diff --git a/src/servers/src/influxdb.rs b/src/servers/src/influxdb.rs
index 9ce78be2632c..870573679370 100644
--- a/src/servers/src/influxdb.rs
+++ b/src/servers/src/influxdb.rs
@@ -53,7 +53,7 @@ impl TryFrom<InfluxdbRequest> for RowInsertRequests {
 
             // tags
             if let Some(tags) = tags {
-                let kvs = tags.iter().map(|(k, v)| (k.to_string(), v.as_str()));
+                let kvs = tags.iter().map(|(k, v)| (k.to_string(), v.to_string()));
                 row_writer::write_tags(table_data, kvs, &mut one_row)?;
             }
 
diff --git a/src/servers/src/prom_store.rs b/src/servers/src/prom_store.rs
index 3c114f335d13..d4017cd4e107 100644
--- a/src/servers/src/prom_store.rs
+++ b/src/servers/src/prom_store.rs
@@ -303,7 +303,7 @@ pub fn to_grpc_row_insert_requests(request: WriteRequest) -> Result<(RowInsertRe
 
     let mut multi_table_data = MultiTableData::new();
 
-    for series in &request.timeseries {
+    for series in request.timeseries {
         let table_name = &series
             .labels
             .iter()
@@ -326,29 +326,54 @@ pub fn to_grpc_row_insert_requests(request: WriteRequest) -> Result<(RowInsertRe
             series.samples.len(),
         );
 
-        for Sample { value, timestamp } in &series.samples {
+        // labels
+        let kvs = series.labels.into_iter().filter_map(|label| {
+            if label.name == METRIC_NAME_LABEL {
+                None
+            } else {
+                Some((label.name, label.value))
+            }
+        });
+
+        if series.samples.len() == 1 {
             let mut one_row = table_data.alloc_one_row();
 
-            // labels
-            let kvs = series.labels.iter().filter_map(|label| {
-                if label.name == METRIC_NAME_LABEL {
-                    None
-                } else {
-                    Some((label.name.to_string(), label.value.as_str()))
-                }
-            });
             row_writer::write_tags(table_data, kvs, &mut one_row)?;
             // value
-            row_writer::write_f64(table_data, GREPTIME_VALUE, *value, &mut one_row)?;
+            row_writer::write_f64(
+                table_data,
+                GREPTIME_VALUE,
+                series.samples[0].value,
+                &mut one_row,
+            )?;
             // timestamp
             row_writer::write_ts_millis(
                 table_data,
                 GREPTIME_TIMESTAMP,
-                Some(*timestamp),
+                Some(series.samples[0].timestamp),
                 &mut one_row,
             )?;
 
             table_data.add_row(one_row);
+        } else {
+            for Sample { value, timestamp } in &series.samples {
+                let mut one_row = table_data.alloc_one_row();
+
+                // labels
+                let kvs = kvs.clone();
+                row_writer::write_tags(table_data, kvs, &mut one_row)?;
+                // value
+                row_writer::write_f64(table_data, GREPTIME_VALUE, *value, &mut one_row)?;
+                // timestamp
+                row_writer::write_ts_millis(
+                    table_data,
+                    GREPTIME_TIMESTAMP,
+                    Some(*timestamp),
+                    &mut one_row,
+                )?;
+
+                table_data.add_row(one_row);
+            }
         }
     }
 
diff --git a/src/servers/src/row_writer.rs b/src/servers/src/row_writer.rs
index c11f3bfc9fc8..4b8956015ef1 100644
--- a/src/servers/src/row_writer.rs
+++ b/src/servers/src/row_writer.rs
@@ -140,16 +140,10 @@ impl MultiTableData {
 
 pub fn write_tags(
     table_data: &mut TableData,
-    kvs: impl Iterator<Item = (String, impl ToString)>,
+    kvs: impl Iterator<Item = (String, String)>,
     one_row: &mut Vec<Value>,
 ) -> Result<()> {
-    let ktv_iter = kvs.map(|(k, v)| {
-        (
-            k,
-            ColumnDataType::String,
-            ValueData::StringValue(v.to_string()),
-        )
-    });
+    let ktv_iter = kvs.map(|(k, v)| (k, ColumnDataType::String, ValueData::StringValue(v)));
     write_by_semantic_type(table_data, SemanticType::Tag, ktv_iter, one_row)
 }
 
@@ -209,18 +203,22 @@ fn write_by_semantic_type(
     } = table_data;
 
     for (name, datatype, value) in ktv_iter {
-        let index = column_indexes.entry(name.clone()).or_insert(schema.len());
-        if *index == schema.len() {
+        let index = column_indexes.get(&name);
+        if let Some(index) = index {
+            check_schema(datatype, semantic_type, &schema[*index])?;
+            one_row[*index].value_data = Some(value);
+        } else {
+            let index = schema.len();
             schema.push(ColumnSchema {
-                column_name: name,
+                column_name: name.clone(),
                 datatype: datatype as i32,
                 semantic_type: semantic_type as i32,
                 ..Default::default()
             });
-            one_row.push(value.into());
-        } else {
-            check_schema(datatype, semantic_type, &schema[*index])?;
-            one_row[*index].value_data = Some(value);
+            column_indexes.insert(name, index);
+            one_row.push(Value {
+                value_data: Some(value),
+            });
         }
     }
 
@@ -264,22 +262,24 @@ pub fn write_ts_precision(
         }
     };
 
-    let index = column_indexes.entry(name.clone()).or_insert(schema.len());
-    if *index == schema.len() {
-        schema.push(ColumnSchema {
-            column_name: name,
-            datatype: ColumnDataType::TimestampMillisecond as i32,
-            semantic_type: SemanticType::Timestamp as i32,
-            ..Default::default()
-        });
-        one_row.push(ValueData::TimestampMillisecondValue(ts).into())
-    } else {
+    let index = column_indexes.get(&name);
+    if let Some(index) = index {
         check_schema(
             ColumnDataType::TimestampMillisecond,
             SemanticType::Timestamp,
             &schema[*index],
         )?;
         one_row[*index].value_data = Some(ValueData::TimestampMillisecondValue(ts));
+    } else {
+        let index = schema.len();
+        schema.push(ColumnSchema {
+            column_name: name.clone(),
+            datatype: ColumnDataType::TimestampMillisecond as i32,
+            semantic_type: SemanticType::Timestamp as i32,
+            ..Default::default()
+        });
+        column_indexes.insert(name, index);
+        one_row.push(ValueData::TimestampMillisecondValue(ts).into())
     }
 
     Ok(())