diff --git a/output/clickhouse_output.go b/output/clickhouse_output.go
index 4f2d910c..38a1631f 100644
--- a/output/clickhouse_output.go
+++ b/output/clickhouse_output.go
@@ -2,7 +2,6 @@ package output
 
 import (
 	"database/sql"
-	"encoding/json"
 	"fmt"
 	"math/rand"
 	"strings"
@@ -31,8 +30,6 @@ type ClickhouseOutput struct {
 
 	fieldsLength int
 	query        string
-	desc         map[string]*rowDesc
-	defaultValue map[string]interface{} // columnName -> defaultValue
 
 	bulkChan chan []map[string]interface{}
 
@@ -45,129 +42,6 @@ type ClickhouseOutput struct {
 	wg  sync.WaitGroup
 }
 
-type rowDesc struct {
-	Name              string `json:"name"`
-	Type              string `json:"type"`
-	DefaultType       string `json:"default_type"`
-	DefaultExpression string `json:"default_expression"`
-}
-
-func (c *ClickhouseOutput) setTableDesc() {
-	c.desc = make(map[string]*rowDesc)
-
-	query := fmt.Sprintf("desc table %s", c.table)
-	glog.V(5).Info(query)
-
-	for i := 0; i < c.dbSelector.Size(); i++ {
-		nextdb := c.dbSelector.Next()
-
-		db := nextdb.(*sql.DB)
-
-		rows, err := db.Query(query)
-		if err != nil {
-			glog.Errorf("query %q error: %s", query, err)
-			continue
-		}
-		defer rows.Close()
-
-		columns, err := rows.Columns()
-		if err != nil {
-			glog.Fatalf("could not get columns from query `%s`: %s", query, err)
-		}
-		glog.V(10).Infof("desc table columns: %v", columns)
-
-		descMap := make(map[string]string)
-		for _, c := range columns {
-			descMap[c] = ""
-		}
-
-		for rows.Next() {
-			values := make([]interface{}, 0)
-			for range columns {
-				var a string
-				values = append(values, &a)
-			}
-
-			if err := rows.Scan(values...); err != nil {
-				glog.Fatalf("scan rows error: %s", err)
-			}
-
-			descMap := make(map[string]string)
-			for i, c := range columns {
-				descMap[c] = *values[i].(*string)
-			}
-
-			b, err := json.Marshal(descMap)
-			if err != nil {
-				glog.Fatalf("marshal desc error: %s", err)
-			}
-
-			rowDesc := rowDesc{}
-			err = json.Unmarshal(b, &rowDesc)
-			if err != nil {
-				glog.Fatalf("marshal desc error: %s", err)
-			}
-
-			glog.V(5).Infof("row desc: %#v", rowDesc)
-
-			c.desc[rowDesc.Name] = &rowDesc
-		}
-
-		return
-	}
-}
-
-func (c *ClickhouseOutput) checkColumnDefault() {
-	fields := make(map[string]bool)
-	for _, f := range c.fields {
-		fields[f] = true
-	}
-
-	for column, d := range c.desc {
-		if _, ok := fields[column]; !ok {
-			continue
-		}
-
-		// TODO default expression should be supported
-		switch d.DefaultType {
-		case "MATERIALIZED", "ALIAS", "DEFAULT":
-			glog.Fatal("MATERIALIZED, ALIAS, DEFAULT field not supported")
-		}
-	}
-}
-
-func (c *ClickhouseOutput) setColumnDefault() {
-	c.setTableDesc()
-
-	c.defaultValue = make(map[string]interface{})
-
-	for columnName, d := range c.desc {
-		if d.DefaultType != "" {
-			c.defaultValue[columnName] = d.DefaultExpression
-			continue
-		}
-		switch d.Type {
-		case "String", "LowCardinality(String)":
-			c.defaultValue[columnName] = ""
-		case "Date", "DateTime":
-			c.defaultValue[columnName] = time.Unix(0, 0)
-		case "UInt8", "UInt16", "UInt32", "UInt64", "Int8", "Int16", "Int32", "Int64":
-			c.defaultValue[columnName] = 0
-		case "Float32", "Float64":
-			c.defaultValue[columnName] = 0.0
-		case "IPv4":
-			c.defaultValue[columnName] = "0.0.0.0"
-		case "IPv6":
-			c.defaultValue[columnName] = "::"
-		case "Array(String)":
-			c.defaultValue[columnName] = []string{}
-		default:
-			glog.Errorf("column: %s, type: %s. unsupported column type, ignore", columnName, d.Type)
-			continue
-		}
-	}
-}
-
 func (l *MethodLibrary) NewClickhouseOutput(config map[interface{}]interface{}) *ClickhouseOutput {
 	rand.Seed(time.Now().UnixNano())
 	p := &ClickhouseOutput{
@@ -254,9 +128,6 @@ func (l *MethodLibrary) NewClickhouseOutput(config map[interface{}]interface{})
 	}
 	p.dbSelector = NewRRHostSelector(dbsI, 3)
 
-	p.setColumnDefault()
-	p.checkColumnDefault()
-
 	concurrent := 1
 	if v, ok := config["concurrent"]; ok {
 		concurrent = v.(int)
@@ -332,15 +203,7 @@ func (p *ClickhouseOutput) innerFlush(events []map[string]interface{}) {
 		for _, event := range events {
 			args := make([]interface{}, p.fieldsLength)
 			for i, field := range p.fields {
-				if v, ok := event[field]; ok && v != nil {
-					args[i] = v
-				} else {
-					if vv, ok := p.defaultValue[field]; ok {
-						args[i] = vv
-					} else { // this should not happen
-						args[i] = ""
-					}
-				}
+				args[i] = event[field]
 			}
 			if _, err := stmt.Exec(args...); err != nil {
 				glog.Errorf("exec clickhouse insert %v error: %s", event, err)