diff --git a/fe/src/com/baidu/palo/analysis/Analyzer.java b/fe/src/com/baidu/palo/analysis/Analyzer.java
index 5b071819b87f99..ba2126d855b9c6 100644
--- a/fe/src/com/baidu/palo/analysis/Analyzer.java
+++ b/fe/src/com/baidu/palo/analysis/Analyzer.java
@@ -24,6 +24,7 @@
 import com.baidu.palo.catalog.Catalog;
 import com.baidu.palo.catalog.Column;
 import com.baidu.palo.catalog.Database;
+import com.baidu.palo.catalog.InfoSchemaDb;
 import com.baidu.palo.catalog.Table;
 import com.baidu.palo.cluster.ClusterNamespace;
 import com.baidu.palo.catalog.Type;
@@ -525,6 +526,10 @@ public SlotDescriptor registerColumnRef(TableName tblName, String colName) throw
         if (tblName == null) {
             d = resolveColumnRef(colName);
         } else {
+            if (InfoSchemaDb.isInfoSchemaDb(tblName.getDb()) ||
+                    (tblName.getDb() == null && InfoSchemaDb.isInfoSchemaDb(getDefaultDb()))) {
+                tblName = new TableName(tblName.getDb(), tblName.getTbl().toLowerCase());
+            }
             d = resolveColumnRef(tblName, colName);
         }
         if (d == null && hasAncestors() && isSubquery) {
diff --git a/fe/src/com/baidu/palo/analysis/ExprSubstitutionMap.java b/fe/src/com/baidu/palo/analysis/ExprSubstitutionMap.java
index 1a5c6c131a9359..f74f2f7d94b606 100644
--- a/fe/src/com/baidu/palo/analysis/ExprSubstitutionMap.java
+++ b/fe/src/com/baidu/palo/analysis/ExprSubstitutionMap.java
@@ -49,9 +49,9 @@ public ExprSubstitutionMap() {
     }
 
     // Only used to convert show statement to select statement
-    public ExprSubstitutionMap(boolean check_analyzed) {
+    public ExprSubstitutionMap(boolean checkAnalyzed) {
         this(Lists.<Expr>newArrayList(), Lists.<Expr>newArrayList());
-        this.checkAnalyzed_ = false;
+        this.checkAnalyzed_ = checkAnalyzed;
     }
 
     public ExprSubstitutionMap(List<Expr> lhs, List<Expr> rhs) {
diff --git a/fe/src/com/baidu/palo/analysis/ShowVariablesStmt.java b/fe/src/com/baidu/palo/analysis/ShowVariablesStmt.java
index 2fd85be6cd1984..9341077acb3d5a 100644
--- a/fe/src/com/baidu/palo/analysis/ShowVariablesStmt.java
+++ b/fe/src/com/baidu/palo/analysis/ShowVariablesStmt.java
@@ -82,7 +82,7 @@ public SelectStmt toSelectStmt(Analyzer analyzer) {
         analyze(analyzer);
         // Columns
         SelectList selectList = new SelectList();
-        ExprSubstitutionMap aliasMap = new ExprSubstitutionMap();
+        ExprSubstitutionMap aliasMap = new ExprSubstitutionMap(false);
         TableName tableName = null;
         if (type == SetType.GLOBAL) {
             tableName = new TableName(InfoSchemaDb.getDatabaseName(), "GLOBAL_VARIABLES");
diff --git a/fe/src/com/baidu/palo/catalog/InfoSchemaDb.java b/fe/src/com/baidu/palo/catalog/InfoSchemaDb.java
index 24a2f0c31c4a55..a06c4dfc414dd4 100644
--- a/fe/src/com/baidu/palo/catalog/InfoSchemaDb.java
+++ b/fe/src/com/baidu/palo/catalog/InfoSchemaDb.java
@@ -90,4 +90,15 @@ public Table getTable(String name) {
     public static String getFullInfoSchemaDbName(String cluster) {
         return ClusterNamespace.getDbFullName(cluster, DATABASE_NAME);
     }
+
+    public static boolean isInfoSchemaDb(String dbName) {
+        if (dbName == null) {
+            return false;
+        }
+        String[] ele = dbName.split(ClusterNamespace.CLUSTER_DELIMITER);
+        if (ele.length == 2) {
+            dbName = ele[1];
+        }
+        return DATABASE_NAME.equalsIgnoreCase(dbName);
+    }
 }