HIVE-26722: HiveFilterSetOpTransposeRule incorrectly prunes UNION ALL…

ql/src/java/org/apache/hadoop/hive/ql/optimizer/calcite/rules/HiveFilterSetOpTransposeRule.java

@@ -42,8 +42,6 @@
 import org.apache.hadoop.hive.ql.optimizer.calcite.HiveCalciteUtil;
 import org.apache.hadoop.hive.ql.optimizer.calcite.HiveRelFactories;
 
-import com.google.common.collect.ImmutableList;
-
 public class HiveFilterSetOpTransposeRule extends FilterSetOpTransposeRule {
 
   public static final HiveFilterSetOpTransposeRule INSTANCE =
@@ -66,8 +64,8 @@ public class HiveFilterSetOpTransposeRule extends FilterSetOpTransposeRule {
    *       Op1 Op2
    *
    *
-   * It additionally can remove branch(es) of filter if its able to determine
-   * that they are going to generate empty result set.
+   * It additionally can remove branch(es) of filter if it's able to determine
+   * that they are going to generate an empty result set.
    */
   private HiveFilterSetOpTransposeRule(RelBuilderFactory relBuilderFactory) {
     super(relBuilderFactory);
@@ -111,18 +109,14 @@ public void onMatch(RelOptRuleCall call) {
         final RelMetadataQuery mq = call.getMetadataQuery();
         final RelOptPredicateList predicates = mq.getPulledUpPredicates(input);
         if (predicates != null) {
-          ImmutableList.Builder<RexNode> listBuilder = ImmutableList.builder();
-          listBuilder.addAll(predicates.pulledUpPredicates);
-          listBuilder.add(newCondition);
-          RexExecutor executor =
+          final RexExecutor executor =
               Util.first(filterRel.getCluster().getPlanner().getExecutor(), RexUtil.EXECUTOR);
-          final RexSimplify simplify = new RexSimplify(rexBuilder, RelOptPredicateList.EMPTY, executor);
-          final RexNode cond = RexUtil.composeConjunction(rexBuilder, listBuilder.build());
-          final RexNode x = simplify.simplifyUnknownAs(cond, RexUnknownAs.FALSE);
+          final RexSimplify simplify = new RexSimplify(rexBuilder, predicates, executor);
+          final RexNode x = simplify.simplifyUnknownAs(newCondition, RexUnknownAs.FALSE);
           if (x.isAlwaysFalse()) {
             // this is the last branch, and it is always false
             // We assume alwaysFalse filter will get pushed down to TS so this
-            // branch so it won't read any data.
+            // branch won't read any data.
             if (index == setOp.getInputs().size() - 1) {
               lastInput = relBuilder.push(input).filter(newCondition).build();
             }

ql/src/test/queries/clientpositive/union_all_filter_transpose.q

@@ -0,0 +1,32 @@
+# needed to avoid the simplification of CAST(NULL) into NULL
+set hive.cbo.rule.exclusion.regex=ReduceExpressionsRule\(Project\);
+
+CREATE EXTERNAL TABLE t (a string, b string);
+
+INSERT INTO t VALUES ('1000', 'b1');
+INSERT INTO t VALUES ('2000', 'b2');
+
+SELECT * FROM (
+  SELECT
+   a,
+   b
+  FROM t
+   UNION ALL
+  SELECT
+   a,
+   CAST(NULL AS string)
+   FROM t) AS t2
+WHERE a = 1000;
+
+EXPLAIN CBO
+SELECT * FROM (
+  SELECT
+   a,
+   b
+  FROM t
+   UNION ALL
+  SELECT
+   a,
+   CAST(NULL AS string)
+   FROM t) AS t2
+WHERE a = 1000;

ql/src/test/results/clientpositive/llap/create_view_when_mv_exists2.q.out

@@ -46,11 +46,10 @@ POSTHOOK: Input: default@t1
 POSTHOOK: Output: database:default
 POSTHOOK: Output: default@v1
 CBO PLAN:
-HiveProject(col0=[CAST(10):INTEGER])
-  HiveAggregate(group=[{0}])
-    HiveProject($f0=[true])
-      HiveFilter(condition=[=($0, 10)])
-        HiveTableScan(table=[[default, t1]], table:alias=[t1])
+HiveAggregate(group=[{0}])
+  HiveProject($f0=[CAST(10):INTEGER])
+    HiveFilter(condition=[=($0, 10)])
+      HiveTableScan(table=[[default, t1]], table:alias=[t1])
 
 PREHOOK: query: create view v1 as
 select sub.* from (select * from t1 where col0 > 2 union select * from t1 where col0 = 0) sub
@@ -80,11 +79,10 @@ POSTHOOK: Input: default@t1
 POSTHOOK: Input: default@v1
 #### A masked pattern was here ####
 CBO PLAN:
-HiveProject(col0=[CAST(10):INTEGER])
-  HiveAggregate(group=[{0}])
-    HiveProject($f0=[true])
-      HiveFilter(condition=[=($0, 10)])
-        HiveTableScan(table=[[default, t1]], table:alias=[t1])
+HiveAggregate(group=[{0}])
+  HiveProject($f0=[CAST(10):INTEGER])
+    HiveFilter(condition=[=($0, 10)])
+      HiveTableScan(table=[[default, t1]], table:alias=[t1])
 
 PREHOOK: query: select * from v1
 PREHOOK: type: QUERY

ql/src/test/results/clientpositive/llap/union_all_filter_transpose.q.out

@@ -0,0 +1,99 @@
+PREHOOK: query: CREATE EXTERNAL TABLE t (a string, b string)
+PREHOOK: type: CREATETABLE
+PREHOOK: Output: database:default
+PREHOOK: Output: default@t
+POSTHOOK: query: CREATE EXTERNAL TABLE t (a string, b string)
+POSTHOOK: type: CREATETABLE
+POSTHOOK: Output: database:default
+POSTHOOK: Output: default@t
+PREHOOK: query: INSERT INTO t VALUES ('1000', 'b1')
+PREHOOK: type: QUERY
+PREHOOK: Input: _dummy_database@_dummy_table
+PREHOOK: Output: default@t
+POSTHOOK: query: INSERT INTO t VALUES ('1000', 'b1')
+POSTHOOK: type: QUERY
+POSTHOOK: Input: _dummy_database@_dummy_table
+POSTHOOK: Output: default@t
+POSTHOOK: Lineage: t.a SCRIPT []
+POSTHOOK: Lineage: t.b SCRIPT []
+PREHOOK: query: INSERT INTO t VALUES ('2000', 'b2')
+PREHOOK: type: QUERY
+PREHOOK: Input: _dummy_database@_dummy_table
+PREHOOK: Output: default@t
+POSTHOOK: query: INSERT INTO t VALUES ('2000', 'b2')
+POSTHOOK: type: QUERY
+POSTHOOK: Input: _dummy_database@_dummy_table
+POSTHOOK: Output: default@t
+POSTHOOK: Lineage: t.a SCRIPT []
+POSTHOOK: Lineage: t.b SCRIPT []
+PREHOOK: query: SELECT * FROM (
+  SELECT
+   a,
+   b
+  FROM t
+   UNION ALL
+  SELECT
+   a,
+   CAST(NULL AS string)
+   FROM t) AS t2
+WHERE a = 1000
+PREHOOK: type: QUERY
+PREHOOK: Input: default@t
+#### A masked pattern was here ####
+POSTHOOK: query: SELECT * FROM (
+  SELECT
+   a,
+   b
+  FROM t
+   UNION ALL
+  SELECT
+   a,
+   CAST(NULL AS string)
+   FROM t) AS t2
+WHERE a = 1000
+POSTHOOK: type: QUERY
+POSTHOOK: Input: default@t
+#### A masked pattern was here ####
+1000	b1
+1000	NULL
+PREHOOK: query: EXPLAIN CBO
+SELECT * FROM (
+  SELECT
+   a,
+   b
+  FROM t
+   UNION ALL
+  SELECT
+   a,
+   CAST(NULL AS string)
+   FROM t) AS t2
+WHERE a = 1000
+PREHOOK: type: QUERY
+PREHOOK: Input: default@t
+#### A masked pattern was here ####
+POSTHOOK: query: EXPLAIN CBO
+SELECT * FROM (
+  SELECT
+   a,
+   b
+  FROM t
+   UNION ALL
+  SELECT
+   a,
+   CAST(NULL AS string)
+   FROM t) AS t2
+WHERE a = 1000
+POSTHOOK: type: QUERY
+POSTHOOK: Input: default@t
+#### A masked pattern was here ####
+Excluded rules: ReduceExpressionsRule\(Project\)
+
+CBO PLAN:
+HiveUnion(all=[true])
+  HiveProject(a=[$0], b=[$1])
+    HiveFilter(condition=[=(CAST($0):DOUBLE, 1000)])
+      HiveTableScan(table=[[default, t]], table:alias=[t])
+  HiveProject(a=[$0], _o__c1=[null:VARCHAR(2147483647) CHARACTER SET "UTF-16LE"])
+    HiveFilter(condition=[=(CAST($0):DOUBLE, 1000)])
+      HiveTableScan(table=[[default, t]], table:alias=[t])
+