diff --git a/src/pipeline/src/etl/transform.rs b/src/pipeline/src/etl/transform.rs
index 14cfa440fb..27afeaa7de 100644
--- a/src/pipeline/src/etl/transform.rs
+++ b/src/pipeline/src/etl/transform.rs
@@ -18,6 +18,7 @@ pub mod transformer;
 use snafu::OptionExt;
 
 use crate::etl::error::{Error, Result};
+use crate::etl::processor::yaml_bool;
 use crate::etl::transform::index::Index;
 use crate::etl::value::Value;
 
@@ -25,6 +26,7 @@ const TRANSFORM_FIELD: &str = "field";
 const TRANSFORM_FIELDS: &str = "fields";
 const TRANSFORM_TYPE: &str = "type";
 const TRANSFORM_INDEX: &str = "index";
+const TRANSFORM_TAG: &str = "tag";
 const TRANSFORM_DEFAULT: &str = "default";
 const TRANSFORM_ON_FAILURE: &str = "on_failure";
 
@@ -144,6 +146,8 @@ pub struct Transform {
 
     pub index: Option<Index>,
 
+    pub tag: bool,
+
     pub on_failure: Option<OnFailure>,
 }
 
@@ -154,6 +158,7 @@ impl Default for Transform {
             type_: Value::Null,
             default: None,
             index: None,
+            tag: false,
             on_failure: None,
         }
     }
@@ -185,6 +190,7 @@ impl TryFrom<&yaml_rust::yaml::Hash> for Transform {
         let mut type_ = Value::Null;
         let mut default = None;
         let mut index = None;
+        let mut tag = false;
         let mut on_failure = None;
 
         for (k, v) in hash {
@@ -210,6 +216,10 @@ impl TryFrom<&yaml_rust::yaml::Hash> for Transform {
                     index = Some(index_str.try_into()?);
                 }
 
+                TRANSFORM_TAG => {
+                    tag = yaml_bool(v, TRANSFORM_TAG)?;
+                }
+
                 TRANSFORM_DEFAULT => {
                     default = Some(Value::try_from(v)?);
                 }
@@ -247,6 +257,7 @@ impl TryFrom<&yaml_rust::yaml::Hash> for Transform {
             default: final_default,
             index,
             on_failure,
+            tag,
         };
 
         Ok(builder)
diff --git a/src/pipeline/src/etl/transform/transformer/greptime.rs b/src/pipeline/src/etl/transform/transformer/greptime.rs
index 0211e67db1..7b4dab958a 100644
--- a/src/pipeline/src/etl/transform/transformer/greptime.rs
+++ b/src/pipeline/src/etl/transform/transformer/greptime.rs
@@ -96,6 +96,7 @@ impl GreptimeTransformer {
             default,
             index: Some(Index::Time),
             on_failure: Some(crate::etl::transform::OnFailure::Default),
+            tag: false,
         };
         transforms.push(transform);
     }
diff --git a/src/pipeline/src/etl/transform/transformer/greptime/coerce.rs b/src/pipeline/src/etl/transform/transformer/greptime/coerce.rs
index e6e315e175..97cefe48ff 100644
--- a/src/pipeline/src/etl/transform/transformer/greptime/coerce.rs
+++ b/src/pipeline/src/etl/transform/transformer/greptime/coerce.rs
@@ -95,6 +95,10 @@ pub(crate) fn coerce_columns(transform: &Transform) -> Result<Vec<ColumnSchema>>
 }
 
 fn coerce_semantic_type(transform: &Transform) -> SemanticType {
+    if transform.tag {
+        return SemanticType::Tag;
+    }
+
     match transform.index {
         Some(Index::Tag) => SemanticType::Tag,
         Some(Index::Time) => SemanticType::Timestamp,
@@ -478,6 +482,7 @@ mod tests {
             default: None,
             index: None,
             on_failure: None,
+            tag: false,
         };
 
         // valid string
@@ -503,6 +508,7 @@ mod tests {
             default: None,
             index: None,
             on_failure: Some(OnFailure::Ignore),
+            tag: false,
         };
 
         let val = Value::String("hello".to_string());
@@ -518,6 +524,7 @@ mod tests {
             default: None,
             index: None,
             on_failure: Some(OnFailure::Default),
+            tag: false,
         };
 
         // with no explicit default value
diff --git a/tests-integration/tests/http.rs b/tests-integration/tests/http.rs
index c6fd59a631..154034dd67 100644
--- a/tests-integration/tests/http.rs
+++ b/tests-integration/tests/http.rs
@@ -1271,9 +1271,11 @@ transform:
   - field: type
     type: string
     index: skipping
+    tag: true
   - field: log
     type: string
     index: fulltext
+    tag: true
   - field: time
     type: time
     index: timestamp
@@ -1349,7 +1351,7 @@ transform:
 
     // 3. check schema
 
-    let expected_schema =  "[[\"logs1\",\"CREATE TABLE IF NOT EXISTS \\\"logs1\\\" (\\n  \\\"id1\\\" INT NULL,\\n  \\\"id2\\\" INT NULL,\\n  \\\"logger\\\" STRING NULL,\\n  \\\"type\\\" STRING NULL SKIPPING INDEX WITH(granularity = '10240', type = 'BLOOM'),\\n  \\\"log\\\" STRING NULL FULLTEXT INDEX WITH(analyzer = 'English', case_sensitive = 'false'),\\n  \\\"time\\\" TIMESTAMP(9) NOT NULL,\\n  TIME INDEX (\\\"time\\\")\\n)\\n\\nENGINE=mito\\nWITH(\\n  append_mode = 'true'\\n)\"]]";
+    let expected_schema =   "[[\"logs1\",\"CREATE TABLE IF NOT EXISTS \\\"logs1\\\" (\\n  \\\"id1\\\" INT NULL,\\n  \\\"id2\\\" INT NULL,\\n  \\\"logger\\\" STRING NULL,\\n  \\\"type\\\" STRING NULL SKIPPING INDEX WITH(granularity = '10240', type = 'BLOOM'),\\n  \\\"log\\\" STRING NULL FULLTEXT INDEX WITH(analyzer = 'English', case_sensitive = 'false'),\\n  \\\"time\\\" TIMESTAMP(9) NOT NULL,\\n  TIME INDEX (\\\"time\\\"),\\n  PRIMARY KEY (\\\"type\\\", \\\"log\\\")\\n)\\n\\nENGINE=mito\\nWITH(\\n  append_mode = 'true'\\n)\"]]";
     validate_data(
         "pipeline_schema",
         &client,