diff --git a/src/pipeline/src/etl.rs b/src/pipeline/src/etl.rs
index 1a75866656a6..b2c8802dd52a 100644
--- a/src/pipeline/src/etl.rs
+++ b/src/pipeline/src/etl.rs
@@ -284,7 +284,7 @@ where
                 let mut search_from = 0;
                 // because of the key in the json map is ordered
                 for (payload_key, payload_value) in map.into_iter() {
-                    if search_from >= self.required_keys.len() - 1 {
+                    if search_from >= self.required_keys.len() {
                         break;
                     }
 
@@ -359,15 +359,16 @@ mod tests {
 
     #[test]
     fn test_pipeline_prepare() {
-        let input_value_str = r#"
+        {
+            let input_value_str = r#"
             {
                 "my_field": "1,2",
                 "foo": "bar"
             }
         "#;
-        let input_value: serde_json::Value = serde_json::from_str(input_value_str).unwrap();
+            let input_value: serde_json::Value = serde_json::from_str(input_value_str).unwrap();
 
-        let pipeline_yaml = r#"
+            let pipeline_yaml = r#"
 ---
 description: Pipeline for Apache Tomcat
 
@@ -381,32 +382,73 @@ transform:
   - field: field2
     type: uint32
 "#;
-        let pipeline: Pipeline<GreptimeTransformer> =
-            parse(&Content::Yaml(pipeline_yaml.into())).unwrap();
-        let mut payload = pipeline.init_intermediate_state();
-        pipeline.prepare(input_value, &mut payload).unwrap();
-        assert_eq!(
-            &["greptime_timestamp", "my_field"].to_vec(),
-            pipeline.required_keys()
-        );
-        assert_eq!(
-            payload,
-            vec![
-                Value::Null,
-                Value::String("1,2".to_string()),
-                Value::Null,
-                Value::Null
-            ]
-        );
-        let result = pipeline.exec_mut(&mut payload).unwrap();
+            let pipeline: Pipeline<GreptimeTransformer> =
+                parse(&Content::Yaml(pipeline_yaml.into())).unwrap();
+            let mut payload = pipeline.init_intermediate_state();
+            pipeline.prepare(input_value, &mut payload).unwrap();
+            assert_eq!(
+                &["greptime_timestamp", "my_field"].to_vec(),
+                pipeline.required_keys()
+            );
+            assert_eq!(
+                payload,
+                vec![
+                    Value::Null,
+                    Value::String("1,2".to_string()),
+                    Value::Null,
+                    Value::Null
+                ]
+            );
+            let result = pipeline.exec_mut(&mut payload).unwrap();
 
-        assert_eq!(result.values[0].value_data, Some(ValueData::U32Value(1)));
-        assert_eq!(result.values[1].value_data, Some(ValueData::U32Value(2)));
-        match &result.values[2].value_data {
-            Some(ValueData::TimestampNanosecondValue(v)) => {
-                assert_ne!(*v, 0);
+            assert_eq!(result.values[0].value_data, Some(ValueData::U32Value(1)));
+            assert_eq!(result.values[1].value_data, Some(ValueData::U32Value(2)));
+            match &result.values[2].value_data {
+                Some(ValueData::TimestampNanosecondValue(v)) => {
+                    assert_ne!(*v, 0);
+                }
+                _ => panic!("expect null value"),
             }
-            _ => panic!("expect null value"),
+        }
+        {
+            let input_value_str = r#"
+          {
+            "reqTimeSec": "1573840000.000"
+          }
+    "#;
+
+            let pipeline_yaml = r#"
+---
+description: Pipeline for Demo Log
+
+processors:
+  - gsub:
+      field: reqTimeSec
+      pattern: "\\."
+      replacement: ""
+  - epoch:
+      field: reqTimeSec
+      resolution: millisecond
+      ignore_missing: true
+
+transform:
+  - field: reqTimeSec
+    type: epoch, millisecond
+    index: timestamp
+"#;
+            let input_value: serde_json::Value = serde_json::from_str(input_value_str).unwrap();
+            let pipeline: Pipeline<GreptimeTransformer> =
+                parse(&Content::Yaml(pipeline_yaml.into())).unwrap();
+            let mut payload = pipeline.init_intermediate_state();
+            pipeline.prepare(input_value, &mut payload).unwrap();
+            assert_eq!(&["reqTimeSec"].to_vec(), pipeline.required_keys());
+            assert_eq!(payload, vec![Value::String("1573840000.000".to_string())]);
+            let result = pipeline.exec_mut(&mut payload).unwrap();
+
+            assert_eq!(
+                result.values[0].value_data,
+                Some(ValueData::TimestampMillisecondValue(1573840000000))
+            );
         }
     }