diff --git a/kernel/sql-federation/optimizer/src/main/java/org/apache/shardingsphere/sqlfederation/optimizer/converter/function/dialect/mysql/SQLExtensionOperatorTable.java b/kernel/sql-federation/optimizer/src/main/java/org/apache/shardingsphere/sqlfederation/optimizer/converter/operator/common/SQLExtensionOperatorTable.java
similarity index 93%
rename from kernel/sql-federation/optimizer/src/main/java/org/apache/shardingsphere/sqlfederation/optimizer/converter/function/dialect/mysql/SQLExtensionOperatorTable.java
rename to kernel/sql-federation/optimizer/src/main/java/org/apache/shardingsphere/sqlfederation/optimizer/converter/operator/common/SQLExtensionOperatorTable.java
index b9fe176593a5d..cfc8d3ced631a 100644
--- a/kernel/sql-federation/optimizer/src/main/java/org/apache/shardingsphere/sqlfederation/optimizer/converter/function/dialect/mysql/SQLExtensionOperatorTable.java
+++ b/kernel/sql-federation/optimizer/src/main/java/org/apache/shardingsphere/sqlfederation/optimizer/converter/operator/common/SQLExtensionOperatorTable.java
@@ -15,13 +15,14 @@
  * limitations under the License.
  */
 
-package org.apache.shardingsphere.sqlfederation.optimizer.converter.function.dialect.mysql;
+package org.apache.shardingsphere.sqlfederation.optimizer.converter.operator.common;
 
 import lombok.AccessLevel;
 import lombok.NoArgsConstructor;
 import org.apache.calcite.sql.SqlBinaryOperator;
 import org.apache.calcite.sql.SqlKind;
 import org.apache.calcite.sql.SqlPrefixOperator;
+import org.apache.shardingsphere.sqlfederation.optimizer.converter.operator.dialect.mysql.MySQLMatchAgainstOperator;
 
 /**
  * SQL extension operator table.
@@ -53,11 +54,11 @@ public final class SQLExtensionOperatorTable {
     
     public static final SqlBinaryOperator SOUNDS_LIKE = new SqlBinaryOperator("SOUNDS LIKE", SqlKind.OTHER, 30, true, null, null, null);
     
-    public static final MySQLMatchAgainstFunction MATCH_AGAINST = new MySQLMatchAgainstFunction();
-    
     public static final SqlBinaryOperator COLLATE = new SqlBinaryOperator("COLLATE", SqlKind.OTHER, 30, true, null, null, null);
     
     public static final SqlBinaryOperator ASSIGNMENT = new SqlBinaryOperator(":=", SqlKind.OTHER, 30, true, null, null, null);
     
     public static final SqlPrefixOperator TILDE = new SqlPrefixOperator("~", SqlKind.OTHER, 26, null, null, null);
+    
+    public static final MySQLMatchAgainstOperator MATCH_AGAINST = new MySQLMatchAgainstOperator();
 }
diff --git a/kernel/sql-federation/optimizer/src/main/java/org/apache/shardingsphere/sqlfederation/optimizer/converter/function/dialect/mysql/MySQLMatchAgainstFunction.java b/kernel/sql-federation/optimizer/src/main/java/org/apache/shardingsphere/sqlfederation/optimizer/converter/operator/dialect/mysql/MySQLMatchAgainstOperator.java
similarity index 94%
rename from kernel/sql-federation/optimizer/src/main/java/org/apache/shardingsphere/sqlfederation/optimizer/converter/function/dialect/mysql/MySQLMatchAgainstFunction.java
rename to kernel/sql-federation/optimizer/src/main/java/org/apache/shardingsphere/sqlfederation/optimizer/converter/operator/dialect/mysql/MySQLMatchAgainstOperator.java
index 66ae68cee85bd..3b3a8e8e1f816 100644
--- a/kernel/sql-federation/optimizer/src/main/java/org/apache/shardingsphere/sqlfederation/optimizer/converter/function/dialect/mysql/MySQLMatchAgainstFunction.java
+++ b/kernel/sql-federation/optimizer/src/main/java/org/apache/shardingsphere/sqlfederation/optimizer/converter/operator/dialect/mysql/MySQLMatchAgainstOperator.java
@@ -15,7 +15,7 @@
  * limitations under the License.
  */
 
-package org.apache.shardingsphere.sqlfederation.optimizer.converter.function.dialect.mysql;
+package org.apache.shardingsphere.sqlfederation.optimizer.converter.operator.dialect.mysql;
 
 import org.apache.calcite.sql.SqlCall;
 import org.apache.calcite.sql.SqlFunction;
@@ -38,13 +38,13 @@
 import java.util.List;
 
 /**
- * MySQL match against function.
+ * MySQL match against operator.
  */
-public final class MySQLMatchAgainstFunction extends SqlFunction {
+public final class MySQLMatchAgainstOperator extends SqlFunction {
     
     private static final FrameType FRAME_TYPE = FrameTypeEnum.create("MATCH");
     
-    public MySQLMatchAgainstFunction() {
+    public MySQLMatchAgainstOperator() {
         super("MATCH_AGAINST", SqlKind.OTHER_FUNCTION, ReturnTypes.DOUBLE, InferTypes.FIRST_KNOWN, OperandTypes.ANY, SqlFunctionCategory.STRING);
     }
     
diff --git a/kernel/sql-federation/optimizer/src/main/java/org/apache/shardingsphere/sqlfederation/optimizer/converter/segment/expression/impl/BinaryOperationExpressionConverter.java b/kernel/sql-federation/optimizer/src/main/java/org/apache/shardingsphere/sqlfederation/optimizer/converter/segment/expression/impl/BinaryOperationExpressionConverter.java
index 0bd603693b075..5785bfd500e2f 100644
--- a/kernel/sql-federation/optimizer/src/main/java/org/apache/shardingsphere/sqlfederation/optimizer/converter/segment/expression/impl/BinaryOperationExpressionConverter.java
+++ b/kernel/sql-federation/optimizer/src/main/java/org/apache/shardingsphere/sqlfederation/optimizer/converter/segment/expression/impl/BinaryOperationExpressionConverter.java
@@ -29,7 +29,7 @@
 import org.apache.commons.collections4.map.CaseInsensitiveMap;
 import org.apache.shardingsphere.sql.parser.sql.common.segment.dml.expr.BinaryOperationExpression;
 import org.apache.shardingsphere.sql.parser.sql.common.segment.dml.expr.simple.LiteralExpressionSegment;
-import org.apache.shardingsphere.sqlfederation.optimizer.converter.function.dialect.mysql.SQLExtensionOperatorTable;
+import org.apache.shardingsphere.sqlfederation.optimizer.converter.operator.common.SQLExtensionOperatorTable;
 import org.apache.shardingsphere.sqlfederation.optimizer.converter.segment.expression.ExpressionConverter;
 
 import java.util.Collections;
diff --git a/kernel/sql-federation/optimizer/src/main/java/org/apache/shardingsphere/sqlfederation/optimizer/converter/segment/expression/impl/CollateExpressionConverter.java b/kernel/sql-federation/optimizer/src/main/java/org/apache/shardingsphere/sqlfederation/optimizer/converter/segment/expression/impl/CollateExpressionConverter.java
index e53b0dde51637..426fb8915535d 100644
--- a/kernel/sql-federation/optimizer/src/main/java/org/apache/shardingsphere/sqlfederation/optimizer/converter/segment/expression/impl/CollateExpressionConverter.java
+++ b/kernel/sql-federation/optimizer/src/main/java/org/apache/shardingsphere/sqlfederation/optimizer/converter/segment/expression/impl/CollateExpressionConverter.java
@@ -24,7 +24,7 @@
 import org.apache.calcite.sql.SqlNodeList;
 import org.apache.calcite.sql.parser.SqlParserPos;
 import org.apache.shardingsphere.sql.parser.sql.common.segment.dml.expr.CollateExpression;
-import org.apache.shardingsphere.sqlfederation.optimizer.converter.function.dialect.mysql.SQLExtensionOperatorTable;
+import org.apache.shardingsphere.sqlfederation.optimizer.converter.operator.common.SQLExtensionOperatorTable;
 import org.apache.shardingsphere.sqlfederation.optimizer.converter.segment.expression.ExpressionConverter;
 
 import java.util.LinkedList;
diff --git a/kernel/sql-federation/optimizer/src/main/java/org/apache/shardingsphere/sqlfederation/optimizer/converter/segment/expression/impl/MatchExpressionConverter.java b/kernel/sql-federation/optimizer/src/main/java/org/apache/shardingsphere/sqlfederation/optimizer/converter/segment/expression/impl/MatchExpressionConverter.java
index d1e6e4953018d..69ebb4d7a4911 100644
--- a/kernel/sql-federation/optimizer/src/main/java/org/apache/shardingsphere/sqlfederation/optimizer/converter/segment/expression/impl/MatchExpressionConverter.java
+++ b/kernel/sql-federation/optimizer/src/main/java/org/apache/shardingsphere/sqlfederation/optimizer/converter/segment/expression/impl/MatchExpressionConverter.java
@@ -26,7 +26,7 @@
 import org.apache.calcite.sql.parser.SqlParserPos;
 import org.apache.shardingsphere.sql.parser.sql.dialect.segment.mysql.match.MatchAgainstExpression;
 import org.apache.shardingsphere.sql.parser.sql.common.segment.generic.OwnerSegment;
-import org.apache.shardingsphere.sqlfederation.optimizer.converter.function.dialect.mysql.SQLExtensionOperatorTable;
+import org.apache.shardingsphere.sqlfederation.optimizer.converter.operator.common.SQLExtensionOperatorTable;
 import org.apache.shardingsphere.sqlfederation.optimizer.converter.segment.expression.ExpressionConverter;
 
 import java.util.ArrayList;
diff --git a/kernel/sql-federation/optimizer/src/main/java/org/apache/shardingsphere/sqlfederation/optimizer/converter/segment/expression/impl/NotExpressionConverter.java b/kernel/sql-federation/optimizer/src/main/java/org/apache/shardingsphere/sqlfederation/optimizer/converter/segment/expression/impl/NotExpressionConverter.java
index b7d46c4bf55f6..cc5c98853056d 100644
--- a/kernel/sql-federation/optimizer/src/main/java/org/apache/shardingsphere/sqlfederation/optimizer/converter/segment/expression/impl/NotExpressionConverter.java
+++ b/kernel/sql-federation/optimizer/src/main/java/org/apache/shardingsphere/sqlfederation/optimizer/converter/segment/expression/impl/NotExpressionConverter.java
@@ -24,7 +24,7 @@
 import org.apache.calcite.sql.fun.SqlStdOperatorTable;
 import org.apache.calcite.sql.parser.SqlParserPos;
 import org.apache.shardingsphere.sql.parser.sql.common.segment.dml.expr.NotExpression;
-import org.apache.shardingsphere.sqlfederation.optimizer.converter.function.dialect.mysql.SQLExtensionOperatorTable;
+import org.apache.shardingsphere.sqlfederation.optimizer.converter.operator.common.SQLExtensionOperatorTable;
 import org.apache.shardingsphere.sqlfederation.optimizer.converter.segment.expression.ExpressionConverter;
 
 import java.util.LinkedList;
diff --git a/kernel/sql-federation/optimizer/src/main/java/org/apache/shardingsphere/sqlfederation/optimizer/converter/segment/expression/impl/UnaryOperationExpressionConverter.java b/kernel/sql-federation/optimizer/src/main/java/org/apache/shardingsphere/sqlfederation/optimizer/converter/segment/expression/impl/UnaryOperationExpressionConverter.java
index 93035e7f218f5..9110e916aa567 100644
--- a/kernel/sql-federation/optimizer/src/main/java/org/apache/shardingsphere/sqlfederation/optimizer/converter/segment/expression/impl/UnaryOperationExpressionConverter.java
+++ b/kernel/sql-federation/optimizer/src/main/java/org/apache/shardingsphere/sqlfederation/optimizer/converter/segment/expression/impl/UnaryOperationExpressionConverter.java
@@ -27,7 +27,7 @@
 import org.apache.calcite.sql.parser.SqlParserPos;
 import org.apache.commons.collections4.map.CaseInsensitiveMap;
 import org.apache.shardingsphere.sql.parser.sql.common.segment.dml.expr.UnaryOperationExpression;
-import org.apache.shardingsphere.sqlfederation.optimizer.converter.function.dialect.mysql.SQLExtensionOperatorTable;
+import org.apache.shardingsphere.sqlfederation.optimizer.converter.operator.common.SQLExtensionOperatorTable;
 import org.apache.shardingsphere.sqlfederation.optimizer.converter.segment.expression.ExpressionConverter;
 
 import java.util.LinkedList;
diff --git a/kernel/sql-federation/optimizer/src/main/java/org/apache/shardingsphere/sqlfederation/optimizer/converter/statement/merge/MergeStatementConverter.java b/kernel/sql-federation/optimizer/src/main/java/org/apache/shardingsphere/sqlfederation/optimizer/converter/statement/merge/MergeStatementConverter.java
index 91aa2fadcc658..1c6708598d723 100644
--- a/kernel/sql-federation/optimizer/src/main/java/org/apache/shardingsphere/sqlfederation/optimizer/converter/statement/merge/MergeStatementConverter.java
+++ b/kernel/sql-federation/optimizer/src/main/java/org/apache/shardingsphere/sqlfederation/optimizer/converter/statement/merge/MergeStatementConverter.java
@@ -44,7 +44,7 @@ public final class MergeStatementConverter implements SQLStatementConverter<Merg
     @Override
     public SqlNode convert(final MergeStatement mergeStatement) {
         SqlNode targetTable = TableConverter.convert(mergeStatement.getTarget()).orElseThrow(IllegalStateException::new);
-        SqlNode condition = ExpressionConverter.convert(mergeStatement.getExpression().getExpr()).get();
+        SqlNode condition = ExpressionConverter.convert(mergeStatement.getExpression().getExpr()).orElseThrow(IllegalStateException::new);
         SqlNode sourceTable = TableConverter.convert(mergeStatement.getSource()).orElseThrow(IllegalStateException::new);
         SqlUpdate sqlUpdate = null;
         if (null != mergeStatement.getUpdate()) {
diff --git a/test/it/optimizer/src/test/resources/converter/select-join.xml b/test/it/optimizer/src/test/resources/converter/select-join.xml
index 704b5f40dcc02..707f0be67fb73 100644
--- a/test/it/optimizer/src/test/resources/converter/select-join.xml
+++ b/test/it/optimizer/src/test/resources/converter/select-join.xml
@@ -45,5 +45,6 @@
     <test-cases sql-case-id="select_natural_right_join" expected-sql="SELECT * FROM &quot;t_order&quot; AS &quot;o&quot; NATURAL RIGHT JOIN &quot;t_order_item&quot; AS &quot;i&quot; WHERE &quot;o&quot;.&quot;order_id&quot; = ?" db-types="PostgreSQL,openGauss" sql-case-types="PLACEHOLDER" />
     <test-cases sql-case-id="select_natural_full_join" expected-sql="SELECT * FROM &quot;t_order&quot; AS &quot;o&quot; NATURAL FULL JOIN &quot;t_order_item&quot; AS &quot;i&quot; WHERE &quot;o&quot;.&quot;order_id&quot; = 1" db-types="PostgreSQL,openGauss" sql-case-types="LITERAL" />
     <test-cases sql-case-id="select_natural_full_join" expected-sql="SELECT * FROM &quot;t_order&quot; AS &quot;o&quot; NATURAL FULL JOIN &quot;t_order_item&quot; AS &quot;i&quot; WHERE &quot;o&quot;.&quot;order_id&quot; = ?" db-types="PostgreSQL,openGauss" sql-case-types="PLACEHOLDER" />
-    <test-cases sql-case-id="select_with_join_operator" expected-sql="SELECT * FROM t_order o , t_order_item i WHERE o.order_id(+) = i.order_id" db-types="Oracle" />
+    <!-- FIXME support this case when calcite support oracle outer join -->
+    <!--<test-cases sql-case-id="select_with_join_operator" expected-sql="SELECT * FROM t_order o , t_order_item i WHERE o.order_id(+) = i.order_id" db-types="Oracle" />-->
 </sql-node-converter-test-cases>