diff --git a/flink-table/flink-table-planner/src/main/java/org/apache/flink/table/planner/expressions/converter/converters/ArrayConverter.java b/flink-table/flink-table-planner/src/main/java/org/apache/flink/table/planner/expressions/converter/converters/ArrayConverter.java
index 7d76169..8e2f8ad 100644
--- a/flink-table/flink-table-planner/src/main/java/org/apache/flink/table/planner/expressions/converter/converters/ArrayConverter.java
+++ b/flink-table/flink-table-planner/src/main/java/org/apache/flink/table/planner/expressions/converter/converters/ArrayConverter.java
@@ -18,6 +18,7 @@
 
 package org.apache.flink.table.planner.expressions.converter.converters;
 
+import org.apache.flink.annotation.Internal;
 import org.apache.flink.table.expressions.CallExpression;
 import org.apache.flink.table.functions.BuiltInFunctionDefinitions;
 import org.apache.flink.table.planner.expressions.converter.CallExpressionConvertRule;
@@ -31,6 +32,7 @@
 import static org.apache.flink.table.planner.expressions.converter.ExpressionConverter.toRexNodes;
 
 /** Conversion for {@link BuiltInFunctionDefinitions#ARRAY}. */
+@Internal
 class ArrayConverter extends CustomizedConverter {
     @Override
     public RexNode convert(CallExpression call, CallExpressionConvertRule.ConvertContext context) {
diff --git a/flink-table/flink-table-planner/src/main/java/org/apache/flink/table/planner/expressions/converter/converters/AsConverter.java b/flink-table/flink-table-planner/src/main/java/org/apache/flink/table/planner/expressions/converter/converters/AsConverter.java
index dd304d6..37d046e 100644
--- a/flink-table/flink-table-planner/src/main/java/org/apache/flink/table/planner/expressions/converter/converters/AsConverter.java
+++ b/flink-table/flink-table-planner/src/main/java/org/apache/flink/table/planner/expressions/converter/converters/AsConverter.java
@@ -18,6 +18,7 @@
 
 package org.apache.flink.table.planner.expressions.converter.converters;
 
+import org.apache.flink.annotation.Internal;
 import org.apache.flink.table.expressions.CallExpression;
 import org.apache.flink.table.expressions.ValueLiteralExpression;
 import org.apache.flink.table.functions.BuiltInFunctionDefinitions;
@@ -28,6 +29,7 @@
 import static org.apache.flink.table.planner.expressions.converter.ExpressionConverter.extractValue;
 
 /** Conversion for {@link BuiltInFunctionDefinitions#AS}. */
+@Internal
 class AsConverter extends CustomizedConverter {
     @Override
     public RexNode convert(CallExpression call, CallExpressionConvertRule.ConvertContext context) {
diff --git a/flink-table/flink-table-planner/src/main/java/org/apache/flink/table/planner/expressions/converter/converters/BetweenConverter.java b/flink-table/flink-table-planner/src/main/java/org/apache/flink/table/planner/expressions/converter/converters/BetweenConverter.java
index a8b2822..cb0ed68 100644
--- a/flink-table/flink-table-planner/src/main/java/org/apache/flink/table/planner/expressions/converter/converters/BetweenConverter.java
+++ b/flink-table/flink-table-planner/src/main/java/org/apache/flink/table/planner/expressions/converter/converters/BetweenConverter.java
@@ -18,6 +18,7 @@
 
 package org.apache.flink.table.planner.expressions.converter.converters;
 
+import org.apache.flink.annotation.Internal;
 import org.apache.flink.table.expressions.CallExpression;
 import org.apache.flink.table.functions.BuiltInFunctionDefinitions;
 import org.apache.flink.table.planner.expressions.converter.CallExpressionConvertRule;
@@ -30,6 +31,7 @@
 import static org.apache.flink.table.planner.expressions.converter.ExpressionConverter.toRexNodes;
 
 /** Conversion for {@link BuiltInFunctionDefinitions#BETWEEN}. */
+@Internal
 class BetweenConverter extends CustomizedConverter {
     @Override
     public RexNode convert(CallExpression call, CallExpressionConvertRule.ConvertContext context) {
diff --git a/flink-table/flink-table-planner/src/main/java/org/apache/flink/table/planner/expressions/converter/converters/CastConverter.java b/flink-table/flink-table-planner/src/main/java/org/apache/flink/table/planner/expressions/converter/converters/CastConverter.java
index cec1de3..e091fa1 100644
--- a/flink-table/flink-table-planner/src/main/java/org/apache/flink/table/planner/expressions/converter/converters/CastConverter.java
+++ b/flink-table/flink-table-planner/src/main/java/org/apache/flink/table/planner/expressions/converter/converters/CastConverter.java
@@ -18,6 +18,7 @@
 
 package org.apache.flink.table.planner.expressions.converter.converters;
 
+import org.apache.flink.annotation.Internal;
 import org.apache.flink.table.expressions.CallExpression;
 import org.apache.flink.table.expressions.TypeLiteralExpression;
 import org.apache.flink.table.functions.BuiltInFunctionDefinitions;
@@ -27,6 +28,7 @@
 import org.apache.calcite.rex.RexNode;
 
 /** Conversion for {@link BuiltInFunctionDefinitions#CAST}. */
+@Internal
 class CastConverter extends CustomizedConverter {
     @Override
     public RexNode convert(CallExpression call, CallExpressionConvertRule.ConvertContext context) {
diff --git a/flink-table/flink-table-planner/src/main/java/org/apache/flink/table/planner/expressions/converter/converters/GetConverter.java b/flink-table/flink-table-planner/src/main/java/org/apache/flink/table/planner/expressions/converter/converters/GetConverter.java
index c62866c..6e46518 100644
--- a/flink-table/flink-table-planner/src/main/java/org/apache/flink/table/planner/expressions/converter/converters/GetConverter.java
+++ b/flink-table/flink-table-planner/src/main/java/org/apache/flink/table/planner/expressions/converter/converters/GetConverter.java
@@ -18,6 +18,7 @@
 
 package org.apache.flink.table.planner.expressions.converter.converters;
 
+import org.apache.flink.annotation.Internal;
 import org.apache.flink.table.expressions.CallExpression;
 import org.apache.flink.table.expressions.ExpressionUtils;
 import org.apache.flink.table.expressions.ValueLiteralExpression;
@@ -31,6 +32,7 @@
 import static org.apache.flink.table.planner.expressions.converter.ExpressionConverter.extractValue;
 
 /** Conversion for {@link BuiltInFunctionDefinitions#GET}. */
+@Internal
 class GetConverter extends CustomizedConverter {
     @Override
     public RexNode convert(CallExpression call, CallExpressionConvertRule.ConvertContext context) {
diff --git a/flink-table/flink-table-planner/src/main/java/org/apache/flink/table/planner/expressions/converter/converters/InConverter.java b/flink-table/flink-table-planner/src/main/java/org/apache/flink/table/planner/expressions/converter/converters/InConverter.java
index 80005af..e06379a 100644
--- a/flink-table/flink-table-planner/src/main/java/org/apache/flink/table/planner/expressions/converter/converters/InConverter.java
+++ b/flink-table/flink-table-planner/src/main/java/org/apache/flink/table/planner/expressions/converter/converters/InConverter.java
@@ -18,6 +18,7 @@
 
 package org.apache.flink.table.planner.expressions.converter.converters;
 
+import org.apache.flink.annotation.Internal;
 import org.apache.flink.table.expressions.CallExpression;
 import org.apache.flink.table.expressions.Expression;
 import org.apache.flink.table.expressions.TableReferenceExpression;
@@ -35,6 +36,7 @@
 import static org.apache.flink.table.planner.expressions.converter.ExpressionConverter.toRexNodes;
 
 /** Conversion for {@link BuiltInFunctionDefinitions#IN}. */
+@Internal
 class InConverter extends CustomizedConverter {
     @Override
     public RexNode convert(CallExpression call, CallExpressionConvertRule.ConvertContext context) {
diff --git a/flink-table/flink-table-planner/src/main/java/org/apache/flink/table/planner/expressions/converter/converters/IsJsonConverter.java b/flink-table/flink-table-planner/src/main/java/org/apache/flink/table/planner/expressions/converter/converters/IsJsonConverter.java
index 49eded8..43d95d4 100644
--- a/flink-table/flink-table-planner/src/main/java/org/apache/flink/table/planner/expressions/converter/converters/IsJsonConverter.java
+++ b/flink-table/flink-table-planner/src/main/java/org/apache/flink/table/planner/expressions/converter/converters/IsJsonConverter.java
@@ -18,6 +18,7 @@
 
 package org.apache.flink.table.planner.expressions.converter.converters;
 
+import org.apache.flink.annotation.Internal;
 import org.apache.flink.table.api.JsonType;
 import org.apache.flink.table.api.TableException;
 import org.apache.flink.table.expressions.CallExpression;
@@ -30,6 +31,7 @@
 import org.apache.calcite.sql.SqlOperator;
 
 /** Conversion for {@link BuiltInFunctionDefinitions#IS_JSON}. */
+@Internal
 class IsJsonConverter extends CustomizedConverter {
 
     @Override
diff --git a/flink-table/flink-table-planner/src/main/java/org/apache/flink/table/planner/expressions/converter/converters/JsonExistsConverter.java b/flink-table/flink-table-planner/src/main/java/org/apache/flink/table/planner/expressions/converter/converters/JsonExistsConverter.java
index 27901b7..5df9efd 100644
--- a/flink-table/flink-table-planner/src/main/java/org/apache/flink/table/planner/expressions/converter/converters/JsonExistsConverter.java
+++ b/flink-table/flink-table-planner/src/main/java/org/apache/flink/table/planner/expressions/converter/converters/JsonExistsConverter.java
@@ -18,6 +18,7 @@
 
 package org.apache.flink.table.planner.expressions.converter.converters;
 
+import org.apache.flink.annotation.Internal;
 import org.apache.flink.table.api.JsonExistsOnError;
 import org.apache.flink.table.api.TableException;
 import org.apache.flink.table.expressions.CallExpression;
@@ -33,6 +34,7 @@
 import java.util.List;
 
 /** Conversion for {@link BuiltInFunctionDefinitions#JSON_EXISTS}. */
+@Internal
 class JsonExistsConverter extends CustomizedConverter {
     @Override
     public RexNode convert(CallExpression call, CallExpressionConvertRule.ConvertContext context) {
diff --git a/flink-table/flink-table-planner/src/main/java/org/apache/flink/table/planner/expressions/converter/converters/JsonQueryConverter.java b/flink-table/flink-table-planner/src/main/java/org/apache/flink/table/planner/expressions/converter/converters/JsonQueryConverter.java
index 1c4480c..bcbf365 100644
--- a/flink-table/flink-table-planner/src/main/java/org/apache/flink/table/planner/expressions/converter/converters/JsonQueryConverter.java
+++ b/flink-table/flink-table-planner/src/main/java/org/apache/flink/table/planner/expressions/converter/converters/JsonQueryConverter.java
@@ -18,6 +18,7 @@
 
 package org.apache.flink.table.planner.expressions.converter.converters;
 
+import org.apache.flink.annotation.Internal;
 import org.apache.flink.table.api.JsonQueryOnEmptyOrError;
 import org.apache.flink.table.api.JsonQueryWrapper;
 import org.apache.flink.table.api.TableException;
@@ -35,6 +36,7 @@
 import java.util.List;
 
 /** Conversion for {@link BuiltInFunctionDefinitions#JSON_QUERY}. */
+@Internal
 class JsonQueryConverter extends CustomizedConverter {
     @Override
     public RexNode convert(CallExpression call, CallExpressionConvertRule.ConvertContext context) {
diff --git a/flink-table/flink-table-planner/src/main/java/org/apache/flink/table/planner/expressions/converter/converters/JsonValueConverter.java b/flink-table/flink-table-planner/src/main/java/org/apache/flink/table/planner/expressions/converter/converters/JsonValueConverter.java
index 7336c4e..c08570a 100644
--- a/flink-table/flink-table-planner/src/main/java/org/apache/flink/table/planner/expressions/converter/converters/JsonValueConverter.java
+++ b/flink-table/flink-table-planner/src/main/java/org/apache/flink/table/planner/expressions/converter/converters/JsonValueConverter.java
@@ -18,6 +18,7 @@
 
 package org.apache.flink.table.planner.expressions.converter.converters;
 
+import org.apache.flink.annotation.Internal;
 import org.apache.flink.table.api.JsonValueOnEmptyOrError;
 import org.apache.flink.table.api.TableException;
 import org.apache.flink.table.expressions.CallExpression;
@@ -40,6 +41,7 @@
 import static org.apache.flink.table.planner.utils.ShortcutUtils.unwrapTypeFactory;
 
 /** Conversion for {@link BuiltInFunctionDefinitions#JSON_VALUE}. */
+@Internal
 class JsonValueConverter extends CustomizedConverter {
 
     @Override
diff --git a/flink-table/flink-table-planner/src/main/java/org/apache/flink/table/planner/expressions/converter/converters/MapConverter.java b/flink-table/flink-table-planner/src/main/java/org/apache/flink/table/planner/expressions/converter/converters/MapConverter.java
index 7b9d488..f87dfc1 100644
--- a/flink-table/flink-table-planner/src/main/java/org/apache/flink/table/planner/expressions/converter/converters/MapConverter.java
+++ b/flink-table/flink-table-planner/src/main/java/org/apache/flink/table/planner/expressions/converter/converters/MapConverter.java
@@ -18,6 +18,7 @@
 
 package org.apache.flink.table.planner.expressions.converter.converters;
 
+import org.apache.flink.annotation.Internal;
 import org.apache.flink.table.expressions.CallExpression;
 import org.apache.flink.table.expressions.Expression;
 import org.apache.flink.table.functions.BuiltInFunctionDefinitions;
@@ -32,6 +33,7 @@
 import static org.apache.flink.table.planner.expressions.converter.ExpressionConverter.toRexNodes;
 
 /** Conversion for {@link BuiltInFunctionDefinitions#MAP}. */
+@Internal
 class MapConverter extends CustomizedConverter {
     @Override
     public RexNode convert(CallExpression call, CallExpressionConvertRule.ConvertContext context) {
diff --git a/flink-table/flink-table-planner/src/main/java/org/apache/flink/table/planner/expressions/converter/converters/NotBetweenConverter.java b/flink-table/flink-table-planner/src/main/java/org/apache/flink/table/planner/expressions/converter/converters/NotBetweenConverter.java
index cc2cc12..dd53f12 100644
--- a/flink-table/flink-table-planner/src/main/java/org/apache/flink/table/planner/expressions/converter/converters/NotBetweenConverter.java
+++ b/flink-table/flink-table-planner/src/main/java/org/apache/flink/table/planner/expressions/converter/converters/NotBetweenConverter.java
@@ -18,6 +18,7 @@
 
 package org.apache.flink.table.planner.expressions.converter.converters;
 
+import org.apache.flink.annotation.Internal;
 import org.apache.flink.table.expressions.CallExpression;
 import org.apache.flink.table.functions.BuiltInFunctionDefinitions;
 import org.apache.flink.table.planner.expressions.converter.CallExpressionConvertRule;
@@ -30,6 +31,7 @@
 import static org.apache.flink.table.planner.expressions.converter.ExpressionConverter.toRexNodes;
 
 /** Conversion for {@link BuiltInFunctionDefinitions#NOT_BETWEEN}. */
+@Internal
 class NotBetweenConverter extends CustomizedConverter {
     @Override
     public RexNode convert(CallExpression call, CallExpressionConvertRule.ConvertContext context) {
diff --git a/flink-table/flink-table-planner/src/main/java/org/apache/flink/table/planner/expressions/converter/converters/OrderAscConverter.java b/flink-table/flink-table-planner/src/main/java/org/apache/flink/table/planner/expressions/converter/converters/OrderAscConverter.java
index 508d40a..8e5e544 100644
--- a/flink-table/flink-table-planner/src/main/java/org/apache/flink/table/planner/expressions/converter/converters/OrderAscConverter.java
+++ b/flink-table/flink-table-planner/src/main/java/org/apache/flink/table/planner/expressions/converter/converters/OrderAscConverter.java
@@ -18,6 +18,7 @@
 
 package org.apache.flink.table.planner.expressions.converter.converters;
 
+import org.apache.flink.annotation.Internal;
 import org.apache.flink.table.expressions.CallExpression;
 import org.apache.flink.table.functions.BuiltInFunctionDefinitions;
 import org.apache.flink.table.planner.expressions.converter.CallExpressionConvertRule;
@@ -25,6 +26,7 @@
 import org.apache.calcite.rex.RexNode;
 
 /** Conversion for {@link BuiltInFunctionDefinitions#ORDER_ASC}. */
+@Internal
 class OrderAscConverter extends CustomizedConverter {
     @Override
     public RexNode convert(CallExpression call, CallExpressionConvertRule.ConvertContext context) {
diff --git a/flink-table/flink-table-planner/src/main/java/org/apache/flink/table/planner/expressions/converter/converters/PlusConverter.java b/flink-table/flink-table-planner/src/main/java/org/apache/flink/table/planner/expressions/converter/converters/PlusConverter.java
index c804d0e..47dfbd0 100644
--- a/flink-table/flink-table-planner/src/main/java/org/apache/flink/table/planner/expressions/converter/converters/PlusConverter.java
+++ b/flink-table/flink-table-planner/src/main/java/org/apache/flink/table/planner/expressions/converter/converters/PlusConverter.java
@@ -18,6 +18,7 @@
 
 package org.apache.flink.table.planner.expressions.converter.converters;
 
+import org.apache.flink.annotation.Internal;
 import org.apache.flink.table.expressions.CallExpression;
 import org.apache.flink.table.functions.BuiltInFunctionDefinitions;
 import org.apache.flink.table.planner.expressions.converter.CallExpressionConvertRule;
@@ -35,6 +36,7 @@
 import static org.apache.flink.table.runtime.typeutils.TypeCheckUtils.isTimeInterval;
 
 /** Conversion for {@link BuiltInFunctionDefinitions#PLUS}. */
+@Internal
 class PlusConverter extends CustomizedConverter {
     @Override
     public RexNode convert(CallExpression call, CallExpressionConvertRule.ConvertContext context) {
diff --git a/flink-table/flink-table-planner/src/main/java/org/apache/flink/table/planner/expressions/converter/converters/ReinterpretCastConverter.java b/flink-table/flink-table-planner/src/main/java/org/apache/flink/table/planner/expressions/converter/converters/ReinterpretCastConverter.java
index 02219d4..e7a0ff6 100644
--- a/flink-table/flink-table-planner/src/main/java/org/apache/flink/table/planner/expressions/converter/converters/ReinterpretCastConverter.java
+++ b/flink-table/flink-table-planner/src/main/java/org/apache/flink/table/planner/expressions/converter/converters/ReinterpretCastConverter.java
@@ -18,6 +18,7 @@
 
 package org.apache.flink.table.planner.expressions.converter.converters;
 
+import org.apache.flink.annotation.Internal;
 import org.apache.flink.table.expressions.CallExpression;
 import org.apache.flink.table.expressions.TypeLiteralExpression;
 import org.apache.flink.table.functions.BuiltInFunctionDefinitions;
@@ -26,6 +27,7 @@
 import org.apache.calcite.rex.RexNode;
 
 /** Conversion for {@link BuiltInFunctionDefinitions#REINTERPRET_CAST}. */
+@Internal
 class ReinterpretCastConverter extends CustomizedConverter {
     @Override
     public RexNode convert(CallExpression call, CallExpressionConvertRule.ConvertContext context) {
diff --git a/flink-table/flink-table-planner/src/main/java/org/apache/flink/table/planner/expressions/converter/converters/ReplaceConverter.java b/flink-table/flink-table-planner/src/main/java/org/apache/flink/table/planner/expressions/converter/converters/ReplaceConverter.java
index b8eaddf..97ee1da 100644
--- a/flink-table/flink-table-planner/src/main/java/org/apache/flink/table/planner/expressions/converter/converters/ReplaceConverter.java
+++ b/flink-table/flink-table-planner/src/main/java/org/apache/flink/table/planner/expressions/converter/converters/ReplaceConverter.java
@@ -18,6 +18,7 @@
 
 package org.apache.flink.table.planner.expressions.converter.converters;
 
+import org.apache.flink.annotation.Internal;
 import org.apache.flink.table.expressions.CallExpression;
 import org.apache.flink.table.expressions.Expression;
 import org.apache.flink.table.functions.BuiltInFunctionDefinitions;
@@ -31,6 +32,7 @@
 import static org.apache.flink.table.planner.expressions.converter.ExpressionConverter.toRexNodes;
 
 /** Conversion for {@link BuiltInFunctionDefinitions#REPLACE}. */
+@Internal
 class ReplaceConverter extends CustomizedConverter {
     @Override
     public RexNode convert(CallExpression call, CallExpressionConvertRule.ConvertContext context) {
diff --git a/flink-table/flink-table-planner/src/main/java/org/apache/flink/table/planner/expressions/converter/converters/RowConverter.java b/flink-table/flink-table-planner/src/main/java/org/apache/flink/table/planner/expressions/converter/converters/RowConverter.java
index 1c51dd9..2996e3a 100644
--- a/flink-table/flink-table-planner/src/main/java/org/apache/flink/table/planner/expressions/converter/converters/RowConverter.java
+++ b/flink-table/flink-table-planner/src/main/java/org/apache/flink/table/planner/expressions/converter/converters/RowConverter.java
@@ -18,6 +18,7 @@
 
 package org.apache.flink.table.planner.expressions.converter.converters;
 
+import org.apache.flink.annotation.Internal;
 import org.apache.flink.table.expressions.CallExpression;
 import org.apache.flink.table.functions.BuiltInFunctionDefinitions;
 import org.apache.flink.table.planner.expressions.converter.CallExpressionConvertRule;
@@ -31,6 +32,7 @@
 import static org.apache.flink.table.planner.expressions.converter.ExpressionConverter.toRexNodes;
 
 /** Conversion for {@link BuiltInFunctionDefinitions#ROW}. */
+@Internal
 class RowConverter extends CustomizedConverter {
     @Override
     public RexNode convert(CallExpression call, CallExpressionConvertRule.ConvertContext context) {
diff --git a/flink-table/flink-table-planner/src/main/java/org/apache/flink/table/planner/expressions/converter/converters/SqrtConverter.java b/flink-table/flink-table-planner/src/main/java/org/apache/flink/table/planner/expressions/converter/converters/SqrtConverter.java
index 03b1a6d..191bf10 100644
--- a/flink-table/flink-table-planner/src/main/java/org/apache/flink/table/planner/expressions/converter/converters/SqrtConverter.java
+++ b/flink-table/flink-table-planner/src/main/java/org/apache/flink/table/planner/expressions/converter/converters/SqrtConverter.java
@@ -18,6 +18,7 @@
 
 package org.apache.flink.table.planner.expressions.converter.converters;
 
+import org.apache.flink.annotation.Internal;
 import org.apache.flink.table.expressions.ApiExpressionUtils;
 import org.apache.flink.table.expressions.CallExpression;
 import org.apache.flink.table.functions.BuiltInFunctionDefinitions;
@@ -31,6 +32,7 @@
 import static org.apache.flink.table.planner.expressions.converter.ExpressionConverter.toRexNodes;
 
 /** Conversion for {@link BuiltInFunctionDefinitions#SQRT}. */
+@Internal
 class SqrtConverter extends CustomizedConverter {
     @Override
     public RexNode convert(CallExpression call, CallExpressionConvertRule.ConvertContext context) {
diff --git a/flink-table/flink-table-planner/src/main/java/org/apache/flink/table/planner/expressions/converter/converters/TemporalOverlapsConverter.java b/flink-table/flink-table-planner/src/main/java/org/apache/flink/table/planner/expressions/converter/converters/TemporalOverlapsConverter.java
index 38305c1..62d8846 100644
--- a/flink-table/flink-table-planner/src/main/java/org/apache/flink/table/planner/expressions/converter/converters/TemporalOverlapsConverter.java
+++ b/flink-table/flink-table-planner/src/main/java/org/apache/flink/table/planner/expressions/converter/converters/TemporalOverlapsConverter.java
@@ -18,6 +18,7 @@
 
 package org.apache.flink.table.planner.expressions.converter.converters;
 
+import org.apache.flink.annotation.Internal;
 import org.apache.flink.table.expressions.CallExpression;
 import org.apache.flink.table.functions.BuiltInFunctionDefinitions;
 import org.apache.flink.table.planner.expressions.converter.CallExpressionConvertRule;
@@ -32,6 +33,7 @@
 import static org.apache.flink.table.runtime.typeutils.TypeCheckUtils.isTimeInterval;
 
 /** Conversion for {@link BuiltInFunctionDefinitions#TEMPORAL_OVERLAPS}. */
+@Internal
 class TemporalOverlapsConverter extends CustomizedConverter {
     @Override
     public RexNode convert(CallExpression call, CallExpressionConvertRule.ConvertContext context) {
diff --git a/flink-table/flink-table-planner/src/main/java/org/apache/flink/table/planner/expressions/converter/converters/ThrowExceptionConverter.java b/flink-table/flink-table-planner/src/main/java/org/apache/flink/table/planner/expressions/converter/converters/ThrowExceptionConverter.java
index 440ad96..dce9da1 100644
--- a/flink-table/flink-table-planner/src/main/java/org/apache/flink/table/planner/expressions/converter/converters/ThrowExceptionConverter.java
+++ b/flink-table/flink-table-planner/src/main/java/org/apache/flink/table/planner/expressions/converter/converters/ThrowExceptionConverter.java
@@ -18,6 +18,7 @@
 
 package org.apache.flink.table.planner.expressions.converter.converters;
 
+import org.apache.flink.annotation.Internal;
 import org.apache.flink.table.expressions.CallExpression;
 import org.apache.flink.table.expressions.TypeLiteralExpression;
 import org.apache.flink.table.planner.expressions.converter.CallExpressionConvertRule;
@@ -30,6 +31,7 @@
 import static org.apache.flink.table.runtime.types.LogicalTypeDataTypeConverter.fromDataTypeToLogicalType;
 
 /** Conversion for {@link InternalFunctionDefinitions#THROW_EXCEPTION}. */
+@Internal
 class ThrowExceptionConverter extends CustomizedConverter {
     @Override
     public RexNode convert(CallExpression call, CallExpressionConvertRule.ConvertContext context) {
diff --git a/flink-table/flink-table-planner/src/main/java/org/apache/flink/table/planner/expressions/converter/converters/TimestampDiffConverter.java b/flink-table/flink-table-planner/src/main/java/org/apache/flink/table/planner/expressions/converter/converters/TimestampDiffConverter.java
index e61c448..2d5ad02 100644
--- a/flink-table/flink-table-planner/src/main/java/org/apache/flink/table/planner/expressions/converter/converters/TimestampDiffConverter.java
+++ b/flink-table/flink-table-planner/src/main/java/org/apache/flink/table/planner/expressions/converter/converters/TimestampDiffConverter.java
@@ -18,6 +18,7 @@
 
 package org.apache.flink.table.planner.expressions.converter.converters;
 
+import org.apache.flink.annotation.Internal;
 import org.apache.flink.table.expressions.CallExpression;
 import org.apache.flink.table.functions.BuiltInFunctionDefinitions;
 import org.apache.flink.table.planner.expressions.converter.CallExpressionConvertRule;
@@ -30,6 +31,7 @@
 import static org.apache.flink.table.planner.expressions.converter.ExpressionConverter.toRexNodes;
 
 /** Conversion for {@link BuiltInFunctionDefinitions#TIMESTAMP_DIFF}. */
+@Internal
 class TimestampDiffConverter extends CustomizedConverter {
     @Override
     public RexNode convert(CallExpression call, CallExpressionConvertRule.ConvertContext context) {
diff --git a/flink-table/flink-table-planner/src/main/java/org/apache/flink/table/planner/expressions/converter/converters/TrimConverter.java b/flink-table/flink-table-planner/src/main/java/org/apache/flink/table/planner/expressions/converter/converters/TrimConverter.java
index a8158da..07e7b5e 100644
--- a/flink-table/flink-table-planner/src/main/java/org/apache/flink/table/planner/expressions/converter/converters/TrimConverter.java
+++ b/flink-table/flink-table-planner/src/main/java/org/apache/flink/table/planner/expressions/converter/converters/TrimConverter.java
@@ -18,6 +18,7 @@
 
 package org.apache.flink.table.planner.expressions.converter.converters;
 
+import org.apache.flink.annotation.Internal;
 import org.apache.flink.table.expressions.CallExpression;
 import org.apache.flink.table.expressions.Expression;
 import org.apache.flink.table.expressions.ValueLiteralExpression;
@@ -33,6 +34,7 @@
 import static org.apache.flink.table.planner.expressions.converter.ExpressionConverter.extractValue;
 
 /** Conversion for {@link BuiltInFunctionDefinitions#TRIM}. */
+@Internal
 class TrimConverter extends CustomizedConverter {
     @Override
     public RexNode convert(CallExpression call, CallExpressionConvertRule.ConvertContext context) {