FROM (TOK_SUBQUERY (TOK_QUERY (TOK_FROM (TOK_JOIN (TOK_TABREF (TOK_TABNAME tbl1) a) (TOK_TABREF (TOK_TABNAME tbl2) b) (= (. (TOK_TABLE_OR_COL a) key) (. (TOK_TABLE_OR_COL b) key)))) (TOK_INSERT (TOK_DESTINATION (TOK_DIR TOK_TMP_FILE)) (TOK_SELECT (TOK_HINTLIST (TOK_HINT TOK_MAPJOIN (TOK_HINTARGLIST a))) (TOK_SELEXPR (. (TOK_TABLE_OR_COL a) key) key) (TOK_SELEXPR (. (TOK_TABLE_OR_COL a) value) val1) (TOK_SELEXPR (. (TOK_TABLE_OR_COL b) value) val2)))) subq1)) (TOK_INSERT (TOK_DESTINATION (TOK_DIR TOK_TMP_FILE)) (TOK_SELECT (TOK_SELEXPR (TOK_TABLE_OR_COL key)) (TOK_SELEXPR (TOK_FUNCTIONSTAR count) cnt1)) (TOK_GROUPBY (TOK_TABLE_OR_COL key)))) src1) (TOK_SUBQUERY (TOK_QUERY (TOK_FROM (TOK_SUBQUERY (TOK_QUERY (TOK_FROM (TOK_JOIN (TOK_TABREF (TOK_TABNAME tbl1) a) (TOK_TABREF (TOK_TABNAME tbl2) b) (= (. (TOK_TABLE_OR_COL a) key) (. (TOK_TABLE_OR_COL b) key)))) (TOK_INSERT (TOK_DESTINATION (TOK_DIR TOK_TMP_FILE)) (TOK_S
 ELECT (TOK_HINTLIST (TOK_HINT TOK_MAPJOIN (TOK_HINTARGLIST a))) (TOK_SELEXPR (. (TOK_TABLE_OR_COL a) key) key) (TOK_SELEXPR (. (TOK_TABLE_OR_COL a) value) val1) (TOK_SELEXPR (. (TOK_TABLE_OR_COL b) value) val2)))) subq2)) (TOK_INSERT (TOK_DESTINATION (TOK_DIR TOK_TMP_FILE)) (TOK_SELECT (TOK_SELEXPR (TOK_TABLE_OR_COL key)) (TOK_SELEXPR (TOK_FUNCTIONSTAR count) cnt1)) (TOK_GROUPBY (TOK_TABLE_OR_COL key)))) src2) (= (. (TOK_TABLE_OR_COL src1) key) (. (TOK_TABLE_OR_COL src2) key)))) (TOK_INSERT (TOK_DESTINATION (TOK_DIR TOK_TMP_FILE)) (TOK_SELECT (TOK_SELEXPR (. (TOK_TABLE_OR_COL src1) key)) (TOK_SELEXPR (. (TOK_TABLE_OR_COL src1) cnt1)) (TOK_SELEXPR (. (TOK_TABLE_OR_COL src2) cnt1))) (TOK_ORDERBY (TOK_TABSORTCOLNAMEASC (. (TOK_TABLE_OR_COL src1) key)) (TOK_TABSORTCOLNAMEASC (. (TOK_TABLE_OR_COL src1) cnt1)) (TOK_TABSORTCOLNAMEASC (. (TOK_TABLE_OR_COL src2) cnt1)))))
+
+STAGE DEPENDENCIES:
+  Stage-1 is a root stage
+  Stage-2 depends on stages: Stage-1
+  Stage-3 depends on stages: Stage-2, Stage-7
+  Stage-4 depends on stages: Stage-3
+  Stage-6 is a root stage
+  Stage-7 depends on stages: Stage-6
+  Stage-0 is a root stage
+
+STAGE PLANS:
+  Stage: Stage-1
+    Map Reduce
+      Alias -> Map Operator Tree:
+        src1:subq1:b 
+          TableScan
+            alias: b
+            Sorted Merge Bucket Map Join Operator
+              condition map:
+                   Inner Join 0 to 1
+              condition expressions:
+                0 {key}
+                1 
+              handleSkewJoin: false
+              keys:
+                0 [Column[key]]
+                1 [Column[key]]
+              outputColumnNames: _col0
+              Position of Big Table: 1
+              File Output Operator
+                compressed: false
+                GlobalTableId: 0
+                table:
+                    input format: org.apache.hadoop.mapred.SequenceFileInputFormat
+                    output format: org.apache.hadoop.hive.ql.io.HiveSequenceFileOutputFormat
+
+  Stage: Stage-2
+    Map Reduce
+      Alias -> Map Operator Tree:
+#### A masked pattern was here ####
+          Select Operator
+            expressions:
+                  expr: _col0
+                  type: int
+            outputColumnNames: _col0
+            Select Operator
+              expressions:
+                    expr: _col0
+                    type: int
+              outputColumnNames: _col0
+              Select Operator
+                expressions:
+                      expr: _col0
+                      type: int
+                outputColumnNames: _col0
+                Group By Operator
+                  aggregations:
+                        expr: count()
+                  bucketGroup: false
+                  keys:
+                        expr: _col0
+                        type: int
+                  mode: hash
+                  outputColumnNames: _col0, _col1
+                  Reduce Output Operator
+                    key expressions:
+                          expr: _col0
+                          type: int
+                    sort order: +
+                    Map-reduce partition columns:
+                          expr: _col0
+                          type: int
+                    tag: -1
+                    value expressions:
+                          expr: _col1
+                          type: bigint
+      Reduce Operator Tree:
+        Group By Operator
+          aggregations:
+                expr: count(VALUE._col0)
+          bucketGroup: false
+          keys:
+                expr: KEY._col0
+                type: int
+          mode: mergepartial
+          outputColumnNames: _col0, _col1
+          Select Operator
+            expressions:
+                  expr: _col0
+                  type: int
+                  expr: _col1
+                  type: bigint
+            outputColumnNames: _col0, _col1
+            File Output Operator
+              compressed: false
+              GlobalTableId: 0
+              table:
+                  input format: org.apache.hadoop.mapred.SequenceFileInputFormat
+                  output format: org.apache.hadoop.hive.ql.io.HiveSequenceFileOutputFormat
+
+  Stage: Stage-3
+    Map Reduce
+      Alias -> Map Operator Tree:
+        $INTNAME 
+            Reduce Output Operator
+              key expressions:
+                    expr: _col0
+                    type: int
+              sort order: +
+              Map-reduce partition columns:
+                    expr: _col0
+                    type: int
+              tag: 0
+              value expressions:
+                    expr: _col0
+                    type: int
+                    expr: _col1
+                    type: bigint
+        $INTNAME1 
+            Reduce Output Operator
+              key expressions:
+                    expr: _col0
+                    type: int
+              sort order: +
+              Map-reduce partition columns:
+                    expr: _col0
+                    type: int
+              tag: 1
+              value expressions:
+                    expr: _col1
+                    type: bigint
+      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, _col3
+          Select Operator
+            expressions:
+                  expr: _col0
+                  type: int
+                  expr: _col1
+                  type: bigint
+                  expr: _col3
+                  type: bigint
+            outputColumnNames: _col0, _col1, _col2
+            File Output Operator
+              compressed: false
+              GlobalTableId: 0
+              table:
+                  input format: org.apache.hadoop.mapred.SequenceFileInputFormat
+                  output format: org.apache.hadoop.hive.ql.io.HiveSequenceFileOutputFormat
+
+  Stage: Stage-4
+    Map Reduce
+      Alias -> Map Operator Tree:
+#### A masked pattern was here ####
+            Reduce Output Operator
+              key expressions:
+                    expr: _col0
+                    type: int
+                    expr: _col1
+                    type: bigint
+                    expr: _col2
+                    type: bigint
+              sort order: +++
+              tag: -1
+              value expressions:
+                    expr: _col0
+                    type: int
+                    expr: _col1
+                    type: bigint
+                    expr: _col2
+                    type: bigint
+      Reduce Operator Tree:
+        Extract
+          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-6
+    Map Reduce
+      Alias -> Map Operator Tree:
+        src2:subq2:b 
+          TableScan
+            alias: b
+            Sorted Merge Bucket Map Join Operator
+              condition map:
+                   Inner Join 0 to 1
+              condition expressions:
+                0 {key}
+                1 
+              handleSkewJoin: false
+              keys:
+                0 [Column[key]]
+                1 [Column[key]]
+              outputColumnNames: _col0
+              Position of Big Table: 1
+              File Output Operator
+                compressed: false
+                GlobalTableId: 0
+                table:
+                    input format: org.apache.hadoop.mapred.SequenceFileInputFormat
+                    output format: org.apache.hadoop.hive.ql.io.HiveSequenceFileOutputFormat
+
+  Stage: Stage-7
+    Map Reduce
+      Alias -> Map Operator Tree:
+#### A masked pattern was here ####
+          Select Operator
+            expressions:
+                  expr: _col0
+                  type: int
+            outputColumnNames: _col0
+            Select Operator
+              expressions:
+                    expr: _col0
+                    type: int
+              outputColumnNames: _col0
+              Select Operator
+                expressions:
+                      expr: _col0
+                      type: int
+                outputColumnNames: _col0
+                Group By Operator
+                  aggregations:
+                        expr: count()
+                  bucketGroup: false
+                  keys:
+                        expr: _col0
+                        type: int
+                  mode: hash
+                  outputColumnNames: _col0, _col1
+                  Reduce Output Operator
+                    key expressions:
+                          expr: _col0
+                          type: int
+                    sort order: +
+                    Map-reduce partition columns:
+                          expr: _col0
+                          type: int
+                    tag: -1
+                    value expressions:
+                          expr: _col1
+                          type: bigint
+      Reduce Operator Tree:
+        Group By Operator
+          aggregations:
+                expr: count(VALUE._col0)
+          bucketGroup: false
+          keys:
+                expr: KEY._col0
+                type: int
+          mode: mergepartial
+          outputColumnNames: _col0, _col1
+          Select Operator
+            expressions:
+                  expr: _col0
+                  type: int
+                  expr: _col1
+                  type: bigint
+            outputColumnNames: _col0, _col1
+            File Output Operator
+              compressed: false
+              GlobalTableId: 0
+              table:
+                  input format: org.apache.hadoop.mapred.SequenceFileInputFormat
+                  output format: org.apache.hadoop.hive.ql.io.HiveSequenceFileOutputFormat
+
+  Stage: Stage-0
+    Fetch Operator
+      limit: -1
+
+
+PREHOOK: query: select src1.key, src1.cnt1, src2.cnt1 from
+(
+  select key, count(*) as cnt1 from 
+  (
+    select /*+mapjoin(a)*/ a.key as key, a.value as val1, b.value as val2 from tbl1 a join tbl2 b on a.key = b.key
+  ) subq1 group by key
+) src1
+join
+(
+  select key, count(*) as cnt1 from 
+  (
+    select /*+mapjoin(a)*/ a.key as key, a.value as val1, b.value as val2 from tbl1 a join tbl2 b on a.key = b.key
+  ) subq2 group by key
+) src2
+on src1.key = src2.key
+order by src1.key, src1.cnt1, src2.cnt1
+PREHOOK: type: QUERY
+PREHOOK: Input: default@tbl1
+PREHOOK: Input: default@tbl2
+#### A masked pattern was here ####
+POSTHOOK: query: select src1.key, src1.cnt1, src2.cnt1 from
+(
+  select key, count(*) as cnt1 from 
+  (
+    select /*+mapjoin(a)*/ a.key as key, a.value as val1, b.value as val2 from tbl1 a join tbl2 b on a.key = b.key
+  ) subq1 group by key
+) src1
+join
+(
+  select key, count(*) as cnt1 from 
+  (
+    select /*+mapjoin(a)*/ a.key as key, a.value as val1, b.value as val2 from tbl1 a join tbl2 b on a.key = b.key
+  ) subq2 group by key
+) src2
+on src1.key = src2.key
+order by src1.key, src1.cnt1, src2.cnt1
+POSTHOOK: type: QUERY
+POSTHOOK: Input: default@tbl1
+POSTHOOK: Input: default@tbl2
+#### A masked pattern was here ####
+POSTHOOK: Lineage: tbl1.key EXPRESSION [(src)src.FieldSchema(name:key, type:string, comment:default), ]
+POSTHOOK: Lineage: tbl1.value SIMPLE [(src)src.FieldSchema(name:value, type:string, comment:default), ]
+POSTHOOK: Lineage: tbl2.key EXPRESSION [(src)src.FieldSchema(name:key, type:string, comment:default), ]
+POSTHOOK: Lineage: tbl2.value SIMPLE [(src)src.FieldSchema(name:value, type:string, comment:default), ]
+0	9	9
+2	1	1
+4	1	1
+5	9	9
+8	1	1
+9	1	1
+PREHOOK: query: -- The subquery itself is being map-joined. Since the sub-query only contains selects and filters, it should 
+-- be converted to a sort-merge join.
+explain
+select /*+mapjoin(subq1)*/ count(*) from 
+  (select a.key as key, a.value as value from tbl1 a where key < 6) subq1 
+    join
+  (select a.key as key, a.value as value from tbl2 a where key < 6) subq2
+  on subq1.key = subq2.key
+PREHOOK: type: QUERY
+POSTHOOK: query: -- The subquery itself is being map-joined. Since the sub-query only contains selects and filters, it should 
+-- be converted to a sort-merge join.
+explain
+select /*+mapjoin(subq1)*/ count(*) from 
+  (select a.key as key, a.value as value from tbl1 a where key < 6) subq1 
+    join
+  (select a.key as key, a.value as value from tbl2 a where key < 6) subq2
+  on subq1.key = subq2.key
+POSTHOOK: type: QUERY
+POSTHOOK: Lineage: tbl1.key EXPRESSION [(src)src.FieldSchema(name:key, type:string, comment:default), ]
+POSTHOOK: Lineage: tbl1.value SIMPLE [(src)src.FieldSchema(name:value, type:string, comment:default), ]
+POSTHOOK: Lineage: tbl2.key EXPRESSION [(src)src.FieldSchema(name:key, type:string, comment:default), ]
+POSTHOOK: Lineage: tbl2.value SIMPLE [(src)src.FieldSchema(name:value, type:string, comment:default), ]
+ABSTRACT SYNTAX TREE:
+  (TOK_QUERY (TOK_FROM (TOK_JOIN (TOK_SUBQUERY (TOK_QUERY (TOK_FROM (TOK_TABREF (TOK_TABNAME tbl1) a)) (TOK_INSERT (TOK_DESTINATION (TOK_DIR TOK_TMP_FILE)) (TOK_SELECT (TOK_SELEXPR (. (TOK_TABLE_OR_COL a) key) key) (TOK_SELEXPR (. (TOK_TABLE_OR_COL a) value) value)) (TOK_WHERE (< (TOK_TABLE_OR_COL key) 6)))) subq1) (TOK_SUBQUERY (TOK_QUERY (TOK_FROM (TOK_TABREF (TOK_TABNAME tbl2) a)) (TOK_INSERT (TOK_DESTINATION (TOK_DIR TOK_TMP_FILE)) (TOK_SELECT (TOK_SELEXPR (. (TOK_TABLE_OR_COL a) key) key) (TOK_SELEXPR (. (TOK_TABLE_OR_COL a) value) value)) (TOK_WHERE (< (TOK_TABLE_OR_COL key) 6)))) subq2) (= (. (TOK_TABLE_OR_COL subq1) key) (. (TOK_TABLE_OR_COL subq2) key)))) (TOK_INSERT (TOK_DESTINATION (TOK_DIR TOK_TMP_FILE)) (TOK_SELECT (TOK_HINTLIST (TOK_HINT TOK_MAPJOIN (TOK_HINTARGLIST subq1))) (TOK_SELEXPR (TOK_FUNCTIONSTAR count)))))
+
+STAGE DEPENDENCIES:
+  Stage-1 is a root stage
+  Stage-2 depends on stages: Stage-1
+  Stage-0 is a root stage
+
+STAGE PLANS:
+  Stage: Stage-1
+    Map Reduce
+      Alias -> Map Operator Tree:
+        subq2:a 
+          TableScan
+            alias: a
+            Filter Operator
+              predicate:
+                  expr: (key < 6)
+                  type: boolean
+              Select Operator
+                expressions:
+                      expr: key
+                      type: int
+                outputColumnNames: _col0
+                Sorted Merge Bucket Map Join Operator
+                  condition map:
+                       Inner Join 0 to 1
+                  condition expressions:
+                    0 
+                    1 
+                  handleSkewJoin: false
+                  keys:
+                    0 [Column[_col0]]
+                    1 [Column[_col0]]
+                  Position of Big Table: 1
+                  File Output Operator
+                    compressed: false
+                    GlobalTableId: 0
+                    table:
+                        input format: org.apache.hadoop.mapred.SequenceFileInputFormat
+                        output format: org.apache.hadoop.hive.ql.io.HiveSequenceFileOutputFormat
+
+  Stage: Stage-2
+    Map Reduce
+      Alias -> Map Operator Tree:
+#### A masked pattern was here ####
+          Select Operator
+            Select Operator
+              Group By Operator
+                aggregations:
+                      expr: count()
+                bucketGroup: false
+                mode: hash
+                outputColumnNames: _col0
+                Reduce Output Operator
+                  sort order: 
+                  tag: -1
+                  value expressions:
+                        expr: _col0
+                        type: bigint
+      Reduce Operator Tree:
+        Group By Operator
+          aggregations:
+                expr: count(VALUE._col0)
+          bucketGroup: false
+          mode: mergepartial
+          outputColumnNames: _col0
+          Select Operator
+            expressions:
+                  expr: _col0
+                  type: bigint
+            outputColumnNames: _col0
+            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: select /*+mapjoin(subq1)*/ count(*) from 
+  (select a.key as key, a.value as value from tbl1 a where key < 6) subq1 
+    join
+  (select a.key as key, a.value as value from tbl2 a where key < 6) subq2
+  on subq1.key = subq2.key
+PREHOOK: type: QUERY
+PREHOOK: Input: default@tbl1
+PREHOOK: Input: default@tbl2
+#### A masked pattern was here ####
+POSTHOOK: query: select /*+mapjoin(subq1)*/ count(*) from 
+  (select a.key as key, a.value as value from tbl1 a where key < 6) subq1 
+    join
+  (select a.key as key, a.value as value from tbl2 a where key < 6) subq2
+  on subq1.key = subq2.key
+POSTHOOK: type: QUERY
+POSTHOOK: Input: default@tbl1
+POSTHOOK: Input: default@tbl2
+#### A masked pattern was here ####
+POSTHOOK: Lineage: tbl1.key EXPRESSION [(src)src.FieldSchema(name:key, type:string, comment:default), ]
+POSTHOOK: Lineage: tbl1.value SIMPLE [(src)src.FieldSchema(name:value, type:string, comment:default), ]
+POSTHOOK: Lineage: tbl2.key EXPRESSION [(src)src.FieldSchema(name:key, type:string, comment:default), ]
+POSTHOOK: Lineage: tbl2.value SIMPLE [(src)src.FieldSchema(name:value, type:string, comment:default), ]
+20
+PREHOOK: query: -- The subquery itself is being map-joined. Since the sub-query only contains selects and filters, it should 
+-- be converted to a sort-merge join, although there is more than one level of sub-query
+explain
+select /*+mapjoin(subq2)*/ count(*) from 
+  (
+  select * from
+    (
+      select a.key as key, a.value as value from tbl1 a where key < 8
+    ) subq1 
+  where key < 6
+  ) subq2
+  join tbl2 b
+  on subq2.key = b.key
+PREHOOK: type: QUERY
+POSTHOOK: query: -- The subquery itself is being map-joined. Since the sub-query only contains selects and filters, it should 
+-- be converted to a sort-merge join, although there is more than one level of sub-query
+explain
+select /*+mapjoin(subq2)*/ count(*) from 
+  (
+  select * from
+    (
+      select a.key as key, a.value as value from tbl1 a where key < 8
+    ) subq1 
+  where key < 6
+  ) subq2
+  join tbl2 b
+  on subq2.key = b.key
+POSTHOOK: type: QUERY
+POSTHOOK: Lineage: tbl1.key EXPRESSION [(src)src.FieldSchema(name:key, type:string, comment:default), ]
+POSTHOOK: Lineage: tbl1.value SIMPLE [(src)src.FieldSchema(name:value, type:string, comment:default), ]
+POSTHOOK: Lineage: tbl2.key EXPRESSION [(src)src.FieldSchema(name:key, type:string, comment:default), ]
+POSTHOOK: Lineage: tbl2.value SIMPLE [(src)src.FieldSchema(name:value, type:string, comment:default), ]
+ABSTRACT SYNTAX TREE:
+  (TOK_QUERY (TOK_FROM (TOK_JOIN (TOK_SUBQUERY (TOK_QUERY (TOK_FROM (TOK_SUBQUERY (TOK_QUERY (TOK_FROM (TOK_TABREF (TOK_TABNAME tbl1) a)) (TOK_INSERT (TOK_DESTINATION (TOK_DIR TOK_TMP_FILE)) (TOK_SELECT (TOK_SELEXPR (. (TOK_TABLE_OR_COL a) key) key) (TOK_SELEXPR (. (TOK_TABLE_OR_COL a) value) value)) (TOK_WHERE (< (TOK_TABLE_OR_COL key) 8)))) subq1)) (TOK_INSERT (TOK_DESTINATION (TOK_DIR TOK_TMP_FILE)) (TOK_SELECT (TOK_SELEXPR TOK_ALLCOLREF)) (TOK_WHERE (< (TOK_TABLE_OR_COL key) 6)))) subq2) (TOK_TABREF (TOK_TABNAME tbl2) b) (= (. (TOK_TABLE_OR_COL subq2) key) (. (TOK_TABLE_OR_COL b) key)))) (TOK_INSERT (TOK_DESTINATION (TOK_DIR TOK_TMP_FILE)) (TOK_SELECT (TOK_HINTLIST (TOK_HINT TOK_MAPJOIN (TOK_HINTARGLIST subq2))) (TOK_SELEXPR (TOK_FUNCTIONSTAR count)))))
+
+STAGE DEPENDENCIES:
+  Stage-1 is a root stage
+  Stage-2 depends on stages: Stage-1
+  Stage-0 is a root stage
+
+STAGE PLANS:
+  Stage: Stage-1
+    Map Reduce
+      Alias -> Map Operator Tree:
+        b 
+          TableScan
+            alias: b
+            Sorted Merge Bucket Map Join Operator
+              condition map:
+                   Inner Join 0 to 1
+              condition expressions:
+                0 
+                1 
+              handleSkewJoin: false
+              keys:
+                0 [Column[_col0]]
+                1 [Column[key]]
+              Position of Big Table: 1
+              File Output Operator
+                compressed: false
+                GlobalTableId: 0
+                table:
+                    input format: org.apache.hadoop.mapred.SequenceFileInputFormat
+                    output format: org.apache.hadoop.hive.ql.io.HiveSequenceFileOutputFormat
+
+  Stage: Stage-2
+    Map Reduce
+      Alias -> Map Operator Tree:
+#### A masked pattern was here ####
+          Select Operator
+            Select Operator
+              Group By Operator
+                aggregations:
+                      expr: count()
+                bucketGroup: false
+                mode: hash
+                outputColumnNames: _col0
+                Reduce Output Operator
+                  sort order: 
+                  tag: -1
+                  value expressions:
+                        expr: _col0
+                        type: bigint
+      Reduce Operator Tree:
+        Group By Operator
+          aggregations:
+                expr: count(VALUE._col0)
+          bucketGroup: false
+          mode: mergepartial
+          outputColumnNames: _col0
+          Select Operator
+            expressions:
+                  expr: _col0
+                  type: bigint
+            outputColumnNames: _col0
+            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: select /*+mapjoin(subq2)*/ count(*) from 
+  (
+  select * from
+    (
+      select a.key as key, a.value as value from tbl1 a where key < 8
+    ) subq1 
+  where key < 6
+  ) subq2
+  join tbl2 b
+  on subq2.key = b.key
+PREHOOK: type: QUERY
+PREHOOK: Input: default@tbl1
+PREHOOK: Input: default@tbl2
+#### A masked pattern was here ####
+POSTHOOK: query: select /*+mapjoin(subq2)*/ count(*) from 
+  (
+  select * from
+    (
+      select a.key as key, a.value as value from tbl1 a where key < 8
+    ) subq1 
+  where key < 6
+  ) subq2
+  join tbl2 b
+  on subq2.key = b.key
+POSTHOOK: type: QUERY
+POSTHOOK: Input: default@tbl1
+POSTHOOK: Input: default@tbl2
+#### A masked pattern was here ####
+POSTHOOK: Lineage: tbl1.key EXPRESSION [(src)src.FieldSchema(name:key, type:string, comment:default), ]
+POSTHOOK: Lineage: tbl1.value SIMPLE [(src)src.FieldSchema(name:value, type:string, comment:default), ]
+POSTHOOK: Lineage: tbl2.key EXPRESSION [(src)src.FieldSchema(name:key, type:string, comment:default), ]
+POSTHOOK: Lineage: tbl2.value SIMPLE [(src)src.FieldSchema(name:value, type:string, comment:default), ]
+20
+PREHOOK: query: -- Both the big table and the small table are nested sub-queries i.e more then 1 level of sub-query.
+-- The join should be converted to a sort-merge join
+explain
+select /*+mapjoin(subq2)*/ count(*) from 
+  (
+  select * from
+    (
+      select a.key as key, a.value as value from tbl1 a where key < 8
+    ) subq1 
+  where key < 6
+  ) subq2
+  join
+  (
+  select * from
+    (
+      select a.key as key, a.value as value from tbl1 a where key < 8
+    ) subq3 
+  where key < 6
+  ) subq4
+  on subq2.key = subq4.key
+PREHOOK: type: QUERY
+POSTHOOK: query: -- Both the big table and the small table are nested sub-queries i.e more then 1 level of sub-query.
+-- The join should be converted to a sort-merge join
+explain
+select /*+mapjoin(subq2)*/ count(*) from 
+  (
+  select * from
+    (
+      select a.key as key, a.value as value from tbl1 a where key < 8
+    ) subq1 
+  where key < 6
+  ) subq2
+  join
+  (
+  select * from
+    (
+      select a.key as key, a.value as value from tbl1 a where key < 8
+    ) subq3 
+  where key < 6
+  ) subq4
+  on subq2.key = subq4.key
+POSTHOOK: type: QUERY
+POSTHOOK: Lineage: tbl1.key EXPRESSION [(src)src.FieldSchema(name:key, type:string, comment:default), ]
+POSTHOOK: Lineage: tbl1.value SIMPLE [(src)src.FieldSchema(name:value, type:string, comment:default), ]
+POSTHOOK: Lineage: tbl2.key EXPRESSION [(src)src.FieldSchema(name:key, type:string, comment:default), ]
+POSTHOOK: Lineage: tbl2.value SIMPLE [(src)src.FieldSchema(name:value, type:string, comment:default), ]
+ABSTRACT SYNTAX TREE:
+  (TOK_QUERY (TOK_FROM (TOK_JOIN (TOK_SUBQUERY (TOK_QUERY (TOK_FROM (TOK_SUBQUERY (TOK_QUERY (TOK_FROM (TOK_TABREF (TOK_TABNAME tbl1) a)) (TOK_INSERT (TOK_DESTINATION (TOK_DIR TOK_TMP_FILE)) (TOK_SELECT (TOK_SELEXPR (. (TOK_TABLE_OR_COL a) key) key) (TOK_SELEXPR (. (TOK_TABLE_OR_COL a) value) value)) (TOK_WHERE (< (TOK_TABLE_OR_COL key) 8)))) subq1)) (TOK_INSERT (TOK_DESTINATION (TOK_DIR TOK_TMP_FILE)) (TOK_SELECT (TOK_SELEXPR TOK_ALLCOLREF)) (TOK_WHERE (< (TOK_TABLE_OR_COL key) 6)))) subq2) (TOK_SUBQUERY (TOK_QUERY (TOK_FROM (TOK_SUBQUERY (TOK_QUERY (TOK_FROM (TOK_TABREF (TOK_TABNAME tbl1) a)) (TOK_INSERT (TOK_DESTINATION (TOK_DIR TOK_TMP_FILE)) (TOK_SELECT (TOK_SELEXPR (. (TOK_TABLE_OR_COL a) key) key) (TOK_SELEXPR (. (TOK_TABLE_OR_COL a) value) value)) (TOK_WHERE (< (TOK_TABLE_OR_COL key) 8)))) subq3)) (TOK_INSERT (TOK_DESTINATION (TOK_DIR TOK_TMP_FILE)) (TOK_SELECT (TOK_SELEXPR TOK_ALLCOLREF)) (TOK_WHERE (< (TOK_TABLE_OR_COL key) 6)))) subq4) (= (. (TOK_TABLE_OR_COL subq
 2) key) (. (TOK_TABLE_OR_COL subq4) key)))) (TOK_INSERT (TOK_DESTINATION (TOK_DIR TOK_TMP_FILE)) (TOK_SELECT (TOK_HINTLIST (TOK_HINT TOK_MAPJOIN (TOK_HINTARGLIST subq2))) (TOK_SELEXPR (TOK_FUNCTIONSTAR count)))))
+
+STAGE DEPENDENCIES:
+  Stage-1 is a root stage
+  Stage-2 depends on stages: Stage-1
+  Stage-0 is a root stage
+
+STAGE PLANS:
+  Stage: Stage-1
+    Map Reduce
+      Alias -> Map Operator Tree:
+        subq4:subq3:a 
+          TableScan
+            alias: a
+            Filter Operator
+              predicate:
+                  expr: ((key < 8) and (key < 6))
+                  type: boolean
+              Select Operator
+                expressions:
+                      expr: key
+                      type: int
+                outputColumnNames: _col0
+                Select Operator
+                  expressions:
+                        expr: _col0
+                        type: int
+                  outputColumnNames: _col0
+                  Sorted Merge Bucket Map Join Operator
+                    condition map:
+                         Inner Join 0 to 1
+                    condition expressions:
+                      0 
+                      1 
+                    handleSkewJoin: false
+                    keys:
+                      0 [Column[_col0]]
+                      1 [Column[_col0]]
+                    Position of Big Table: 1
+                    File Output Operator
+                      compressed: false
+                      GlobalTableId: 0
+                      table:
+                          input format: org.apache.hadoop.mapred.SequenceFileInputFormat
+                          output format: org.apache.hadoop.hive.ql.io.HiveSequenceFileOutputFormat
+
+  Stage: Stage-2
+    Map Reduce
+      Alias -> Map Operator Tree:
+#### A masked pattern was here ####
+          Select Operator
+            Select Operator
+              Group By Operator
+                aggregations:
+                      expr: count()
+                bucketGroup: false
+                mode: hash
+                outputColumnNames: _col0
+                Reduce Output Operator
+                  sort order: 
+                  tag: -1
+                  value expressions:
+                        expr: _col0
+                        type: bigint
+      Reduce Operator Tree:
+        Group By Operator
+          aggregations:
+                expr: count(VALUE._col0)
+          bucketGroup: false
+          mode: mergepartial
+          outputColumnNames: _col0
+          Select Operator
+            expressions:
+                  expr: _col0
+                  type: bigint
+            outputColumnNames: _col0
+            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: select /*+mapjoin(subq2)*/ count(*) from 
+  (
+  select * from
+    (
+      select a.key as key, a.value as value from tbl1 a where key < 8
+    ) subq1 
+  where key < 6
+  ) subq2
+  join
+  (
+  select * from
+    (
+      select a.key as key, a.value as value from tbl1 a where key < 8
+    ) subq3 
+  where key < 6
+  ) subq4
+  on subq2.key = subq4.key
+PREHOOK: type: QUERY
+PREHOOK: Input: default@tbl1
+#### A masked pattern was here ####
+POSTHOOK: query: select /*+mapjoin(subq2)*/ count(*) from 
+  (
+  select * from
+    (
+      select a.key as key, a.value as value from tbl1 a where key < 8
+    ) subq1 
+  where key < 6
+  ) subq2
+  join
+  (
+  select * from
+    (
+      select a.key as key, a.value as value from tbl1 a where key < 8
+    ) subq3 
+  where key < 6
+  ) subq4
+  on subq2.key = subq4.key
+POSTHOOK: type: QUERY
+POSTHOOK: Input: default@tbl1
+#### A masked pattern was here ####
+POSTHOOK: Lineage: tbl1.key EXPRESSION [(src)src.FieldSchema(name:key, type:string, comment:default), ]
+POSTHOOK: Lineage: tbl1.value SIMPLE [(src)src.FieldSchema(name:value, type:string, comment:default), ]
+POSTHOOK: Lineage: tbl2.key EXPRESSION [(src)src.FieldSchema(name:key, type:string, comment:default), ]
+POSTHOOK: Lineage: tbl2.value SIMPLE [(src)src.FieldSchema(name:value, type:string, comment:default), ]
+20
+PREHOOK: query: -- The subquery itself is being map-joined. Since the sub-query only contains selects and filters and the join key
+-- is not getting modified, it should be converted to a sort-merge join. Note that the sub-query modifies one 
+-- item, but that is not part of the join key.
+explain
+select /*+mapjoin(subq1)*/ count(*) from 
+  (select a.key as key, concat(a.value, a.value) as value from tbl1 a where key < 8) subq1 
+    join
+  (select a.key as key, concat(a.value, a.value) as value from tbl2 a where key < 8) subq2
+  on subq1.key = subq2.key
+PREHOOK: type: QUERY
+POSTHOOK: query: -- The subquery itself is being map-joined. Since the sub-query only contains selects and filters and the join key
+-- is not getting modified, it should be converted to a sort-merge join. Note that the sub-query modifies one 
+-- item, but that is not part of the join key.
+explain
+select /*+mapjoin(subq1)*/ count(*) from 
+  (select a.key as key, concat(a.value, a.value) as value from tbl1 a where key < 8) subq1 
+    join
+  (select a.key as key, concat(a.value, a.value) as value from tbl2 a where key < 8) subq2
+  on subq1.key = subq2.key
+POSTHOOK: type: QUERY
+POSTHOOK: Lineage: tbl1.key EXPRESSION [(src)src.FieldSchema(name:key, type:string, comment:default), ]
+POSTHOOK: Lineage: tbl1.value SIMPLE [(src)src.FieldSchema(name:value, type:string, comment:default), ]
+POSTHOOK: Lineage: tbl2.key EXPRESSION [(src)src.FieldSchema(name:key, type:string, comment:default), ]
+POSTHOOK: Lineage: tbl2.value SIMPLE [(src)src.FieldSchema(name:value, type:string, comment:default), ]
+ABSTRACT SYNTAX TREE:
+  (TOK_QUERY (TOK_FROM (TOK_JOIN (TOK_SUBQUERY (TOK_QUERY (TOK_FROM (TOK_TABREF (TOK_TABNAME tbl1) a)) (TOK_INSERT (TOK_DESTINATION (TOK_DIR TOK_TMP_FILE)) (TOK_SELECT (TOK_SELEXPR (. (TOK_TABLE_OR_COL a) key) key) (TOK_SELEXPR (TOK_FUNCTION concat (. (TOK_TABLE_OR_COL a) value) (. (TOK_TABLE_OR_COL a) value)) value)) (TOK_WHERE (< (TOK_TABLE_OR_COL key) 8)))) subq1) (TOK_SUBQUERY (TOK_QUERY (TOK_FROM (TOK_TABREF (TOK_TABNAME tbl2) a)) (TOK_INSERT (TOK_DESTINATION (TOK_DIR TOK_TMP_FILE)) (TOK_SELECT (TOK_SELEXPR (. (TOK_TABLE_OR_COL a) key) key) (TOK_SELEXPR (TOK_FUNCTION concat (. (TOK_TABLE_OR_COL a) value) (. (TOK_TABLE_OR_COL a) value)) value)) (TOK_WHERE (< (TOK_TABLE_OR_COL key) 8)))) subq2) (= (. (TOK_TABLE_OR_COL subq1) key) (. (TOK_TABLE_OR_COL subq2) key)))) (TOK_INSERT (TOK_DESTINATION (TOK_DIR TOK_TMP_FILE)) (TOK_SELECT (TOK_HINTLIST (TOK_HINT TOK_MAPJOIN (TOK_HINTARGLIST subq1))) (TOK_SELEXPR (TOK_FUNCTIONSTAR count)))))
+
+STAGE DEPENDENCIES:
+  Stage-1 is a root stage
+  Stage-2 depends on stages: Stage-1
+  Stage-0 is a root stage
+
+STAGE PLANS:
+  Stage: Stage-1
+    Map Reduce
+      Alias -> Map Operator Tree:
+        subq2:a 
+          TableScan
+            alias: a
+            Filter Operator
+              predicate:
+                  expr: (key < 8)
+                  type: boolean
+              Select Operator
+                expressions:
+                      expr: key
+                      type: int
+                outputColumnNames: _col0
+                Sorted Merge Bucket Map Join Operator
+                  condition map:
+                       Inner Join 0 to 1
+                  condition expressions:
+                    0 
+                    1 
+                  handleSkewJoin: false
+                  keys:
+                    0 [Column[_col0]]
+                    1 [Column[_col0]]
+                  Position of Big Table: 1
+                  File Output Operator
+                    compressed: false
+                    GlobalTableId: 0
+                    table:
+                        input format: org.apache.hadoop.mapred.SequenceFileInputFormat
+                        output format: org.apache.hadoop.hive.ql.io.HiveSequenceFileOutputFormat
+
+  Stage: Stage-2
+    Map Reduce
+      Alias -> Map Operator Tree:
+#### A masked pattern was here ####
+          Select Operator
+            Select Operator
+              Group By Operator
+                aggregations:
+                      expr: count()
+                bucketGroup: false
+                mode: hash
+                outputColumnNames: _col0
+                Reduce Output Operator
+                  sort order: 
+                  tag: -1
+                  value expressions:
+                        expr: _col0
+                        type: bigint
+      Reduce Operator Tree:
+        Group By Operator
+          aggregations:
+                expr: count(VALUE._col0)
+          bucketGroup: false
+          mode: mergepartial
+          outputColumnNames: _col0
+          Select Operator
+            expressions:
+                  expr: _col0
+                  type: bigint
+            outputColumnNames: _col0
+            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: select /*+mapjoin(subq1)*/ count(*) from 
+  (select a.key as key, concat(a.value, a.value) as value from tbl1 a where key < 8) subq1 
+    join
+  (select a.key as key, concat(a.value, a.value) as value from tbl2 a where key < 8) subq2
+  on subq1.key = subq2.key
+PREHOOK: type: QUERY
+PREHOOK: Input: default@tbl1
+PREHOOK: Input: default@tbl2
+#### A masked pattern was here ####
+POSTHOOK: query: select /*+mapjoin(subq1)*/ count(*) from 
+  (select a.key as key, concat(a.value, a.value) as value from tbl1 a where key < 8) subq1 
+    join
+  (select a.key as key, concat(a.value, a.value) as value from tbl2 a where key < 8) subq2
+  on subq1.key = subq2.key
+POSTHOOK: type: QUERY
+POSTHOOK: Input: default@tbl1
+POSTHOOK: Input: default@tbl2
+#### A masked pattern was here ####
+POSTHOOK: Lineage: tbl1.key EXPRESSION [(src)src.FieldSchema(name:key, type:string, comment:default), ]
+POSTHOOK: Lineage: tbl1.value SIMPLE [(src)src.FieldSchema(name:value, type:string, comment:default), ]
+POSTHOOK: Lineage: tbl2.key EXPRESSION [(src)src.FieldSchema(name:key, type:string, comment:default), ]
+POSTHOOK: Lineage: tbl2.value SIMPLE [(src)src.FieldSchema(name:value, type:string, comment:default), ]
+20
+PREHOOK: query: -- Since the join key is modified by the sub-query, neither sort-merge join not bucketized map-side
+-- join should be performed
+explain
+select /*+mapjoin(subq1)*/ count(*) from 
+  (select a.key +1 as key, concat(a.value, a.value) as value from tbl1 a) subq1 
+    join
+  (select a.key +1 as key, concat(a.value, a.value) as value from tbl2 a) subq2
+  on subq1.key = subq2.key
+PREHOOK: type: QUERY
+POSTHOOK: query: -- Since the join key is modified by the sub-query, neither sort-merge join not bucketized map-side
+-- join should be performed
+explain
+select /*+mapjoin(subq1)*/ count(*) from 
+  (select a.key +1 as key, concat(a.value, a.value) as value from tbl1 a) subq1 
+    join
+  (select a.key +1 as key, concat(a.value, a.value) as value from tbl2 a) subq2
+  on subq1.key = subq2.key
+POSTHOOK: type: QUERY
+POSTHOOK: Lineage: tbl1.key EXPRESSION [(src)src.FieldSchema(name:key, type:string, comment:default), ]
+POSTHOOK: Lineage: tbl1.value SIMPLE [(src)src.FieldSchema(name:value, type:string, comment:default), ]
+POSTHOOK: Lineage: tbl2.key EXPRESSION [(src)src.FieldSchema(name:key, type:string, comment:default), ]
+POSTHOOK: Lineage: tbl2.value SIMPLE [(src)src.FieldSchema(name:value, type:string, comment:default), ]
+ABSTRACT SYNTAX TREE:
+  (TOK_QUERY (TOK_FROM (TOK_JOIN (TOK_SUBQUERY (TOK_QUERY (TOK_FROM (TOK_TABREF (TOK_TABNAME tbl1) a)) (TOK_INSERT (TOK_DESTINATION (TOK_DIR TOK_TMP_FILE)) (TOK_SELECT (TOK_SELEXPR (+ (. (TOK_TABLE_OR_COL a) key) 1) key) (TOK_SELEXPR (TOK_FUNCTION concat (. (TOK_TABLE_OR_COL a) value) (. (TOK_TABLE_OR_COL a) value)) value)))) subq1) (TOK_SUBQUERY (TOK_QUERY (TOK_FROM (TOK_TABREF (TOK_TABNAME tbl2) a)) (TOK_INSERT (TOK_DESTINATION (TOK_DIR TOK_TMP_FILE)) (TOK_SELECT (TOK_SELEXPR (+ (. (TOK_TABLE_OR_COL a) key) 1) key) (TOK_SELEXPR (TOK_FUNCTION concat (. (TOK_TABLE_OR_COL a) value) (. (TOK_TABLE_OR_COL a) value)) value)))) subq2) (= (. (TOK_TABLE_OR_COL subq1) key) (. (TOK_TABLE_OR_COL subq2) key)))) (TOK_INSERT (TOK_DESTINATION (TOK_DIR TOK_TMP_FILE)) (TOK_SELECT (TOK_HINTLIST (TOK_HINT TOK_MAPJOIN (TOK_HINTARGLIST subq1))) (TOK_SELEXPR (TOK_FUNCTIONSTAR count)))))
+
+STAGE DEPENDENCIES:
+  Stage-4 is a root stage
+  Stage-1 depends on stages: Stage-4
+  Stage-2 depends on stages: Stage-1
+  Stage-0 is a root stage
+
+STAGE PLANS:
+  Stage: Stage-4
+    Map Reduce Local Work
+      Alias -> Map Local Tables:
+        subq1:a 
+          Fetch Operator
+            limit: -1
+      Alias -> Map Local Operator Tree:
+        subq1:a 
+          TableScan
+            alias: a
+            Select Operator
+              expressions:
+                    expr: (key + 1)
+                    type: int
+              outputColumnNames: _col0
+              HashTable Sink Operator
+                condition expressions:
+                  0 
+                  1 
+                handleSkewJoin: false
+                keys:
+                  0 [Column[_col0]]
+                  1 [Column[_col0]]
+                Position of Big Table: 1
+
+  Stage: Stage-1
+    Map Reduce
+      Alias -> Map Operator Tree:
+        subq2:a 
+          TableScan
+            alias: a
+            Select Operator
+              expressions:
+                    expr: (key + 1)
+                    type: int
+              outputColumnNames: _col0
+              Map Join Operator
+                condition map:
+                     Inner Join 0 to 1
+                condition expressions:
+                  0 
+                  1 
+                handleSkewJoin: false
+                keys:
+                  0 [Column[_col0]]
+                  1 [Column[_col0]]
+                Position of Big Table: 1
+                File Output Operator
+                  compressed: false
+                  GlobalTableId: 0
+                  table:
+                      input format: org.apache.hadoop.mapred.SequenceFileInputFormat
+                      output format: org.apache.hadoop.hive.ql.io.HiveSequenceFileOutputFormat
+      Local Work:
+        Map Reduce Local Work
+
+  Stage: Stage-2
+    Map Reduce
+      Alias -> Map Operator Tree:
+#### A masked pattern was here ####
+          Select Operator
+            Select Operator
+              Group By Operator
+                aggregations:
+                      expr: count()
+                bucketGroup: false
+                mode: hash
+                outputColumnNames: _col0
+                Reduce Output Operator
+                  sort order: 
+                  tag: -1
+                  value expressions:
+                        expr: _col0
+                        type: bigint
+      Reduce Operator Tree:
+        Group By Operator
+          aggregations:
+                expr: count(VALUE._col0)
+          bucketGroup: false
+          mode: mergepartial
+          outputColumnNames: _col0
+          Select Operator
+            expressions:
+                  expr: _col0
+                  type: bigint
+            outputColumnNames: _col0
+            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: select /*+mapjoin(subq1)*/ count(*) from 
+  (select a.key +1 as key, concat(a.value, a.value) as value from tbl1 a) subq1 
+    join
+  (select a.key +1 as key, concat(a.value, a.value) as value from tbl2 a) subq2
+  on subq1.key = subq2.key
+PREHOOK: type: QUERY
+PREHOOK: Input: default@tbl1
+PREHOOK: Input: default@tbl2
+#### A masked pattern was here ####
+POSTHOOK: query: select /*+mapjoin(subq1)*/ count(*) from 
+  (select a.key +1 as key, concat(a.value, a.value) as value from tbl1 a) subq1 
+    join
+  (select a.key +1 as key, concat(a.value, a.value) as value from tbl2 a) subq2
+  on subq1.key = subq2.key
+POSTHOOK: type: QUERY
+POSTHOOK: Input: default@tbl1
+POSTHOOK: Input: default@tbl2
+#### A masked pattern was here ####
+POSTHOOK: Lineage: tbl1.key EXPRESSION [(src)src.FieldSchema(name:key, type:string, comment:default), ]
+POSTHOOK: Lineage: tbl1.value SIMPLE [(src)src.FieldSchema(name:value, type:string, comment:default), ]
+POSTHOOK: Lineage: tbl2.key EXPRESSION [(src)src.FieldSchema(name:key, type:string, comment:default), ]
+POSTHOOK: Lineage: tbl2.value SIMPLE [(src)src.FieldSchema(name:value, type:string, comment:default), ]
+22
+PREHOOK: query: -- The small table is a sub-query and the big table is not.
+-- It should be converted to a sort-merge join.
+explain
+select /*+mapjoin(subq1)*/ count(*) from 
+  (select a.key as key, a.value as value from tbl1 a where key < 6) subq1 
+    join tbl2 a on subq1.key = a.key
+PREHOOK: type: QUERY
+POSTHOOK: query: -- The small table is a sub-query and the big table is not.
+-- It should be converted to a sort-merge join.
+explain
+select /*+mapjoin(subq1)*/ count(*) from 
+  (select a.key as key, a.value as value from tbl1 a where key < 6) subq1 
+    join tbl2 a on subq1.key = a.key
+POSTHOOK: type: QUERY
+POSTHOOK: Lineage: tbl1.key EXPRESSION [(src)src.FieldSchema(name:key, type:string, comment:default), ]
+POSTHOOK: Lineage: tbl1.value SIMPLE [(src)src.FieldSchema(name:value, type:string, comment:default), ]
+POSTHOOK: Lineage: tbl2.key EXPRESSION [(src)src.FieldSchema(name:key, type:string, comment:default), ]
+POSTHOOK: Lineage: tbl2.value SIMPLE [(src)src.FieldSchema(name:value, type:string, comment:default), ]
+ABSTRACT SYNTAX TREE:
+  (TOK_QUERY (TOK_FROM (TOK_JOIN (TOK_SUBQUERY (TOK_QUERY (TOK_FROM (TOK_TABREF (TOK_TABNAME tbl1) a)) (TOK_INSERT (TOK_DESTINATION (TOK_DIR TOK_TMP_FILE)) (TOK_SELECT (TOK_SELEXPR (. (TOK_TABLE_OR_COL a) key) key) (TOK_SELEXPR (. (TOK_TABLE_OR_COL a) value) value)) (TOK_WHERE (< (TOK_TABLE_OR_COL key) 6)))) subq1) (TOK_TABREF (TOK_TABNAME tbl2) a) (= (. (TOK_TABLE_OR_COL subq1) key) (. (TOK_TABLE_OR_COL a) key)))) (TOK_INSERT (TOK_DESTINATION (TOK_DIR TOK_TMP_FILE)) (TOK_SELECT (TOK_HINTLIST (TOK_HINT TOK_MAPJOIN (TOK_HINTARGLIST subq1))) (TOK_SELEXPR (TOK_FUNCTIONSTAR count)))))
+
+STAGE DEPENDENCIES:
+  Stage-1 is a root stage
+  Stage-2 depends on stages: Stage-1
+  Stage-0 is a root stage
+
+STAGE PLANS:
+  Stage: Stage-1
+    Map Reduce
+      Alias -> Map Operator Tree:
+        a 
+          TableScan
+            alias: a
+            Sorted Merge Bucket Map Join Operator
+              condition map:
+                   Inner Join 0 to 1
+              condition expressions:
+                0 
+                1 
+              handleSkewJoin: false
+              keys:
+                0 [Column[_col0]]
+                1 [Column[key]]
+              Position of Big Table: 1
+              File Output Operator
+                compressed: false
+                GlobalTableId: 0
+                table:
+                    input format: org.apache.hadoop.mapred.SequenceFileInputFormat
+                    output format: org.apache.hadoop.hive.ql.io.HiveSequenceFileOutputFormat
+
+  Stage: Stage-2
+    Map Reduce
+      Alias -> Map Operator Tree:
+#### A masked pattern was here ####
+          Select Operator
+            Select Operator
+              Group By Operator
+                aggregations:
+                      expr: count()
+                bucketGroup: false
+                mode: hash
+                outputColumnNames: _col0
+                Reduce Output Operator
+                  sort order: 
+                  tag: -1
+                  value expressions:
+                        expr: _col0
+                        type: bigint
+      Reduce Operator Tree:
+        Group By Operator
+          aggregations:
+                expr: count(VALUE._col0)
+          bucketGroup: false
+          mode: mergepartial
+          outputColumnNames: _col0
+          Select Operator
+            expressions:
+                  expr: _col0
+                  type: bigint
+            outputColumnNames: _col0
+            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: select /*+mapjoin(subq1)*/ count(*) from 
+  (select a.key as key, a.value as value from tbl1 a where key < 6) subq1 
+    join tbl2 a on subq1.key = a.key
+PREHOOK: type: QUERY
+PREHOOK: Input: default@tbl1
+PREHOOK: Input: default@tbl2
+#### A masked pattern was here ####
+POSTHOOK: query: select /*+mapjoin(subq1)*/ count(*) from 
+  (select a.key as key, a.value as value from tbl1 a where key < 6) subq1 
+    join tbl2 a on subq1.key = a.key
+POSTHOOK: type: QUERY
+POSTHOOK: Input: default@tbl1
+POSTHOOK: Input: default@tbl2
+#### A masked pattern was here ####
+POSTHOOK: Lineage: tbl1.key EXPRESSION [(src)src.FieldSchema(name:key, type:string, comment:default), ]
+POSTHOOK: Lineage: tbl1.value SIMPLE [(src)src.FieldSchema(name:value, type:string, comment:default), ]
+POSTHOOK: Lineage: tbl2.key EXPRESSION [(src)src.FieldSchema(name:key, type:string, comment:default), ]
+POSTHOOK: Lineage: tbl2.value SIMPLE [(src)src.FieldSchema(name:value, type:string, comment:default), ]
+20
+PREHOOK: query: -- The big table is a sub-query and the small table is not.
+-- It should be converted to a sort-merge join.
+explain
+select /*+mapjoin(a)*/ count(*) from 
+  (select a.key as key, a.value as value from tbl1 a where key < 6) subq1 
+    join tbl2 a on subq1.key = a.key
+PREHOOK: type: QUERY
+POSTHOOK: query: -- The big table is a sub-query and the small table is not.
+-- It should be converted to a sort-merge join.
+explain
+select /*+mapjoin(a)*/ count(*) from 
+  (select a.key as key, a.value as value from tbl1 a where key < 6) subq1 
+    join tbl2 a on subq1.key = a.key
+POSTHOOK: type: QUERY
+POSTHOOK: Lineage: tbl1.key EXPRESSION [(src)src.FieldSchema(name:key, type:string, comment:default), ]
+POSTHOOK: Lineage: tbl1.value SIMPLE [(src)src.FieldSchema(name:value, type:string, comment:default), ]
+POSTHOOK: Lineage: tbl2.key EXPRESSION [(src)src.FieldSchema(name:key, type:string, comment:default), ]
+POSTHOOK: Lineage: tbl2.value SIMPLE [(src)src.FieldSchema(name:value, type:string, comment:default), ]
+ABSTRACT SYNTAX TREE:
+  (TOK_QUERY (TOK_FROM (TOK_JOIN (TOK_SUBQUERY (TOK_QUERY (TOK_FROM (TOK_TABREF (TOK_TABNAME tbl1) a)) (TOK_INSERT (TOK_DESTINATION (TOK_DIR TOK_TMP_FILE)) (TOK_SELECT (TOK_SELEXPR (. (TOK_TABLE_OR_COL a) key) key) (TOK_SELEXPR (. (TOK_TABLE_OR_COL a) value) value)) (TOK_WHERE (< (TOK_TABLE_OR_COL key) 6)))) subq1) (TOK_TABREF (TOK_TABNAME tbl2) a) (= (. (TOK_TABLE_OR_COL subq1) key) (. (TOK_TABLE_OR_COL a) key)))) (TOK_INSERT (TOK_DESTINATION (TOK_DIR TOK_TMP_FILE)) (TOK_SELECT (TOK_HINTLIST (TOK_HINT TOK_MAPJOIN (TOK_HINTARGLIST a))) (TOK_SELEXPR (TOK_FUNCTIONSTAR count)))))
+
+STAGE DEPENDENCIES:
+  Stage-1 is a root stage
+  Stage-2 depends on stages: Stage-1
+  Stage-0 is a root stage
+
+STAGE PLANS:
+  Stage: Stage-1
+    Map Reduce
+      Alias -> Map Operator Tree:
+        subq1:a 
+          TableScan
+            alias: a
+            Filter Operator
+              predicate:
+                  expr: (key < 6)
+                  type: boolean
+              Select Operator
+                expressions:
+                      expr: key
+                      type: int
+                outputColumnNames: _col0
+                Sorted Merge Bucket Map Join Operator
+                  condition map:
+                       Inner Join 0 to 1
+                  condition expressions:
+                    0 
+                    1 
+                  handleSkewJoin: false
+                  keys:
+                    0 [Column[_col0]]
+                    1 [Column[key]]
+                  Position of Big Table: 0
+                  File Output Operator
+                    compressed: false
+                    GlobalTableId: 0
+                    table:
+                        input format: org.apache.hadoop.mapred.SequenceFileInputFormat
+                        output format: org.apache.hadoop.hive.ql.io.HiveSequenceFileOutputFormat
+
+  Stage: Stage-2
+    Map Reduce
+      Alias -> Map Operator Tree:
+#### A masked pattern was here ####
+          Select Operator
+            Select Operator
+              Group By Operator
+                aggregations:
+                      expr: count()
+                bucketGroup: false
+                mode: hash
+                outputColumnNames: _col0
+                Reduce Output Operator
+                  sort order: 
+                  tag: -1
+                  value expressions:
+                        expr: _col0
+                        type: bigint
+      Reduce Operator Tree:
+        Group By Operator
+          aggregations:
+                expr: count(VALUE._col0)
+          bucketGroup: false
+          mode: mergepartial
+          outputColumnNames: _col0
+          Select Operator
+            expressions:
+                  expr: _col0
+                  type: bigint
+            outputColumnNames: _col0
+            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: select /*+mapjoin(a)*/ count(*) from 
+  (select a.key as key, a.value as value from tbl1 a where key < 6) subq1 
+    join tbl2 a on subq1.key = a.key
+PREHOOK: type: QUERY
+PREHOOK: Input: default@tbl1
+PREHOOK: Input: default@tbl2
+#### A masked pattern was here ####
+POSTHOOK: query: select /*+mapjoin(a)*/ count(*) from 
+  (select a.key as key, a.value as value from tbl1 a where key < 6) subq1 
+    join tbl2 a on subq1.key = a.key
+POSTHOOK: type: QUERY
+POSTHOOK: Input: default@tbl1
+POSTHOOK: Input: default@tbl2
+#### A masked pattern was here ####
+POSTHOOK: Lineage: tbl1.key EXPRESSION [(src)src.FieldSchema(name:key, type:string, comment:default), ]
+POSTHOOK: Lineage: tbl1.value SIMPLE [(src)src.FieldSchema(name:value, type:string, comment:default), ]
+POSTHOOK: Lineage: tbl2.key EXPRESSION [(src)src.FieldSchema(name:key, type:string, comment:default), ]
+POSTHOOK: Lineage: tbl2.value SIMPLE [(src)src.FieldSchema(name:value, type:string, comment:default), ]
+20
+PREHOOK: query: -- There are more than 2 inputs to the join, all of them being sub-queries. 
+-- It should be converted to to a sort-merge join
+explain
+select /*+mapjoin(subq1, subq2)*/ count(*) from 
+  (select a.key as key, a.value as value from tbl1 a where key < 6) subq1 
+    join
+  (select a.key as key, a.value as value from tbl2 a where key < 6) subq2
+  on (subq1.key = subq2.key)
+    join
+  (select a.key as key, a.value as value from tbl2 a where key < 6) subq3
+  on (subq1.key = subq3.key)
+PREHOOK: type: QUERY
+POSTHOOK: query: -- There are more than 2 inputs to the join, all of them being sub-queries. 
+-- It should be converted to to a sort-merge join
+explain
+select /*+mapjoin(subq1, subq2)*/ count(*) from 
+  (select a.key as key, a.value as value from tbl1 a where key < 6) subq1 
+    join
+  (select a.key as key, a.value as value from tbl2 a where key < 6) subq2
+  on (subq1.key = subq2.key)
+    join
+  (select a.key as key, a.value as value from tbl2 a where key < 6) subq3
+  on (subq1.key = subq3.key)
+POSTHOOK: type: QUERY
+POSTHOOK: Lineage: tbl1.key EXPRESSION [(src)src.FieldSchema(name:key, type:string, comment:default), ]
+POSTHOOK: Lineage: tbl1.value SIMPLE [(src)src.FieldSchema(name:value, type:string, comment:default), ]
+POSTHOOK: Lineage: tbl2.key EXPRESSION [(src)src.FieldSchema(name:key, type:string, comment:default), ]
+POSTHOOK: Lineage: tbl2.value SIMPLE [(src)src.FieldSchema(name:value, type:string, comment:default), ]
+ABSTRACT SYNTAX TREE:
+  (TOK_QUERY (TOK_FROM (TOK_JOIN (TOK_JOIN (TOK_SUBQUERY (TOK_QUERY (TOK_FROM (TOK_TABREF (TOK_TABNAME tbl1) a)) (TOK_INSERT (TOK_DESTINATION (TOK_DIR TOK_TMP_FILE)) (TOK_SELECT (TOK_SELEXPR (. (TOK_TABLE_OR_COL a) key) key) (TOK_SELEXPR (. (TOK_TABLE_OR_COL a) value) value)) (TOK_WHERE (< (TOK_TABLE_OR_COL key) 6)))) subq1) (TOK_SUBQUERY (TOK_QUERY (TOK_FROM (TOK_TABREF (TOK_TABNAME tbl2) a)) (TOK_INSERT (TOK_DESTINATION (TOK_DIR TOK_TMP_FILE)) (TOK_SELECT (TOK_SELEXPR (. (TOK_TABLE_OR_COL a) key) key) (TOK_SELEXPR (. (TOK_TABLE_OR_COL a) value) value)) (TOK_WHERE (< (TOK_TABLE_OR_COL key) 6)))) subq2) (= (. (TOK_TABLE_OR_COL subq1) key) (. (TOK_TABLE_OR_COL subq2) key))) (TOK_SUBQUERY (TOK_QUERY (TOK_FROM (TOK_TABREF (TOK_TABNAME tbl2) a)) (TOK_INSERT (TOK_DESTINATION (TOK_DIR TOK_TMP_FILE)) (TOK_SELECT (TOK_SELEXPR (. (TOK_TABLE_OR_COL a) key) key) (TOK_SELEXPR (. (TOK_TABLE_OR_COL a) value) value)) (TOK_WHERE (< (TOK_TABLE_OR_COL key) 6)))) subq3) (= (. (TOK_TABLE_OR_COL
  subq1) key) (. (TOK_TABLE_OR_COL subq3) key)))) (TOK_INSERT (TOK_DESTINATION (TOK_DIR TOK_TMP_FILE)) (TOK_SELECT (TOK_HINTLIST (TOK_HINT TOK_MAPJOIN (TOK_HINTARGLIST subq1 subq2))) (TOK_SELEXPR (TOK_FUNCTIONSTAR count)))))
+
+STAGE DEPENDENCIES:
+  Stage-1 is a root stage
+  Stage-2 depends on stages: Stage-1
+  Stage-0 is a root stage
+
+STAGE PLANS:
+  Stage: Stage-1
+    Map Reduce
+      Alias -> Map Operator Tree:
+        subq3:a 
+          TableScan
+            alias: a
+            Filter Operator
+              predicate:
+                  expr: (key < 6)
+                  type: boolean
+              Select Operator
+                expressions:
+                      expr: key
+                      type: int
+                outputColumnNames: _col0
+                Sorted Merge Bucket Map Join Operator
+                  condition map:
+                       Inner Join 0 to 1
+                       Inner Join 0 to 2
+                  condition expressions:
+                    0 
+                    1 
+                    2 
+                  handleSkewJoin: false
+                  keys:
+                    0 [Column[_col0]]
+                    1 [Column[_col0]]
+                    2 [Column[_col0]]
+                  Position of Big Table: 2
+                  File Output Operator
+                    compressed: false
+                    GlobalTableId: 0
+                    table:
+                        input format: org.apache.hadoop.mapred.SequenceFileInputFormat
+                        output format: org.apache.hadoop.hive.ql.io.HiveSequenceFileOutputFormat
+
+  Stage: Stage-2
+    Map Reduce
+      Alias -> Map Operator Tree:
+#### A masked pattern was here ####
+          Select Operator
+            Select Operator
+              Group By Operator
+                aggregations:
+                      expr: count()
+                bucketGroup: false
+                mode: hash
+                outputColumnNames: _col0
+                Reduce Output Operator
+                  sort order: 
+                  tag: -1
+                  value expressions:
+                        expr: _col0
+                        type: bigint
+      Reduce Operator Tree:
+        Group By Operator
+          aggregations:
+                expr: count(VALUE._col0)
+          bucketGroup: false
+          mode: mergepartial
+          outputColumnNames: _col0
+          Select Operator
+            expressions:
+                  expr: _col0
+                  type: bigint
+            outputColumnNames: _col0
+            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: select /*+mapjoin(subq1, subq2)*/ count(*) from 
+  (select a.key as key, a.value as value from tbl1 a where key < 6) subq1 
+    join
+  (select a.key as key, a.value as value from tbl2 a where key < 6) subq2
+  on subq1.key = subq2.key
+    join
+  (select a.key as key, a.value as value from tbl2 a where key < 6) subq3
+  on (subq1.key = subq3.key)
+PREHOOK: type: QUERY
+PREHOOK: Input: default@tbl1
+PREHOOK: Input: default@tbl2
+#### A masked pattern was here ####
+POSTHOOK: query: select /*+mapjoin(subq1, subq2)*/ count(*) from 
+  (select a.key as key, a.value as value from tbl1 a where key < 6) subq1 
+    join
+  (select a.key as key, a.value as value from tbl2 a where key < 6) subq2
+  on subq1.key = subq2.key
+    join
+  (select a.key as key, a.value as value from tbl2 a where key < 6) subq3
+  on (subq1.key = subq3.key)
+POSTHOOK: type: QUERY
+POSTHOOK: Input: default@tbl1
+POSTHOOK: Input: default@tbl2
+#### A masked pattern was here ####
+POSTHOOK: Lineage: tbl1.key EXPRESSION [(src)src.FieldSchema(name:key, type:string, comment:default), ]
+POSTHOOK: Lineage: tbl1.value SIMPLE [(src)src.FieldSchema(name:value, type:string, comment:default), ]
+POSTHOOK: Lineage: tbl2.key EXPRESSION [(src)src.FieldSchema(name:key, type:string, comment:default), ]
+POSTHOOK: Lineage: tbl2.value SIMPLE [(src)src.FieldSchema(name:value, type:string, comment:default), ]
+56
+PREHOOK: query: -- The mapjoin is being performed on a nested sub-query, and an aggregation is performed after that.
+-- The join should be converted to a sort-merge join
+explain
+select count(*) from (
+  select /*+mapjoin(subq2)*/ subq2.key as key, subq2.value as value1, b.value as value2 from
+  (
+    select * from
+    (
+      select a.key as key, a.value as value from tbl1 a where key < 8
+    ) subq1
+    where key < 6
+  ) subq2
+join tbl2 b
+on subq2.key = b.key) a
+PREHOOK: type: QUERY
+POSTHOOK: query: -- The mapjoin is being performed on a nested sub-query, and an aggregation is performed after that.
+-- The join should be converted to a sort-merge join
+explain
+select count(*) from (
+  select /*+mapjoin(subq2)*/ subq2.key as key, subq2.value as value1, b.value as value2 from
+  (
+    select * from
+    (
+      select a.key as key, a.value as value from tbl1 a where key < 8
+    ) subq1
+    where key < 6
+  ) subq2
+join tbl2 b
+on subq2.key = b.key) a
+POSTHOOK: type: QUERY
+POSTHOOK: Lineage: tbl1.key EXPRESSION [(src)src.FieldSchema(name:key, type:string, comment:default), ]
+POSTHOOK: Lineage: tbl1.value SIMPLE [(src)src.FieldSchema(name:value, type:string, comment:default), ]
+POSTHOOK: Lineage: tbl2.key EXPRESSION [(src)src.FieldSchema(name:key, type:string, comment:default), ]
+POSTHOOK: Lineage: tbl2.value SIMPLE [(src)src.FieldSchema(name:value, type:string, comment:default), ]
+ABSTRACT SYNTAX TREE:
+  (TOK_QUERY (TOK_FROM (TOK_SUBQUERY (TOK_QUERY (TOK_FROM (TOK_JOIN (TOK_SUBQUERY (TOK_QUERY (TOK_FROM (TOK_SUBQUERY (TOK_QUERY (TOK_FROM (TOK_TABREF (TOK_TABNAME tbl1) a)) (TOK_INSERT (TOK_DESTINATION (TOK_DIR TOK_TMP_FILE)) (TOK_SELECT (TOK_SELEXPR (. (TOK_TABLE_OR_COL a) key) key) (TOK_SELEXPR (. (TOK_TABLE_OR_COL a) value) value)) (TOK_WHERE (< (TOK_TABLE_OR_COL key) 8)))) subq1)) (TOK_INSERT (TOK_DESTINATION (TOK_DIR TOK_TMP_FILE)) (TOK_SELECT (TOK_SELEXPR TOK_ALLCOLREF)) (TOK_WHERE (< (TOK_TABLE_OR_COL key) 6)))) subq2) (TOK_TABREF (TOK_TABNAME tbl2) b) (= (. (TOK_TABLE_OR_COL subq2) key) (. (TOK_TABLE_OR_COL b) key)))) (TOK_INSERT (TOK_DESTINATION (TOK_DIR TOK_TMP_FILE)) (TOK_SELECT (TOK_HINTLIST (TOK_HINT TOK_MAPJOIN (TOK_HINTARGLIST subq2))) (TOK_SELEXPR (. (TOK_TABLE_OR_COL subq2) key) key) (TOK_SELEXPR (. (TOK_TABLE_OR_COL subq2) value) value1) (TOK_SELEXPR (. (TOK_TABLE_OR_COL b) value) value2)))) a)) (TOK_INSERT (TOK_DESTINATION (TOK_DIR TOK_TMP_FILE)) (TOK_SELE
 CT (TOK_SELEXPR (TOK_FUNCTIONSTAR count)))))
+
+STAGE DEPENDENCIES:
+  Stage-1 is a root stage
+  Stage-2 depends on stages: Stage-1
+  Stage-0 is a root stage
+
+STAGE PLANS:
+  Stage: Stage-1
+    Map Reduce
+      Alias -> Map Operator Tree:
+        a:b 
+          TableScan
+            alias: b
+            Sorted Merge Bucket Map Join Operator
+              condition map:
+                   Inner Join 0 to 1
+              condition expressions:
+                0 
+                1 
+              handleSkewJoin: false
+              keys:
+                0 [Column[_col0]]
+                1 [Column[key]]
+              Position of Big Table: 1
+              File Output Operator
+                compressed: false
+                GlobalTableId: 0
+                table:
+                    input format: org.apache.hadoop.mapred.SequenceFileInputFormat
+                    output format: org.apache.hadoop.hive.ql.io.HiveSequenceFileOutputFormat
+
+  Stage: Stage-2
+    Map Reduce
+      Alias -> Map Operator Tree:
+#### A masked pattern was here ####
+          Select Operator
+            Select Operator
+              Select Operator
+                Group By Operator
+                  aggregations:
+                        expr: count()
+                  bucketGroup: false
+                  mode: hash
+                  outputColumnNames: _col0
+                  Reduce Output Operator
+                    sort order: 
+                    tag: -1
+                    value expressions:
+                          expr: _col0
+                          type: bigint
+      Reduce Operator Tree:
+        Group By Operator
+          aggregations:
+                expr: count(VALUE._col0)
+          bucketGroup: false
+          mode: mergepartial
+          outputColumnNames: _col0
+          Select Operator
+            expressions:
+                  expr: _col0
+                  type: bigint
+            outputColumnNames: _col0
+            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: select count(*) from (
+  select /*+mapjoin(subq2)*/ subq2.key as key, subq2.value as value1, b.value as value2 from
+  (
+    select * from
+    (
+      select a.key as key, a.value as value from tbl1 a where key < 8
+    ) subq1
+    where key < 6
+  ) subq2

[... 27 lines stripped ...]