diff --git a/core/src/main/java/org/apache/calcite/adapter/enumerable/RexImpTable.java b/core/src/main/java/org/apache/calcite/adapter/enumerable/RexImpTable.java
index 1cac3913ea84..7f358521573b 100644
--- a/core/src/main/java/org/apache/calcite/adapter/enumerable/RexImpTable.java
+++ b/core/src/main/java/org/apache/calcite/adapter/enumerable/RexImpTable.java
@@ -2332,6 +2332,8 @@ private static class BinaryImplementor extends AbstractRexCallImplementor {
         final Primitive primitive = Primitive.ofBoxOr(type0);
         if (primitive == null
             || type1 == BigDecimal.class
+            || backupMethodName.equals("plus")
+            && isNumberOrString(type0) && isNumberOrString(type1)
             || COMPARISON_OPERATORS.contains(op)
             && !COMP_OP_TYPES.contains(primitive)) {
           return Expressions.call(SqlFunctions.class, backupMethodName,
@@ -2352,6 +2354,15 @@ private static class BinaryImplementor extends AbstractRexCallImplementor {
           argValueList.get(0), argValueList.get(1));
     }
 
+    // see https://olapio.atlassian.net/browse/KE-42243
+    private boolean isNumberOrString(Type type) {
+      if (type == String.class || type == BigDecimal.class) {
+        return true;
+      }
+      Primitive primitive = Primitive.ofBoxOr(type);
+      return primitive != null && Number.class.isAssignableFrom(primitive.boxClass);
+    }
+
     /** Returns whether any of a call's operands have ANY type. */
     private static boolean anyAnyOperands(RexCall call) {
       for (RexNode operand : call.operands) {
diff --git a/core/src/main/java/org/apache/calcite/runtime/SqlFunctions.java b/core/src/main/java/org/apache/calcite/runtime/SqlFunctions.java
index c23aa06e04f4..cc0e54a73564 100644
--- a/core/src/main/java/org/apache/calcite/runtime/SqlFunctions.java
+++ b/core/src/main/java/org/apache/calcite/runtime/SqlFunctions.java
@@ -1006,30 +1006,35 @@ public static int plus(int b0, int b1) {
   }
 
   // see https://olapio.atlassian.net/browse/KE-42084
-  public static Double plus(String s0, String s1) {
+  // see https://olapio.atlassian.net/browse/KE-42243
+  public static BigDecimal plus(String s0, String s1) {
     try {
-      return plus(toBigDecimal(s0), toBigDecimal(s1)).doubleValue();
+      return plus(toBigDecimal(s0), toBigDecimal(s1));
     } catch (NumberFormatException ignored) {
       return null;
     }
   }
 
-  public static Double plus(String s0, BigDecimal b1) {
+  public static BigDecimal plus(String s0, BigDecimal b1) {
     try {
-      return plus(toBigDecimal(s0), b1).doubleValue();
+      return plus(toBigDecimal(s0), b1);
     } catch (NumberFormatException ignored) {
       return null;
     }
   }
 
-  public static Double plus(String s0, Number b1) {
+  public static BigDecimal plus(String s0, Number b1) {
     return plus(s0, toBigDecimal(b1));
   }
 
-  public static Double plus(Number b1, String s0) {
+  public static BigDecimal plus(Number b1, String s0) {
     return plus(s0, toBigDecimal(b1));
   }
 
+  public static BigDecimal plus(Number b1, Number b2) {
+    return plus(toBigDecimal(b1), toBigDecimal(b2));
+  }
+
   /** SQL <code>+</code> operator applied to Object values (at least one operand
    * has ANY type; either may be null). */
   public static @PolyNull Object plusAny(@PolyNull Object b0,
@@ -2213,7 +2218,8 @@ public static BigDecimal toBigDecimal(String s) {
   public static BigDecimal toBigDecimal(Number number) {
     // There are some values of "long" that cannot be represented as "double".
     // Not so "int". If it isn't a long, go straight to double.
-    return number instanceof BigDecimal ? (BigDecimal) number
+    return number == null ? null
+        : number instanceof BigDecimal ? (BigDecimal) number
         : number instanceof BigInteger ? new BigDecimal((BigInteger) number)
         : number instanceof Long ? new BigDecimal(number.longValue())
         : new BigDecimal(number.doubleValue());
diff --git a/core/src/main/java/org/apache/calcite/sql/validate/implicit/TypeCoercionImpl.java b/core/src/main/java/org/apache/calcite/sql/validate/implicit/TypeCoercionImpl.java
index ce562a9a5167..2a108524e3bf 100644
--- a/core/src/main/java/org/apache/calcite/sql/validate/implicit/TypeCoercionImpl.java
+++ b/core/src/main/java/org/apache/calcite/sql/validate/implicit/TypeCoercionImpl.java
@@ -173,6 +173,12 @@ protected boolean binaryArithmeticWithStrings(
       SqlCallBinding binding,
       RelDataType left,
       RelDataType right) {
+    // see https://olapio.atlassian.net/browse/KE-42243
+    // Calcite's implicit conversion may fail when the operator is "plus" and the left and right
+    // sides are numeric and string types respectively, which will not be supported in Kylin,
+    // and the logic is commented out for now.
+    return false;
+
     // For expression "NUMERIC <OP> CHARACTER",
     // PostgreSQL and MS-SQL coerce the CHARACTER operand to NUMERIC,
     // i.e. for '9':VARCHAR(1) / 2: INT, '9' would be coerced to INTEGER,
@@ -183,20 +189,20 @@ protected boolean binaryArithmeticWithStrings(
 
     // Keep sync with PostgreSQL and MS-SQL because their behaviors are more in
     // line with the SQL standard.
-    if (SqlTypeUtil.isString(left) && SqlTypeUtil.isNumeric(right)) {
-      // If the numeric operand is DECIMAL type, coerce the STRING operand to
-      // max precision/scale DECIMAL.
-      if (SqlTypeUtil.isDecimal(right)) {
-        right = SqlTypeUtil.getMaxPrecisionScaleDecimal(factory);
-      }
-      return coerceOperandType(binding.getScope(), binding.getCall(), 0, right);
-    } else if (SqlTypeUtil.isNumeric(left) && SqlTypeUtil.isString(right)) {
-      if (SqlTypeUtil.isDecimal(left)) {
-        left = SqlTypeUtil.getMaxPrecisionScaleDecimal(factory);
-      }
-      return coerceOperandType(binding.getScope(), binding.getCall(), 1, left);
-    }
-    return false;
+//    if (SqlTypeUtil.isString(left) && SqlTypeUtil.isNumeric(right)) {
+//      // If the numeric operand is DECIMAL type, coerce the STRING operand to
+//      // max precision/scale DECIMAL.
+//      if (SqlTypeUtil.isDecimal(right)) {
+//        right = SqlTypeUtil.getMaxPrecisionScaleDecimal(factory);
+//      }
+//      return coerceOperandType(binding.getScope(), binding.getCall(), 0, right);
+//    } else if (SqlTypeUtil.isNumeric(left) && SqlTypeUtil.isString(right)) {
+//      if (SqlTypeUtil.isDecimal(left)) {
+//        left = SqlTypeUtil.getMaxPrecisionScaleDecimal(factory);
+//      }
+//      return coerceOperandType(binding.getScope(), binding.getCall(), 1, left);
+//    }
+//    return false;
   }
 
   /**