HIVE-29447: Incorrect nullability inference when transforming SEARCH expression back to disjunctions

[kasakrisz]

What changes were proposed in this pull request?

Why are the changes needed?

Does this PR introduce any user-facing change?

How was this patch tested?

mvn test -Dtest.output.overwrite -Dtest=TestMiniLlapLocalCliDriver -Dqfile=cbo_search.q -pl itests/qtest -Pitests

[sonarqubecloud]

Quality Gate passed

Issues
0 New issues
0 Accepted issues

Measures
0 Security Hotspots
0.0% Coverage on New Code
0.0% Duplication on New Code

See analysis details on SonarQube Cloud

[soumyakanti3578]

@kasakrisz
From the failed tests, it looks like CAST would not pass the Filter litmus test, as seen in the test failure: materialized_view_rewrite_in_between.q.

How about just creating a new RexCall with the type of the search, since we want the new expression to have the same type as the SEARCH? I tried a few failing tests with this change and they all passed.

--- a/ql/src/java/org/apache/hadoop/hive/ql/optimizer/calcite/SearchTransformer.java
+++ b/ql/src/java/org/apache/hadoop/hive/ql/optimizer/calcite/SearchTransformer.java
@@ -59,22 +59,24 @@ public class SearchTransformer<C extends Comparable<C>> {
   private final RexNode ref;
   private final Sarg<C> sarg;
   private final RexUnknownAs unknownContext;
-  protected final RelDataType type;
+  protected final RelDataType operandType;
+  private final RelDataType expressionType;

   public SearchTransformer(RexBuilder rexBuilder, RexCall search, final RexUnknownAs unknownContext) {
     this.rexBuilder = rexBuilder;
     ref = search.getOperands().get(0);
     RexLiteral literal = (RexLiteral) search.operands.get(1);
     sarg = Objects.requireNonNull(literal.getValueAs(Sarg.class), "Sarg");
-    type = literal.getType();
+    operandType = literal.getType();
     this.unknownContext = unknownContext;
+    this.expressionType = search.getType();
   }

   public RexNode transform() {
     PerfLogger perfLogger = SessionState.getPerfLogger();
     perfLogger.perfLogBegin(this.getClass().getName(), PerfLogger.SEARCH_TRANSFORMER);

-    RangeConverter<C> consumer = new RangeConverter<>(rexBuilder, type, ref);
+    RangeConverter<C> consumer = new RangeConverter<>(rexBuilder, operandType, ref);
     RangeSets.forEach(sarg.rangeSet, consumer);

     List<RexNode> orList = new ArrayList<>();
@@ -101,6 +103,11 @@ public RexNode transform() {
       x = RexUtil.composeConjunction(rexBuilder, Arrays.asList(notNull, x));
     }
     perfLogger.perfLogEnd(this.getClass().getName(), PerfLogger.SEARCH_TRANSFORMER);
+
+    if (!expressionType.equals(x.getType())) {
+      x = rexBuilder.makeCall(expressionType, ((RexCall) x).getOperator(), ((RexCall) x).getOperands());
+    }
+
     return x;
   }