diff --git a/headless/core/src/main/java/com/tencent/supersonic/headless/core/translator/parser/calcite/SemanticNode.java b/headless/core/src/main/java/com/tencent/supersonic/headless/core/translator/parser/calcite/SemanticNode.java
index 9f85d4abb..8757d3e6d 100644
--- a/headless/core/src/main/java/com/tencent/supersonic/headless/core/translator/parser/calcite/SemanticNode.java
+++ b/headless/core/src/main/java/com/tencent/supersonic/headless/core/translator/parser/calcite/SemanticNode.java
@@ -78,7 +78,8 @@ public static SqlNode parse(String expression, SqlValidatorScope scope, EngineTy
                 scope.getValidator().getCatalogReader().getRootSchema(), engineType);
         if (Configuration.getSqlAdvisor(sqlValidatorWithHints, engineType).getReservedAndKeyWords()
                 .contains(expression.toUpperCase())) {
-            if (engineType == EngineType.HANADB || engineType == EngineType.PRESTO || engineType == EngineType.TRINO) {
+            if (engineType == EngineType.HANADB || engineType == EngineType.PRESTO
+                    || engineType == EngineType.TRINO) {
                 expression = String.format("\"%s\"", expression);
             } else {
                 expression = String.format("`%s`", expression);
@@ -166,9 +167,9 @@ public static SqlNode getTable(SqlNode sqlNode) {
         if (sqlNode instanceof SqlBasicCall) {
             SqlBasicCall sqlBasicCall = (SqlBasicCall) sqlNode;
             if (sqlBasicCall.getOperator().getKind().equals(SqlKind.AS)) {
-                if (sqlBasicCall.getOperandList().get(0) instanceof SqlSelect) {
-                    SqlSelect table = (SqlSelect) sqlBasicCall.getOperandList().get(0);
-                    return table;
+                SqlNode innerQuery = sqlBasicCall.getOperandList().get(0);
+                if (innerQuery instanceof SqlCall) {
+                    return innerQuery;
                 }
             }
         }
diff --git a/headless/core/src/main/java/com/tencent/supersonic/headless/core/translator/parser/calcite/SqlBuilder.java b/headless/core/src/main/java/com/tencent/supersonic/headless/core/translator/parser/calcite/SqlBuilder.java
index 3617d6df4..b9db3dc5d 100644
--- a/headless/core/src/main/java/com/tencent/supersonic/headless/core/translator/parser/calcite/SqlBuilder.java
+++ b/headless/core/src/main/java/com/tencent/supersonic/headless/core/translator/parser/calcite/SqlBuilder.java
@@ -69,7 +69,13 @@ public String buildOntologySql(QueryStatement queryStatement) throws Exception {
         SqlNode parserNode = tableView.build();
         DatabaseResp database = queryStatement.getOntology().getDatabase();
         EngineType engineType = EngineType.fromString(database.getType());
-        parserNode = optimizeParseNode(parserNode, engineType);
+        try {
+            parserNode = optimizeParseNode(parserNode, engineType);
+        } catch (Exception e) {
+            // failure in optimization phase doesn't affect the query result,
+            // just ignore it
+            log.error("optimizeParseNode error", e);
+        }
         return SemanticNode.getSql(parserNode, engineType);
     }