remove duplicated regex match operator alias

Signed-off-by: Jialiang Liang <jiallian@amazon.com>

Author: RyanL1997

core/src/main/java/org/opensearch/sql/calcite/CalciteRelNodeVisitor.java

@@ -181,9 +181,7 @@ public RelNode visitRegex(Regex node, CalcitePlanContext context) {
 
     RexNode regexCondition =
         context.rexBuilder.makeCall(
-            org.opensearch.sql.expression.function.PPLBuiltinOperators.REGEX_MATCH,
-            fieldRex,
-            patternRex);
+            org.apache.calcite.sql.fun.SqlLibraryOperators.REGEXP_CONTAINS, fieldRex, patternRex);
 
     if (node.isNegated()) {
       regexCondition = context.rexBuilder.makeCall(SqlStdOperatorTable.NOT, regexCondition);

core/src/main/java/org/opensearch/sql/expression/function/PPLBuiltinOperators.java

@@ -22,7 +22,6 @@
 import org.apache.calcite.linq4j.tree.Expression;
 import org.apache.calcite.rex.RexCall;
 import org.apache.calcite.sql.SqlOperator;
-import org.apache.calcite.sql.fun.SqlLibraryOperators;
 import org.apache.calcite.sql.type.ReturnTypes;
 import org.apache.calcite.sql.type.SqlTypeTransforms;
 import org.apache.calcite.sql.util.ReflectiveSqlOperatorTable;
@@ -381,7 +380,6 @@ public class PPLBuiltinOperators extends ReflectiveSqlOperatorTable {
       RELEVANCE_QUERY_FUNCTION_INSTANCE.toUDF("multi_match", false);
   public static final SqlOperator NUMBER_TO_STRING =
       new NumberToStringFunction().toUDF("NUMBER_TO_STRING");
-  public static final SqlOperator REGEX_MATCH = SqlLibraryOperators.REGEXP_CONTAINS;
 
   /**
    * Returns the PPL specific operator table, creating it if necessary.

core/src/main/java/org/opensearch/sql/expression/function/PPLFuncImpTable.java

@@ -160,7 +160,6 @@
 import static org.opensearch.sql.expression.function.BuiltinFunctionName.RAND;
 import static org.opensearch.sql.expression.function.BuiltinFunctionName.REDUCE;
 import static org.opensearch.sql.expression.function.BuiltinFunctionName.REGEXP;
-import static org.opensearch.sql.expression.function.BuiltinFunctionName.REGEX_MATCH;
 import static org.opensearch.sql.expression.function.BuiltinFunctionName.REPLACE;
 import static org.opensearch.sql.expression.function.BuiltinFunctionName.REVERSE;
 import static org.opensearch.sql.expression.function.BuiltinFunctionName.RIGHT;
@@ -712,7 +711,6 @@ void populate() {
       registerOperator(SIMPLE_QUERY_STRING, PPLBuiltinOperators.SIMPLE_QUERY_STRING);
       registerOperator(QUERY_STRING, PPLBuiltinOperators.QUERY_STRING);
       registerOperator(MULTI_MATCH, PPLBuiltinOperators.MULTI_MATCH);
-      registerOperator(REGEX_MATCH, PPLBuiltinOperators.REGEX_MATCH);
 
       // Register PPL Datetime UDF operator
       registerOperator(TIMESTAMP, PPLBuiltinOperators.TIMESTAMP);