diff --git a/src/infra/src/schema/mod.rs b/src/infra/src/schema/mod.rs
index 3b0645fbf2..b7e9fa97c7 100644
--- a/src/infra/src/schema/mod.rs
+++ b/src/infra/src/schema/mod.rs
@@ -352,6 +352,10 @@ pub async fn merge(
     schema: &Schema,
     min_ts: Option<i64>,
 ) -> Result<Option<(Schema, Vec<Field>)>> {
+    let stream_name = stream_name.trim();
+    if stream_name.is_empty() {
+        return Ok(None);
+    }
     let start_dt = min_ts;
     let key = mk_key(org_id, stream_type, stream_name);
     let inferred_schema = schema.clone();
@@ -465,6 +469,10 @@ pub async fn update_setting(
     stream_type: StreamType,
     metadata: std::collections::HashMap<String, String>,
 ) -> Result<()> {
+    let stream_name = stream_name.trim();
+    if stream_name.is_empty() {
+        return Ok(());
+    }
     let key = mk_key(org_id, stream_type, stream_name);
     let db = infra_db::get_db().await;
     db.get_for_update(
diff --git a/src/service/promql/search/grpc/wal.rs b/src/service/promql/search/grpc/wal.rs
index 9bfdb2eab5..c9e035ba4f 100644
--- a/src/service/promql/search/grpc/wal.rs
+++ b/src/service/promql/search/grpc/wal.rs
@@ -13,7 +13,10 @@
 // You should have received a copy of the GNU Affero General Public License
 // along with this program.  If not, see <http://www.gnu.org/licenses/>.
 
-use std::{collections::HashSet, sync::Arc};
+use std::{
+    collections::{HashMap, HashSet},
+    sync::Arc,
+};
 
 use arrow::record_batch::RecordBatch;
 use config::{
@@ -97,6 +100,7 @@ pub(crate) async fn create_context(
 
     let ctx = prepare_datafusion_context(None, vec![], false, 0).await?;
     let mem_table = Arc::new(MemTable::try_new(schema.clone(), vec![batches])?);
+    log::info!("[trace_id {trace_id}] promql->wal->search: register mem table done");
     ctx.register_table(stream_name, mem_table)?;
     resp.push((ctx, schema, stats));
 
@@ -189,9 +193,24 @@ async fn get_wal_batches(
         ret.map(|data| (data, visit.scan_stats, visit.partial_err))
     }?;
 
-    let mut schema = Arc::new(Schema::empty());
-    if !batches.is_empty() {
-        schema = Arc::clone(&batches[0].schema());
+    if batches.is_empty() {
+        return Ok((ScanStats::new(), vec![], Arc::new(Schema::empty())));
     }
-    Ok((stats, batches, schema))
+
+    // remove the metadata
+    let schema = Arc::new(
+        batches[0]
+            .schema()
+            .as_ref()
+            .clone()
+            .with_metadata(HashMap::new()),
+    );
+    let mut new_batches = Vec::with_capacity(batches.len());
+    for batch in batches {
+        new_batches.push(RecordBatch::try_new(
+            schema.clone(),
+            batch.columns().to_vec(),
+        )?);
+    }
+    Ok((stats, new_batches, schema))
 }