diff --git a/src/main/java/com/alibaba/druid/sql/dialect/postgresql/ast/PGAggregateExpr.java b/src/main/java/com/alibaba/druid/sql/dialect/postgresql/ast/PGAggregateExpr.java
new file mode 100644
index 0000000000..390aed24a9
--- /dev/null
+++ b/src/main/java/com/alibaba/druid/sql/dialect/postgresql/ast/PGAggregateExpr.java
@@ -0,0 +1,66 @@
+package com.alibaba.druid.sql.dialect.postgresql.ast;
+
+import com.alibaba.druid.sql.ast.SQLExpr;
+import com.alibaba.druid.sql.ast.expr.SQLAggregateExpr;
+import com.alibaba.druid.sql.dialect.postgresql.ast.expr.PGAnalytic;
+import com.alibaba.druid.sql.dialect.postgresql.visitor.PGASTVisitor;
+import com.alibaba.druid.sql.visitor.SQLASTVisitor;
+
+public class PGAggregateExpr extends SQLAggregateExpr implements PGSQLObject {
+
+	private PGAnalytic    over;
+	
+	public PGAnalytic getOver() {
+		return over;
+	}
+
+	public void setOver(PGAnalytic over) {
+		this.over = over;
+	}
+
+	private static final long serialVersionUID = 1L;
+
+	public PGAggregateExpr(String methodName, int option) {
+		super(methodName, option);
+	}
+
+	public PGAggregateExpr(String methodName) {
+		super(methodName);
+	}
+	
+    public void output(StringBuffer buf) {
+        buf.append(this.methodName);
+        buf.append("(");
+        int i = 0;
+        for (int size = this.arguments.size(); i < size; ++i) {
+            ((SQLExpr) this.arguments.get(i)).output(buf);
+        }
+        buf.append(")");
+
+        if (this.over != null) {
+            buf.append(" ");
+            this.over.output(buf);
+        }
+    }
+
+	@Override
+    protected void accept0(SQLASTVisitor visitor) {
+        if (visitor instanceof PGASTVisitor) {
+            this.accept0((PGASTVisitor) visitor);
+        } else {
+            if (visitor.visit(this)) {
+                acceptChild(visitor, this.arguments);
+                acceptChild(visitor, this.over);
+            }
+            visitor.endVisit(this);
+        }
+    }
+
+    public void accept0(PGASTVisitor visitor) {
+    	if (visitor.visit(this)) {
+    		acceptChild(visitor, this.arguments);
+    		acceptChild(visitor, this.over);
+    	}
+    	visitor.endVisit(this);
+    }
+}
diff --git a/src/main/java/com/alibaba/druid/sql/dialect/postgresql/ast/PGAnalyticWindowing.java b/src/main/java/com/alibaba/druid/sql/dialect/postgresql/ast/PGAnalyticWindowing.java
new file mode 100644
index 0000000000..852a93b62e
--- /dev/null
+++ b/src/main/java/com/alibaba/druid/sql/dialect/postgresql/ast/PGAnalyticWindowing.java
@@ -0,0 +1,67 @@
+/*
+ * Copyright 1999-2011 Alibaba Group Holding Ltd.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package com.alibaba.druid.sql.dialect.postgresql.ast;
+
+import com.alibaba.druid.sql.ast.SQLExpr;
+import com.alibaba.druid.sql.ast.SQLObjectImpl;
+import com.alibaba.druid.sql.dialect.oracle.visitor.OracleASTVisitor;
+import com.alibaba.druid.sql.dialect.postgresql.ast.expr.PGExpr;
+import com.alibaba.druid.sql.dialect.postgresql.visitor.PGASTVisitor;
+import com.alibaba.druid.sql.visitor.SQLASTVisitor;
+
+@SuppressWarnings("serial")
+public class PGAnalyticWindowing extends SQLObjectImpl implements PGExpr {
+
+    private Type    type;
+    private SQLExpr expr;
+
+    public PGAnalyticWindowing(){
+
+    }
+
+    @Override
+    protected void accept0(SQLASTVisitor visitor) {
+        this.accept0((PGASTVisitor) visitor);
+    }
+
+    public void accept0(PGASTVisitor visitor) {
+    	//TODO
+//        if (visitor.visit(this)) {
+//            acceptChild(visitor, this.expr);
+//        }
+//        visitor.endVisit(this);
+    }
+
+    public SQLExpr getExpr() {
+        return this.expr;
+    }
+
+    public void setExpr(SQLExpr expr) {
+        this.expr = expr;
+    }
+
+    public Type getType() {
+        return this.type;
+    }
+
+    public void setType(Type type) {
+        this.type = type;
+    }
+
+    public static enum Type {
+        ROWS, RANGE;
+    }
+}
diff --git a/src/main/java/com/alibaba/druid/sql/dialect/postgresql/ast/PGOrderBy.java b/src/main/java/com/alibaba/druid/sql/dialect/postgresql/ast/PGOrderBy.java
new file mode 100644
index 0000000000..636f31646f
--- /dev/null
+++ b/src/main/java/com/alibaba/druid/sql/dialect/postgresql/ast/PGOrderBy.java
@@ -0,0 +1,53 @@
+package com.alibaba.druid.sql.dialect.postgresql.ast;
+
+import com.alibaba.druid.sql.ast.SQLOrderBy;
+import com.alibaba.druid.sql.dialect.postgresql.visitor.PGASTVisitor;
+import com.alibaba.druid.sql.visitor.SQLASTVisitor;
+
+public class PGOrderBy extends SQLOrderBy {
+    private static final long serialVersionUID = 1L;
+
+    private boolean           sibings;
+
+
+
+    public boolean isSibings() {
+        return this.sibings;
+    }
+
+    public void setSibings(boolean sibings) {
+        this.sibings = sibings;
+    }
+
+    protected void accept0(SQLASTVisitor visitor) {
+        if (visitor instanceof PGASTVisitor) {
+            accept0((PGASTVisitor) visitor);
+        } else {
+            super.accept0(visitor);
+        }
+    }
+
+    protected void accept0(PGASTVisitor visitor) {
+        if (visitor.visit(this)) {
+            acceptChild(visitor, this.items);
+        }
+
+        visitor.endVisit(this);
+    }
+
+    public void output(StringBuffer buf) {
+        buf.append("ORDER ");
+        if (this.sibings) {
+            buf.append("SIBLINGS ");
+        }
+        buf.append("BY ");
+
+        int i = 0;
+        for (int size = this.items.size(); i < size; ++i) {
+            if (i != 0) {
+                buf.append(", ");
+            }
+            ((PGOrderByItem) this.items.get(i)).output(buf);
+        }
+    }
+}
diff --git a/src/main/java/com/alibaba/druid/sql/dialect/postgresql/ast/PGOrderByItem.java b/src/main/java/com/alibaba/druid/sql/dialect/postgresql/ast/PGOrderByItem.java
new file mode 100644
index 0000000000..5994489ff8
--- /dev/null
+++ b/src/main/java/com/alibaba/druid/sql/dialect/postgresql/ast/PGOrderByItem.java
@@ -0,0 +1,87 @@
+/*
+ * Copyright 1999-2011 Alibaba Group Holding Ltd.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package com.alibaba.druid.sql.dialect.postgresql.ast;
+
+import com.alibaba.druid.sql.ast.SQLOrderingSpecification;
+import com.alibaba.druid.sql.ast.statement.SQLSelectOrderByItem;
+import com.alibaba.druid.sql.dialect.postgresql.visitor.PGASTVisitor;
+import com.alibaba.druid.sql.visitor.SQLASTVisitor;
+
+public class PGOrderByItem extends SQLSelectOrderByItem {
+
+    private static final long serialVersionUID = 1L;
+
+    private NullsOrderType    nullsOrderType;
+
+    public PGOrderByItem(){
+
+    }
+
+    public NullsOrderType getNullsOrderType() {
+        return this.nullsOrderType;
+    }
+
+    public void setNullsOrderType(NullsOrderType nullsOrderType) {
+        this.nullsOrderType = nullsOrderType;
+    }
+
+    protected void accept0(SQLASTVisitor visitor) {
+        if (visitor instanceof PGASTVisitor) {
+            accept0((PGASTVisitor) visitor);
+        } else {
+            super.accept0(visitor);
+        }
+    }
+
+    protected void accept0(PGASTVisitor visitor) {
+        if (visitor.visit(this)) {
+            acceptChild(visitor, this.expr);
+        }
+
+        visitor.endVisit(this);
+    }
+
+    public void output(StringBuffer buf) {
+        this.expr.output(buf);
+        if (SQLOrderingSpecification.ASC.equals(this.type)) {
+            buf.append(" ASC");
+        } else if (SQLOrderingSpecification.DESC.equals(this.type)) {
+            buf.append(" DESC");
+        }
+        if (NullsOrderType.NullsFirst.equals(this.nullsOrderType)) {
+            buf.append(" NULLS FIRST");
+        } else if (NullsOrderType.NullsLast.equals(this.nullsOrderType)) {
+            buf.append(" NULLS LAST");
+        }
+    }
+
+    public static enum NullsOrderType {
+        NullsFirst, NullsLast;
+
+        public String toFormalString() {
+            if (NullsFirst.equals(this)) {
+                return "NULLS FIRST";
+            }
+
+            if (NullsLast.equals(this)) {
+                return "NULLS LAST";
+            }
+
+            throw new IllegalArgumentException();
+        }
+    }
+
+}
diff --git a/src/main/java/com/alibaba/druid/sql/dialect/postgresql/ast/expr/PGAnalytic.java b/src/main/java/com/alibaba/druid/sql/dialect/postgresql/ast/expr/PGAnalytic.java
new file mode 100644
index 0000000000..ee8c572f11
--- /dev/null
+++ b/src/main/java/com/alibaba/druid/sql/dialect/postgresql/ast/expr/PGAnalytic.java
@@ -0,0 +1,64 @@
+/*
+ * Copyright 1999-2011 Alibaba Group Holding Ltd.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package com.alibaba.druid.sql.dialect.postgresql.ast.expr;
+
+import java.util.ArrayList;
+import java.util.List;
+
+import com.alibaba.druid.sql.ast.SQLExpr;
+import com.alibaba.druid.sql.ast.SQLObjectImpl;
+import com.alibaba.druid.sql.dialect.postgresql.ast.PGAnalyticWindowing;
+import com.alibaba.druid.sql.dialect.postgresql.ast.PGOrderBy;
+import com.alibaba.druid.sql.dialect.postgresql.visitor.PGASTVisitor;
+import com.alibaba.druid.sql.visitor.SQLASTVisitor;
+
+public class PGAnalytic extends SQLObjectImpl implements PGExpr {
+
+    private static final long       serialVersionUID = 1L;
+    private final List<SQLExpr>     partitionBy      = new ArrayList<SQLExpr>();
+    private PGOrderBy           orderBy;
+
+
+	public PGOrderBy getOrderBy() {
+		return orderBy;
+	}
+
+	public void setOrderBy(PGOrderBy orderBy) {
+		this.orderBy = orderBy;
+	}
+
+	public PGAnalytic(){
+
+    }
+
+    @Override
+    protected void accept0(SQLASTVisitor visitor) {
+        this.accept0((PGASTVisitor) visitor);
+    }
+
+    public void accept0(PGASTVisitor visitor) {
+//        if (visitor.visit(this)) {
+//            acceptChild(visitor, this.partitionBy);
+//            acceptChild(visitor, this.orderBy);
+//        }
+//        visitor.endVisit(this);
+    }
+
+
+    public List<SQLExpr> getPartitionBy() {
+        return this.partitionBy;
+    }
+}
diff --git a/src/main/java/com/alibaba/druid/sql/dialect/postgresql/ast/expr/PGExpr.java b/src/main/java/com/alibaba/druid/sql/dialect/postgresql/ast/expr/PGExpr.java
new file mode 100644
index 0000000000..7d08a58e5b
--- /dev/null
+++ b/src/main/java/com/alibaba/druid/sql/dialect/postgresql/ast/expr/PGExpr.java
@@ -0,0 +1,8 @@
+package com.alibaba.druid.sql.dialect.postgresql.ast.expr;
+
+import com.alibaba.druid.sql.ast.SQLExpr;
+import com.alibaba.druid.sql.dialect.postgresql.ast.PGSQLObject;
+
+public interface PGExpr extends SQLExpr, PGSQLObject{
+
+}
diff --git a/src/main/java/com/alibaba/druid/sql/dialect/postgresql/parser/PGExprParser.java b/src/main/java/com/alibaba/druid/sql/dialect/postgresql/parser/PGExprParser.java
new file mode 100644
index 0000000000..945a2393c0
--- /dev/null
+++ b/src/main/java/com/alibaba/druid/sql/dialect/postgresql/parser/PGExprParser.java
@@ -0,0 +1,99 @@
+package com.alibaba.druid.sql.dialect.postgresql.parser;
+
+import com.alibaba.druid.sql.ast.expr.SQLAggregateExpr;
+import com.alibaba.druid.sql.ast.expr.SQLIdentifierExpr;
+import com.alibaba.druid.sql.dialect.oracle.ast.OracleOrderBy;
+import com.alibaba.druid.sql.dialect.oracle.ast.expr.OracleAnalyticWindowing;
+import com.alibaba.druid.sql.dialect.postgresql.ast.PGAggregateExpr;
+import com.alibaba.druid.sql.dialect.postgresql.ast.PGOrderBy;
+import com.alibaba.druid.sql.dialect.postgresql.ast.expr.PGAnalytic;
+import com.alibaba.druid.sql.parser.Lexer;
+import com.alibaba.druid.sql.parser.ParserException;
+import com.alibaba.druid.sql.parser.SQLExprParser;
+import com.alibaba.druid.sql.parser.Token;
+
+public class PGExprParser extends SQLExprParser{
+    public PGExprParser(String sql) throws ParserException{
+        super(sql);
+    }
+
+    public PGExprParser(Lexer lexer){
+        super(lexer);
+    }
+    
+    protected SQLAggregateExpr parseAggregateExpr(String method_name) throws ParserException {
+        PGAggregateExpr aggregateExpr;
+        if (lexer.token() == Token.ALL) {
+            aggregateExpr = new PGAggregateExpr(method_name, 1);
+            lexer.nextToken();
+        } else if (lexer.token() == Token.DISTINCT) {
+            aggregateExpr = new PGAggregateExpr(method_name, 0);
+            lexer.nextToken();
+        } else {
+            aggregateExpr = new PGAggregateExpr(method_name, 1);
+        }
+
+        exprList(aggregateExpr.getArguments());
+
+        accept(Token.RPAREN);
+        
+        if (lexer.token() == Token.OVER) {
+        	lexer.nextToken();
+        	PGAnalytic over = new PGAnalytic();
+        	accept(Token.LPAREN);
+        	
+            if (identifierEquals("PARTITION")) {
+                lexer.nextToken();
+                accept(Token.BY);
+
+                if (lexer.token() == (Token.LPAREN)) {
+                    lexer.nextToken();
+                    exprList(over.getPartitionBy());
+                    accept(Token.RPAREN);
+                } else {
+                    exprList(over.getPartitionBy());
+                }
+            }
+
+
+            over.setOrderBy(parseOrderBy());
+            
+            if (over.getOrderBy() != null) {
+            	//TODO window
+            }
+        	
+        	accept(Token.RPAREN);
+        	aggregateExpr.setOver(over);
+
+        }
+        
+        return aggregateExpr;
+    }
+    
+    
+    @Override
+    public PGOrderBy parseOrderBy() {
+        if (lexer.token() == (Token.ORDER)) {
+        	PGOrderBy orderBy = new PGOrderBy();
+            lexer.nextToken();
+
+            if (identifierEquals("SIBLINGS")) {
+                lexer.nextToken();
+                orderBy.setSibings(true);
+            }
+
+            accept(Token.BY);
+
+            orderBy.getItems().add(parseSelectOrderByItem());
+
+            while (lexer.token() == (Token.COMMA)) {
+                lexer.nextToken();
+                orderBy.getItems().add(parseSelectOrderByItem());
+            }
+
+            return orderBy;
+        }
+
+        return null;
+    }
+}
diff --git a/src/test/java/com/alibaba/druid/bvt/proxy/filter/MergeStatFilterTest3.java b/src/test/java/com/alibaba/druid/bvt/proxy/filter/MergeStatFilterTest3.java
new file mode 100644
index 0000000000..f74fa25fa7
--- /dev/null
+++ b/src/test/java/com/alibaba/druid/bvt/proxy/filter/MergeStatFilterTest3.java
@@ -0,0 +1,48 @@
+package com.alibaba.druid.bvt.proxy.filter;
+
+import java.io.InputStreamReader;
+import java.sql.Connection;
+import java.sql.Statement;
+
+import junit.framework.Assert;
+import junit.framework.TestCase;
+
+import com.alibaba.druid.pool.DruidDataSource;
+import com.alibaba.druid.sql.SQLUtils;
+import com.alibaba.druid.util.IOUtils;
+
+public class MergeStatFilterTest3 extends TestCase {
+	private DruidDataSource dataSource;
+
+	protected void setUp() throws Exception {
+		dataSource = new DruidDataSource();
+		dataSource.setUrl("jdbc:mock:xx");
+		dataSource.setFilters("mergeStat");
+		dataSource.setDbType("postgresql");
+	}
+
+	protected void tearDown() throws Exception {
+		dataSource.close();
+	}
+
+	public void test_merge() throws Exception {
+		String sql = IOUtils.read(new InputStreamReader(this.getClass().getResourceAsStream("/bvt/parser/postgresql.txt")));
+		//System.out.println(sql);
+		{
+			Connection conn = dataSource.getConnection();
+
+			Statement stmt = conn.createStatement();
+			stmt.execute(sql);
+			stmt.close();
+			conn.close();
+		}
+
+
+		Assert.assertEquals(1, dataSource.getDataSourceStat().getSqlStatMap()
+				.size());
+		System.out.println(dataSource.getDataSourceStat().getSqlStatMap().keySet().iterator().next());
+		System.out.println("---------------------------------------------------");
+		System.out.println(SQLUtils.formatPGSql(sql));
+	}
+
+}
diff --git a/src/test/resources/bvt/parser/postgresql.txt b/src/test/resources/bvt/parser/postgresql.txt
new file mode 100644
index 0000000000..cc29107e67
--- /dev/null
+++ b/src/test/resources/bvt/parser/postgresql.txt
@@ -0,0 +1,19 @@
+/*!cobar: select,4,ireport.dm_mdm_mem_prod_effect_sdt0.admin_member_seq=201152175*/ 
+               select product_id, 
+                      sum_prod_show_num, 
+                      sum_prod_click_num, 
+                      sum_prod_fb_num, 
+                      total_cnt 
+                 from (select product_id, 
+                              sum_prod_show_num, 
+                              sum_prod_click_num, 
+                              sum_prod_fb_num, 
+                              count(*) over(order by a,b,c) as total_cnt 
+                         from (select product_id, 
+                                      sum_prod_show_num, 
+                                      sum_prod_click_num, 
+                                      sum_prod_fb_num 
+                                 from ireport.dm_mdm_mem_prod_effect_sdt0 
+                                where stat_date = '2012-02-19' 
+                                  and admin_member_seq = ?) b 
+                        Order by sum_prod_show_num desc, product_id desc) a limit ? offset (? -1) * ?