From 32d2c64de7acd0ea5a9345879168c99a7996218a Mon Sep 17 00:00:00 2001
From: evenyag <realevenyag@gmail.com>
Date: Wed, 7 Jan 2026 22:12:09 +0800
Subject: [PATCH 01/10] fix: show convert cost in explain analyze verbose

Signed-off-by: evenyag <realevenyag@gmail.com>
---
 src/mito2/src/read/scan_util.rs | 33 +++++++++++++++++++++++++++------
 1 file changed, 27 insertions(+), 6 deletions(-)

diff --git a/src/mito2/src/read/scan_util.rs b/src/mito2/src/read/scan_util.rs
index 0605c3709675..8aa139e69fe1 100644
--- a/src/mito2/src/read/scan_util.rs
+++ b/src/mito2/src/read/scan_util.rs
@@ -115,6 +115,8 @@ pub(crate) struct ScanMetricsSet {
     scan_cost: Duration,
     /// Duration while waiting for `yield`.
     yield_cost: Duration,
+    /// Duration to convert [`Batch`]es.
+    convert_cost: Option<Time>,
     /// Duration of the scan.
     total_cost: Duration,
     /// Number of rows returned.
@@ -243,6 +245,7 @@ impl fmt::Debug for ScanMetricsSet {
             build_reader_cost,
             scan_cost,
             yield_cost,
+            convert_cost,
             total_cost,
             num_rows,
             num_batches,
@@ -307,6 +310,12 @@ impl fmt::Debug for ScanMetricsSet {
             \"first_poll\":\"{first_poll:?}\""
         )?;
 
+        // Write convert_cost if present
+        if let Some(time) = convert_cost {
+            let duration = Duration::from_nanos(time.value() as u64);
+            write!(f, ", \"convert_cost\":\"{duration:?}\"")?;
+        }
+
         // Write non-zero filter counters
         if *rg_fulltext_filtered > 0 {
             write!(f, ", \"rg_fulltext_filtered\":{rg_fulltext_filtered}")?;
@@ -466,6 +475,12 @@ impl ScanMetricsSet {
         self
     }
 
+    /// Attaches the `convert_cost` to the metrics set.
+    fn with_convert_cost(mut self, time: Time) -> Self {
+        self.convert_cost = Some(time);
+        self
+    }
+
     /// Merges the local scanner metrics.
     fn merge_scanner_metrics(&mut self, other: &ScannerMetrics) {
         let ScannerMetrics {
@@ -606,6 +621,11 @@ impl ScanMetricsSet {
         READ_STAGE_ELAPSED
             .with_label_values(&["yield"])
             .observe(self.yield_cost.as_secs_f64());
+        if let Some(time) = &self.convert_cost {
+            READ_STAGE_ELAPSED
+                .with_label_values(&["convert"])
+                .observe(Duration::from_nanos(time.value() as u64).as_secs_f64());
+        }
         READ_STAGE_ELAPSED
             .with_label_values(&["total"])
             .observe(self.total_cost.as_secs_f64());
@@ -722,21 +742,19 @@ impl Drop for PartitionMetricsInner {
 
         if self.explain_verbose {
             common_telemetry::info!(
-                "{} finished, region_id: {}, partition: {}, scan_metrics: {:?}, convert_batch_costs: {}",
+                "{} finished, region_id: {}, partition: {}, scan_metrics: {:?}",
                 self.scanner_type,
                 self.region_id,
                 self.partition,
                 metrics,
-                self.convert_cost,
             );
         } else {
             common_telemetry::debug!(
-                "{} finished, region_id: {}, partition: {}, scan_metrics: {:?}, convert_batch_costs: {}",
+                "{} finished, region_id: {}, partition: {}, scan_metrics: {:?}",
                 self.scanner_type,
                 self.region_id,
                 self.partition,
                 metrics,
-                self.convert_cost,
             );
         }
     }
@@ -783,7 +801,10 @@ impl PartitionMetrics {
         let partition_str = partition.to_string();
         let in_progress_scan = IN_PROGRESS_SCAN.with_label_values(&[scanner_type, &partition_str]);
         in_progress_scan.inc();
-        let metrics = ScanMetricsSet::default().with_prepare_scan_cost(query_start.elapsed());
+        let convert_cost = MetricBuilder::new(metrics_set).subset_time("convert_cost", partition);
+        let metrics = ScanMetricsSet::default()
+            .with_prepare_scan_cost(query_start.elapsed())
+            .with_convert_cost(convert_cost.clone());
         let inner = PartitionMetricsInner {
             region_id,
             partition,
@@ -798,7 +819,7 @@ impl PartitionMetrics {
                 .subset_time("build_reader_cost", partition),
             scan_cost: MetricBuilder::new(metrics_set).subset_time("scan_cost", partition),
             yield_cost: MetricBuilder::new(metrics_set).subset_time("yield_cost", partition),
-            convert_cost: MetricBuilder::new(metrics_set).subset_time("convert_cost", partition),
+            convert_cost,
             elapsed_compute: MetricBuilder::new(metrics_set).elapsed_compute(partition),
         };
         Self(Arc::new(inner))

From 426a7be63f67ca33ebfd5a552199fda4b5ede008 Mon Sep 17 00:00:00 2001
From: evenyag <realevenyag@gmail.com>
Date: Wed, 7 Jan 2026 22:58:03 +0800
Subject: [PATCH 02/10] fix: increase puffin metadata cache metric

Signed-off-by: evenyag <realevenyag@gmail.com>
---
 src/puffin/src/puffin_manager/cache.rs | 8 +++++++-
 1 file changed, 7 insertions(+), 1 deletion(-)

diff --git a/src/puffin/src/puffin_manager/cache.rs b/src/puffin/src/puffin_manager/cache.rs
index c2c5fb67f496..fc6df95d0270 100644
--- a/src/puffin/src/puffin_manager/cache.rs
+++ b/src/puffin/src/puffin_manager/cache.rs
@@ -25,6 +25,7 @@ pub type PuffinMetadataCacheRef = Arc<PuffinMetadataCache>;
 /// A cache for storing the metadata of the index files.
 pub struct PuffinMetadataCache {
     cache: moka::sync::Cache<String, Arc<FileMetadata>>,
+    cache_bytes: IntGaugeVec,
 }
 
 fn puffin_metadata_weight(k: &str, v: &Arc<FileMetadata>) -> u32 {
@@ -38,13 +39,14 @@ impl PuffinMetadataCache {
             cache: moka::sync::CacheBuilder::new(capacity)
                 .name("puffin_metadata")
                 .weigher(|k: &String, v| puffin_metadata_weight(k, v))
-                .eviction_listener(|k, v, _cause| {
+                .eviction_listener(move |k, v, _cause| {
                     let size = puffin_metadata_weight(&k, &v);
                     cache_bytes
                         .with_label_values(&[PUFFIN_METADATA_TYPE])
                         .sub(size.into());
                 })
                 .build(),
+            cache_bytes: cache_bytes.clone(),
         }
     }
 
@@ -55,6 +57,10 @@ impl PuffinMetadataCache {
 
     /// Puts the metadata into the cache.
     pub fn put_metadata(&self, file_id: String, metadata: Arc<FileMetadata>) {
+        let size = puffin_metadata_weight(&file_id, &metadata);
+        self.cache_bytes
+            .with_label_values(&[PUFFIN_METADATA_TYPE])
+            .add(size.into());
         self.cache.insert(file_id, metadata);
     }
 

From 40fd32c624485bf08682c270c9d8be937c020053 Mon Sep 17 00:00:00 2001
From: evenyag <realevenyag@gmail.com>
Date: Wed, 7 Jan 2026 23:35:49 +0800
Subject: [PATCH 03/10] feat: add result cache hit/miss to filter metrics

Signed-off-by: evenyag <realevenyag@gmail.com>
---
 src/mito2/src/read/scan_util.rs     | 61 +++++++++++++++++++++++++++++
 src/mito2/src/sst/parquet/reader.rs | 28 +++++++++++++
 2 files changed, 89 insertions(+)

diff --git a/src/mito2/src/read/scan_util.rs b/src/mito2/src/read/scan_util.rs
index 8aa139e69fe1..1ffd34de2f21 100644
--- a/src/mito2/src/read/scan_util.rs
+++ b/src/mito2/src/read/scan_util.rs
@@ -163,6 +163,18 @@ pub(crate) struct ScanMetricsSet {
     rows_bloom_filtered: usize,
     /// Number of rows filtered by precise filter.
     rows_precise_filtered: usize,
+    /// Number of index result cache hits for fulltext index.
+    fulltext_index_cache_hit: usize,
+    /// Number of index result cache misses for fulltext index.
+    fulltext_index_cache_miss: usize,
+    /// Number of index result cache hits for inverted index.
+    inverted_index_cache_hit: usize,
+    /// Number of index result cache misses for inverted index.
+    inverted_index_cache_miss: usize,
+    /// Number of index result cache hits for bloom filter index.
+    bloom_filter_cache_hit: usize,
+    /// Number of index result cache misses for bloom filter index.
+    bloom_filter_cache_miss: usize,
     /// Number of record batches read from SST.
     num_sst_record_batches: usize,
     /// Number of batches decoded from SST.
@@ -263,6 +275,12 @@ impl fmt::Debug for ScanMetricsSet {
             rows_inverted_filtered,
             rows_bloom_filtered,
             rows_precise_filtered,
+            fulltext_index_cache_hit,
+            fulltext_index_cache_miss,
+            inverted_index_cache_hit,
+            inverted_index_cache_miss,
+            bloom_filter_cache_hit,
+            bloom_filter_cache_miss,
             num_sst_record_batches,
             num_sst_batches,
             num_sst_rows,
@@ -341,6 +359,36 @@ impl fmt::Debug for ScanMetricsSet {
         if *rows_precise_filtered > 0 {
             write!(f, ", \"rows_precise_filtered\":{rows_precise_filtered}")?;
         }
+        if *fulltext_index_cache_hit > 0 {
+            write!(
+                f,
+                ", \"fulltext_index_cache_hit\":{fulltext_index_cache_hit}"
+            )?;
+        }
+        if *fulltext_index_cache_miss > 0 {
+            write!(
+                f,
+                ", \"fulltext_index_cache_miss\":{fulltext_index_cache_miss}"
+            )?;
+        }
+        if *inverted_index_cache_hit > 0 {
+            write!(
+                f,
+                ", \"inverted_index_cache_hit\":{inverted_index_cache_hit}"
+            )?;
+        }
+        if *inverted_index_cache_miss > 0 {
+            write!(
+                f,
+                ", \"inverted_index_cache_miss\":{inverted_index_cache_miss}"
+            )?;
+        }
+        if *bloom_filter_cache_hit > 0 {
+            write!(f, ", \"bloom_filter_cache_hit\":{bloom_filter_cache_hit}")?;
+        }
+        if *bloom_filter_cache_miss > 0 {
+            write!(f, ", \"bloom_filter_cache_miss\":{bloom_filter_cache_miss}")?;
+        }
 
         // Write non-zero distributor metrics
         if *num_series_send_timeout > 0 {
@@ -520,6 +568,12 @@ impl ScanMetricsSet {
                     rows_inverted_filtered,
                     rows_bloom_filtered,
                     rows_precise_filtered,
+                    fulltext_index_cache_hit,
+                    fulltext_index_cache_miss,
+                    inverted_index_cache_hit,
+                    inverted_index_cache_miss,
+                    bloom_filter_cache_hit,
+                    bloom_filter_cache_miss,
                     inverted_index_apply_metrics,
                     bloom_filter_apply_metrics,
                     fulltext_index_apply_metrics,
@@ -547,6 +601,13 @@ impl ScanMetricsSet {
         self.rows_bloom_filtered += *rows_bloom_filtered;
         self.rows_precise_filtered += *rows_precise_filtered;
 
+        self.fulltext_index_cache_hit += *fulltext_index_cache_hit;
+        self.fulltext_index_cache_miss += *fulltext_index_cache_miss;
+        self.inverted_index_cache_hit += *inverted_index_cache_hit;
+        self.inverted_index_cache_miss += *inverted_index_cache_miss;
+        self.bloom_filter_cache_hit += *bloom_filter_cache_hit;
+        self.bloom_filter_cache_miss += *bloom_filter_cache_miss;
+
         self.num_sst_record_batches += *num_record_batches;
         self.num_sst_batches += *num_batches;
         self.num_sst_rows += *num_rows;
diff --git a/src/mito2/src/sst/parquet/reader.rs b/src/mito2/src/sst/parquet/reader.rs
index 0484892b21e6..6a0e5395a792 100644
--- a/src/mito2/src/sst/parquet/reader.rs
+++ b/src/mito2/src/sst/parquet/reader.rs
@@ -606,11 +606,13 @@ impl ParquetReaderBuilder {
                 && all_required_row_groups_searched(output, result)
             {
                 apply_selection_and_update_metrics(output, result, metrics, INDEX_TYPE_FULLTEXT);
+                metrics.fulltext_index_cache_hit += 1;
                 pruned = true;
                 continue;
             }
 
             // Slow path: apply the index from the file.
+            metrics.fulltext_index_cache_miss += 1;
             let file_size_hint = self.file_handle.meta_ref().index_file_size();
             let apply_res = index_applier
                 .apply_fine(
@@ -678,11 +680,13 @@ impl ParquetReaderBuilder {
                 && all_required_row_groups_searched(output, result)
             {
                 apply_selection_and_update_metrics(output, result, metrics, INDEX_TYPE_INVERTED);
+                metrics.inverted_index_cache_hit += 1;
                 pruned = true;
                 continue;
             }
 
             // Slow path: apply the index from the file.
+            metrics.inverted_index_cache_miss += 1;
             let file_size_hint = self.file_handle.meta_ref().index_file_size();
             let apply_res = index_applier
                 .apply(
@@ -746,11 +750,13 @@ impl ParquetReaderBuilder {
                 && all_required_row_groups_searched(output, result)
             {
                 apply_selection_and_update_metrics(output, result, metrics, INDEX_TYPE_BLOOM);
+                metrics.bloom_filter_cache_hit += 1;
                 pruned = true;
                 continue;
             }
 
             // Slow path: apply the index from the file.
+            metrics.bloom_filter_cache_miss += 1;
             let file_size_hint = self.file_handle.meta_ref().index_file_size();
             let rgs = parquet_meta.row_groups().iter().enumerate().map(|(i, rg)| {
                 (
@@ -829,11 +835,13 @@ impl ParquetReaderBuilder {
                 && all_required_row_groups_searched(output, result)
             {
                 apply_selection_and_update_metrics(output, result, metrics, INDEX_TYPE_FULLTEXT);
+                metrics.fulltext_index_cache_hit += 1;
                 pruned = true;
                 continue;
             }
 
             // Slow path: apply the index from the file.
+            metrics.fulltext_index_cache_miss += 1;
             let file_size_hint = self.file_handle.meta_ref().index_file_size();
             let rgs = parquet_meta.row_groups().iter().enumerate().map(|(i, rg)| {
                 (
@@ -1020,6 +1028,19 @@ pub(crate) struct ReaderFilterMetrics {
     /// Number of rows filtered by precise filter.
     pub(crate) rows_precise_filtered: usize,
 
+    /// Number of index result cache hits for fulltext index.
+    pub(crate) fulltext_index_cache_hit: usize,
+    /// Number of index result cache misses for fulltext index.
+    pub(crate) fulltext_index_cache_miss: usize,
+    /// Number of index result cache hits for inverted index.
+    pub(crate) inverted_index_cache_hit: usize,
+    /// Number of index result cache misses for inverted index.
+    pub(crate) inverted_index_cache_miss: usize,
+    /// Number of index result cache hits for bloom filter index.
+    pub(crate) bloom_filter_cache_hit: usize,
+    /// Number of index result cache misses for bloom filter index.
+    pub(crate) bloom_filter_cache_miss: usize,
+
     /// Optional metrics for inverted index applier.
     pub(crate) inverted_index_apply_metrics: Option<InvertedIndexApplyMetrics>,
     /// Optional metrics for bloom filter index applier.
@@ -1043,6 +1064,13 @@ impl ReaderFilterMetrics {
         self.rows_bloom_filtered += other.rows_bloom_filtered;
         self.rows_precise_filtered += other.rows_precise_filtered;
 
+        self.fulltext_index_cache_hit += other.fulltext_index_cache_hit;
+        self.fulltext_index_cache_miss += other.fulltext_index_cache_miss;
+        self.inverted_index_cache_hit += other.inverted_index_cache_hit;
+        self.inverted_index_cache_miss += other.inverted_index_cache_miss;
+        self.bloom_filter_cache_hit += other.bloom_filter_cache_hit;
+        self.bloom_filter_cache_miss += other.bloom_filter_cache_miss;
+
         // Merge optional applier metrics
         if let Some(other_metrics) = &other.inverted_index_apply_metrics {
             self.inverted_index_apply_metrics

From a5aae4b9502f76976b9390ed50330e48a69437aa Mon Sep 17 00:00:00 2001
From: evenyag <realevenyag@gmail.com>
Date: Thu, 8 Jan 2026 00:00:23 +0800
Subject: [PATCH 04/10] feat: print flat format in debug

Signed-off-by: evenyag <realevenyag@gmail.com>
---
 src/mito2/src/read/scan_region.rs | 1 +
 1 file changed, 1 insertion(+)

diff --git a/src/mito2/src/read/scan_region.rs b/src/mito2/src/read/scan_region.rs
index f6d39ee9015c..6fbc7deb7644 100644
--- a/src/mito2/src/read/scan_region.rs
+++ b/src/mito2/src/read/scan_region.rs
@@ -1418,6 +1418,7 @@ impl StreamContext {
                         .entries(self.input.files.iter().map(|file| FileWrapper { file }))
                         .finish()?;
                 }
+                write!(f, ", \"flat_format\": {}", self.input.flat_format)?;
 
                 #[cfg(feature = "enterprise")]
                 self.format_extension_ranges(f)?;

From 866c0ca7fcb17fa1047d9fd59567612c02810147 Mon Sep 17 00:00:00 2001
From: evenyag <realevenyag@gmail.com>
Date: Thu, 8 Jan 2026 15:53:31 +0800
Subject: [PATCH 05/10] test: update sqlness test

Signed-off-by: evenyag <realevenyag@gmail.com>
---
 tests/cases/distributed/tql-explain-analyze/analyze.result | 1 +
 tests/cases/distributed/tql-explain-analyze/analyze.sql    | 1 +
 tests/cases/standalone/common/promql/regex.result          | 4 ++++
 tests/cases/standalone/common/promql/regex.sql             | 4 ++++
 tests/cases/standalone/tql-explain-analyze/analyze.result  | 2 ++
 tests/cases/standalone/tql-explain-analyze/analyze.sql     | 2 ++
 6 files changed, 14 insertions(+)

diff --git a/tests/cases/distributed/tql-explain-analyze/analyze.result b/tests/cases/distributed/tql-explain-analyze/analyze.result
index ac40094d99af..471f1eeaf208 100644
--- a/tests/cases/distributed/tql-explain-analyze/analyze.result
+++ b/tests/cases/distributed/tql-explain-analyze/analyze.result
@@ -90,6 +90,7 @@ TQL ANALYZE ('1970-01-01T00:00:00'::timestamp, '1970-01-01T00:00:00'::timestamp
 -- SQLNESS REPLACE (Duration.*) REDACTED
 -- SQLNESS REPLACE region=\d+\(\d+,\s+\d+\) region=REDACTED
 -- SQLNESS REPLACE (Hash.*) REDACTED
+-- SQLNESS REPLACE (flat_format.*) REDACTED
 TQL ANALYZE VERBOSE (0, 10, '5s') test;
 
 +-+-+-+
diff --git a/tests/cases/distributed/tql-explain-analyze/analyze.sql b/tests/cases/distributed/tql-explain-analyze/analyze.sql
index f9438781d88c..e8bdf92838ac 100644
--- a/tests/cases/distributed/tql-explain-analyze/analyze.sql
+++ b/tests/cases/distributed/tql-explain-analyze/analyze.sql
@@ -44,6 +44,7 @@ TQL ANALYZE ('1970-01-01T00:00:00'::timestamp, '1970-01-01T00:00:00'::timestamp
 -- SQLNESS REPLACE (Duration.*) REDACTED
 -- SQLNESS REPLACE region=\d+\(\d+,\s+\d+\) region=REDACTED
 -- SQLNESS REPLACE (Hash.*) REDACTED
+-- SQLNESS REPLACE (flat_format.*) REDACTED
 TQL ANALYZE VERBOSE (0, 10, '5s') test;
 
 DROP TABLE test;
diff --git a/tests/cases/standalone/common/promql/regex.result b/tests/cases/standalone/common/promql/regex.result
index ab71cf8e7a40..ed89c720c26d 100644
--- a/tests/cases/standalone/common/promql/regex.result
+++ b/tests/cases/standalone/common/promql/regex.result
@@ -63,6 +63,7 @@ TQL EVAL (0, 100, '15s') test{host=~"(10\\.0\\.160\\.237:8080|10\\.0\\.160\\.237
 -- SQLNESS REPLACE (\s\s+) _
 -- SQLNESS REPLACE (peers.*) REDACTED
 -- SQLNESS REPLACE region=\d+\(\d+,\s+\d+\) region=REDACTED
+-- SQLNESS REPLACE (flat_format.*) REDACTED
 TQL ANALYZE VERBOSE (0, 0, '1s') test{host=~".*"};
 
 +-+-+-+
@@ -86,6 +87,7 @@ TQL ANALYZE VERBOSE (0, 0, '1s') test{host=~".*"};
 -- SQLNESS REPLACE (\s\s+) _
 -- SQLNESS REPLACE (peers.*) REDACTED
 -- SQLNESS REPLACE region=\d+\(\d+,\s+\d+\) region=REDACTED
+-- SQLNESS REPLACE (flat_format.*) REDACTED
 TQL ANALYZE VERBOSE (0, 0, '1s') test{host=~".+"};
 
 +-+-+-+
@@ -109,6 +111,7 @@ TQL ANALYZE VERBOSE (0, 0, '1s') test{host=~".+"};
 -- SQLNESS REPLACE (\s\s+) _
 -- SQLNESS REPLACE (peers.*) REDACTED
 -- SQLNESS REPLACE region=\d+\(\d+,\s+\d+\) region=REDACTED
+-- SQLNESS REPLACE (flat_format.*) REDACTED
 TQL ANALYZE VERBOSE (0, 0, '1s') test{host!~".*"};
 
 +-+-+-+
@@ -134,6 +137,7 @@ TQL ANALYZE VERBOSE (0, 0, '1s') test{host!~".*"};
 -- SQLNESS REPLACE (\s\s+) _
 -- SQLNESS REPLACE (peers.*) REDACTED
 -- SQLNESS REPLACE region=\d+\(\d+,\s+\d+\) region=REDACTED
+-- SQLNESS REPLACE (flat_format.*) REDACTED
 TQL ANALYZE VERBOSE (0, 0, '1s') test{host!~".+"};
 
 +-+-+-+
diff --git a/tests/cases/standalone/common/promql/regex.sql b/tests/cases/standalone/common/promql/regex.sql
index 3b7be2a5acd4..9804e098e640 100644
--- a/tests/cases/standalone/common/promql/regex.sql
+++ b/tests/cases/standalone/common/promql/regex.sql
@@ -26,6 +26,7 @@ TQL EVAL (0, 100, '15s') test{host=~"(10\\.0\\.160\\.237:8080|10\\.0\\.160\\.237
 -- SQLNESS REPLACE (\s\s+) _
 -- SQLNESS REPLACE (peers.*) REDACTED
 -- SQLNESS REPLACE region=\d+\(\d+,\s+\d+\) region=REDACTED
+-- SQLNESS REPLACE (flat_format.*) REDACTED
 TQL ANALYZE VERBOSE (0, 0, '1s') test{host=~".*"};
 
 -- SQLNESS REPLACE (metrics.*) REDACTED
@@ -35,6 +36,7 @@ TQL ANALYZE VERBOSE (0, 0, '1s') test{host=~".*"};
 -- SQLNESS REPLACE (\s\s+) _
 -- SQLNESS REPLACE (peers.*) REDACTED
 -- SQLNESS REPLACE region=\d+\(\d+,\s+\d+\) region=REDACTED
+-- SQLNESS REPLACE (flat_format.*) REDACTED
 TQL ANALYZE VERBOSE (0, 0, '1s') test{host=~".+"};
 
 -- SQLNESS REPLACE (metrics.*) REDACTED
@@ -44,6 +46,7 @@ TQL ANALYZE VERBOSE (0, 0, '1s') test{host=~".+"};
 -- SQLNESS REPLACE (\s\s+) _
 -- SQLNESS REPLACE (peers.*) REDACTED
 -- SQLNESS REPLACE region=\d+\(\d+,\s+\d+\) region=REDACTED
+-- SQLNESS REPLACE (flat_format.*) REDACTED
 TQL ANALYZE VERBOSE (0, 0, '1s') test{host!~".*"};
 
 -- SQLNESS REPLACE (metrics.*) REDACTED
@@ -53,6 +56,7 @@ TQL ANALYZE VERBOSE (0, 0, '1s') test{host!~".*"};
 -- SQLNESS REPLACE (\s\s+) _
 -- SQLNESS REPLACE (peers.*) REDACTED
 -- SQLNESS REPLACE region=\d+\(\d+,\s+\d+\) region=REDACTED
+-- SQLNESS REPLACE (flat_format.*) REDACTED
 TQL ANALYZE VERBOSE (0, 0, '1s') test{host!~".+"};
 
 DROP TABLE test;
diff --git a/tests/cases/standalone/tql-explain-analyze/analyze.result b/tests/cases/standalone/tql-explain-analyze/analyze.result
index 67679942d5f8..ebd39324cd2e 100644
--- a/tests/cases/standalone/tql-explain-analyze/analyze.result
+++ b/tests/cases/standalone/tql-explain-analyze/analyze.result
@@ -90,6 +90,7 @@ TQL ANALYZE ('1970-01-01T00:00:00'::timestamp, '1970-01-01T00:00:00'::timestamp
 -- SQLNESS REPLACE (Duration.*) REDACTED
 -- SQLNESS REPLACE region=\d+\(\d+,\s+\d+\) region=REDACTED
 -- SQLNESS REPLACE (Hash.*) REDACTED
+-- SQLNESS REPLACE (flat_format.*) REDACTED
 TQL ANALYZE VERBOSE (0, 10, '5s') test;
 
 +-+-+-+
@@ -208,6 +209,7 @@ TQL ANALYZE FORMAT JSON (0, 10, '5s') test;
 -- SQLNESS REPLACE (metrics.*) REDACTED
 -- SQLNESS REPLACE (Duration.*) REDACTED
 -- SQLNESS REPLACE region=\d+\(\d+,\s+\d+\) region=REDACTED
+-- SQLNESS REPLACE (flat_format.*) REDACTED
 TQL ANALYZE VERBOSE FORMAT JSON (0, 10, '5s') test;
 
 +-+-+-+
diff --git a/tests/cases/standalone/tql-explain-analyze/analyze.sql b/tests/cases/standalone/tql-explain-analyze/analyze.sql
index ad1c2fa11668..598cdf0aa984 100644
--- a/tests/cases/standalone/tql-explain-analyze/analyze.sql
+++ b/tests/cases/standalone/tql-explain-analyze/analyze.sql
@@ -44,6 +44,7 @@ TQL ANALYZE ('1970-01-01T00:00:00'::timestamp, '1970-01-01T00:00:00'::timestamp
 -- SQLNESS REPLACE (Duration.*) REDACTED
 -- SQLNESS REPLACE region=\d+\(\d+,\s+\d+\) region=REDACTED
 -- SQLNESS REPLACE (Hash.*) REDACTED
+-- SQLNESS REPLACE (flat_format.*) REDACTED
 TQL ANALYZE VERBOSE (0, 10, '5s') test;
 
 DROP TABLE test;
@@ -89,6 +90,7 @@ TQL ANALYZE FORMAT JSON (0, 10, '5s') test;
 -- SQLNESS REPLACE (metrics.*) REDACTED
 -- SQLNESS REPLACE (Duration.*) REDACTED
 -- SQLNESS REPLACE region=\d+\(\d+,\s+\d+\) region=REDACTED
+-- SQLNESS REPLACE (flat_format.*) REDACTED
 TQL ANALYZE VERBOSE FORMAT JSON (0, 10, '5s') test;
 
 -- analyze with TEXT format (should be same as default)

From 2df4c4d2ab166fd0d085ebc6e7a937bdcae5adef Mon Sep 17 00:00:00 2001
From: evenyag <realevenyag@gmail.com>
Date: Fri, 9 Jan 2026 00:06:16 +0800
Subject: [PATCH 06/10] feat: make scan cost contains part/reader build cost

Signed-off-by: evenyag <realevenyag@gmail.com>
---
 src/mito2/src/read/seq_scan.rs    | 26 ++++++++++++++++++++++----
 src/mito2/src/read/series_scan.rs |  8 ++++++--
 2 files changed, 28 insertions(+), 6 deletions(-)

diff --git a/src/mito2/src/read/seq_scan.rs b/src/mito2/src/read/seq_scan.rs
index 0031ec77af05..150d9bc87bc1 100644
--- a/src/mito2/src/read/seq_scan.rs
+++ b/src/mito2/src/read/seq_scan.rs
@@ -410,6 +410,9 @@ impl SeqScan {
 
         let stream = try_stream! {
             part_metrics.on_first_poll();
+            // Start fetch time before building sources so scan cost contains
+            // build part cost.
+            let mut fetch_start = Instant::now();
 
             let range_builder_list = Arc::new(RangeBuilderList::new(
                 stream_ctx.input.num_memtables(),
@@ -431,8 +434,6 @@ impl SeqScan {
                     file_scan_semaphore.clone(),
                 ).await?;
 
-                let mut metrics = ScannerMetrics::default();
-                let mut fetch_start = Instant::now();
                 let mut reader =
                     Self::build_reader_from_sources(&stream_ctx, sources, semaphore.clone(), Some(&part_metrics))
                         .await?;
@@ -441,6 +442,12 @@ impl SeqScan {
                     .with_start(Some(part_range.start))
                     .with_end(Some(part_range.end));
 
+                let mut metrics = ScannerMetrics {
+                    scan_cost: fetch_start.elapsed(),
+                    ..Default::default()
+                };
+                fetch_start = Instant::now();
+
                 while let Some(batch) = reader.next_batch().await? {
                     metrics.scan_cost += fetch_start.elapsed();
                     metrics.num_batches += 1;
@@ -448,6 +455,7 @@ impl SeqScan {
 
                     debug_assert!(!batch.is_empty());
                     if batch.is_empty() {
+                        fetch_start = Instant::now();
                         continue;
                     }
 
@@ -476,6 +484,7 @@ impl SeqScan {
                 }
 
                 metrics.scan_cost += fetch_start.elapsed();
+                fetch_start = Instant::now();
                 part_metrics.merge_metrics(&metrics);
             }
 
@@ -516,6 +525,9 @@ impl SeqScan {
 
         let stream = try_stream! {
             part_metrics.on_first_poll();
+            // Start fetch time before building sources so scan cost contains
+            // build part cost.
+            let mut fetch_start = Instant::now();
 
             let range_builder_list = Arc::new(RangeBuilderList::new(
                 stream_ctx.input.num_memtables(),
@@ -534,12 +546,16 @@ impl SeqScan {
                     file_scan_semaphore.clone(),
                 ).await?;
 
-                let mut metrics = ScannerMetrics::default();
-                let mut fetch_start = Instant::now();
                 let mut reader =
                     Self::build_flat_reader_from_sources(&stream_ctx, sources, semaphore.clone(), Some(&part_metrics))
                         .await?;
 
+                let mut metrics = ScannerMetrics {
+                    scan_cost: fetch_start.elapsed(),
+                    ..Default::default()
+                };
+                fetch_start = Instant::now();
+
                 while let Some(record_batch) = reader.try_next().await? {
                     metrics.scan_cost += fetch_start.elapsed();
                     metrics.num_batches += 1;
@@ -547,6 +563,7 @@ impl SeqScan {
 
                     debug_assert!(record_batch.num_rows() > 0);
                     if record_batch.num_rows() == 0 {
+                        fetch_start = Instant::now();
                         continue;
                     }
 
@@ -558,6 +575,7 @@ impl SeqScan {
                 }
 
                 metrics.scan_cost += fetch_start.elapsed();
+                fetch_start = Instant::now();
                 part_metrics.merge_metrics(&metrics);
             }
 
diff --git a/src/mito2/src/read/series_scan.rs b/src/mito2/src/read/series_scan.rs
index cb18a5fdceff..a8d7023b88ff 100644
--- a/src/mito2/src/read/series_scan.rs
+++ b/src/mito2/src/read/series_scan.rs
@@ -446,6 +446,9 @@ impl SeriesDistributor {
             &self.metrics_list,
         );
         part_metrics.on_first_poll();
+        // Start fetch time before building sources so scan cost contains
+        // build part cost.
+        let mut fetch_start = Instant::now();
 
         let range_builder_list = Arc::new(RangeBuilderList::new(
             self.stream_ctx.input.num_memtables(),
@@ -478,7 +481,6 @@ impl SeriesDistributor {
         )
         .await?;
         let mut metrics = SeriesDistributorMetrics::default();
-        let mut fetch_start = Instant::now();
 
         let mut divider = FlatSeriesBatchDivider::default();
         while let Some(record_batch) = reader.try_next().await? {
@@ -536,6 +538,9 @@ impl SeriesDistributor {
             &self.metrics_list,
         );
         part_metrics.on_first_poll();
+        // Start fetch time before building sources so scan cost contains
+        // build part cost.
+        let mut fetch_start = Instant::now();
 
         let range_builder_list = Arc::new(RangeBuilderList::new(
             self.stream_ctx.input.num_memtables(),
@@ -568,7 +573,6 @@ impl SeriesDistributor {
         )
         .await?;
         let mut metrics = SeriesDistributorMetrics::default();
-        let mut fetch_start = Instant::now();
 
         let mut current_series = PrimaryKeySeriesBatch::default();
         while let Some(batch) = reader.next_batch().await? {

From d8f92465cc2f83b86a8df40cb07c9881767e6e57 Mon Sep 17 00:00:00 2001
From: evenyag <realevenyag@gmail.com>
Date: Fri, 9 Jan 2026 00:27:29 +0800
Subject: [PATCH 07/10] feat: collect divider cost

Signed-off-by: evenyag <realevenyag@gmail.com>
---
 src/mito2/src/read/scan_util.rs   | 13 +++++++++++++
 src/mito2/src/read/series_scan.rs | 10 ++++++++--
 2 files changed, 21 insertions(+), 2 deletions(-)

diff --git a/src/mito2/src/read/scan_util.rs b/src/mito2/src/read/scan_util.rs
index 1ffd34de2f21..1486aa331392 100644
--- a/src/mito2/src/read/scan_util.rs
+++ b/src/mito2/src/read/scan_util.rs
@@ -197,6 +197,8 @@ pub(crate) struct ScanMetricsSet {
     distributor_scan_cost: Duration,
     /// Duration of the series distributor to yield.
     distributor_yield_cost: Duration,
+    /// Duration spent in divider operations.
+    distributor_divider_cost: Duration,
 
     /// Merge metrics.
     merge_metrics: MergeMetrics,
@@ -291,6 +293,7 @@ impl fmt::Debug for ScanMetricsSet {
             num_distributor_batches,
             distributor_scan_cost,
             distributor_yield_cost,
+            distributor_divider_cost,
             merge_metrics,
             dedup_metrics,
             stream_eof,
@@ -415,6 +418,12 @@ impl fmt::Debug for ScanMetricsSet {
                 ", \"distributor_yield_cost\":\"{distributor_yield_cost:?}\""
             )?;
         }
+        if !distributor_divider_cost.is_zero() {
+            write!(
+                f,
+                ", \"distributor_divider_cost\":\"{distributor_divider_cost:?}\""
+            )?;
+        }
 
         // Write non-zero memtable metrics
         if *mem_rows > 0 {
@@ -658,6 +667,7 @@ impl ScanMetricsSet {
             num_batches,
             scan_cost,
             yield_cost,
+            divider_cost,
         } = distributor_metrics;
 
         self.num_series_send_timeout += *num_series_send_timeout;
@@ -666,6 +676,7 @@ impl ScanMetricsSet {
         self.num_distributor_batches += *num_batches;
         self.distributor_scan_cost += *scan_cost;
         self.distributor_yield_cost += *yield_cost;
+        self.distributor_divider_cost += *divider_cost;
     }
 
     /// Observes metrics.
@@ -1014,6 +1025,8 @@ pub(crate) struct SeriesDistributorMetrics {
     pub(crate) scan_cost: Duration,
     /// Duration of the series distributor to yield.
     pub(crate) yield_cost: Duration,
+    /// Duration spent in divider operations.
+    pub(crate) divider_cost: Duration,
 }
 
 /// Scans memtable ranges at `index`.
diff --git a/src/mito2/src/read/series_scan.rs b/src/mito2/src/read/series_scan.rs
index a8d7023b88ff..faffd2805c8c 100644
--- a/src/mito2/src/read/series_scan.rs
+++ b/src/mito2/src/read/series_scan.rs
@@ -495,7 +495,10 @@ impl SeriesDistributor {
             }
 
             // Use divider to split series
-            if let Some(series_batch) = divider.push(record_batch) {
+            let divider_start = Instant::now();
+            let series_batch = divider.push(record_batch);
+            metrics.divider_cost += divider_start.elapsed();
+            if let Some(series_batch) = series_batch {
                 let yield_start = Instant::now();
                 self.senders
                     .send_batch(SeriesBatch::Flat(series_batch))
@@ -506,7 +509,10 @@ impl SeriesDistributor {
         }
 
         // Send any remaining batch in the divider
-        if let Some(series_batch) = divider.finish() {
+        let divider_start = Instant::now();
+        let series_batch = divider.finish();
+        metrics.divider_cost += divider_start.elapsed();
+        if let Some(series_batch) = series_batch {
             let yield_start = Instant::now();
             self.senders
                 .send_batch(SeriesBatch::Flat(series_batch))

From 94749c9829a4e814dfcf07ac983af17aeb60d3d3 Mon Sep 17 00:00:00 2001
From: evenyag <realevenyag@gmail.com>
Date: Fri, 9 Jan 2026 00:39:15 +0800
Subject: [PATCH 08/10] refactor: remove unused field in ScannerMetrics

Signed-off-by: evenyag <realevenyag@gmail.com>
---
 src/mito2/src/read.rs           |  8 --------
 src/mito2/src/read/scan_util.rs | 11 -----------
 2 files changed, 19 deletions(-)

diff --git a/src/mito2/src/read.rs b/src/mito2/src/read.rs
index 06d615452add..16eda0839061 100644
--- a/src/mito2/src/read.rs
+++ b/src/mito2/src/read.rs
@@ -1058,10 +1058,6 @@ impl<T: BatchReader + ?Sized> BatchReader for Box<T> {
 /// Local metrics for scanners.
 #[derive(Debug, Default)]
 pub(crate) struct ScannerMetrics {
-    /// Duration to prepare the scan task.
-    prepare_scan_cost: Duration,
-    /// Duration to build the (merge) reader.
-    build_reader_cost: Duration,
     /// Duration to scan data.
     scan_cost: Duration,
     /// Duration while waiting for `yield`.
@@ -1070,10 +1066,6 @@ pub(crate) struct ScannerMetrics {
     num_batches: usize,
     /// Number of rows returned.
     num_rows: usize,
-    /// Number of mem ranges scanned.
-    num_mem_ranges: usize,
-    /// Number of file ranges scanned.
-    num_file_ranges: usize,
 }
 
 #[cfg(test)]
diff --git a/src/mito2/src/read/scan_util.rs b/src/mito2/src/read/scan_util.rs
index 1486aa331392..1e5e79bfae4a 100644
--- a/src/mito2/src/read/scan_util.rs
+++ b/src/mito2/src/read/scan_util.rs
@@ -541,24 +541,16 @@ impl ScanMetricsSet {
     /// Merges the local scanner metrics.
     fn merge_scanner_metrics(&mut self, other: &ScannerMetrics) {
         let ScannerMetrics {
-            prepare_scan_cost,
-            build_reader_cost,
             scan_cost,
             yield_cost,
             num_batches,
             num_rows,
-            num_mem_ranges,
-            num_file_ranges,
         } = other;
 
-        self.prepare_scan_cost += *prepare_scan_cost;
-        self.build_reader_cost += *build_reader_cost;
         self.scan_cost += *scan_cost;
         self.yield_cost += *yield_cost;
         self.num_rows += *num_rows;
         self.num_batches += *num_batches;
-        self.num_mem_ranges += *num_mem_ranges;
-        self.num_file_ranges += *num_file_ranges;
     }
 
     /// Merges the local reader metrics.
@@ -943,9 +935,6 @@ impl PartitionMetrics {
 
     /// Merges [ScannerMetrics], `build_reader_cost`, `scan_cost` and `yield_cost`.
     pub(crate) fn merge_metrics(&self, metrics: &ScannerMetrics) {
-        self.0
-            .build_reader_cost
-            .add_duration(metrics.build_reader_cost);
         self.0.scan_cost.add_duration(metrics.scan_cost);
         self.record_elapsed_compute(metrics.scan_cost);
         self.0.yield_cost.add_duration(metrics.yield_cost);

From b827fbd5086112898322596e64c10313add96de1 Mon Sep 17 00:00:00 2001
From: evenyag <realevenyag@gmail.com>
Date: Mon, 12 Jan 2026 22:20:08 +0800
Subject: [PATCH 09/10] feat: collect metadata read bytes

Signed-off-by: evenyag <realevenyag@gmail.com>
---
 src/mito2/src/cache/file_cache.rs     |  5 ++++-
 src/mito2/src/sst/parquet/metadata.rs | 25 ++++++++++++++++++++++---
 src/mito2/src/sst/parquet/reader.rs   | 16 +++++++++++++++-
 3 files changed, 41 insertions(+), 5 deletions(-)

diff --git a/src/mito2/src/cache/file_cache.rs b/src/mito2/src/cache/file_cache.rs
index 58a2dac58842..23e52dfe3cae 100644
--- a/src/mito2/src/cache/file_cache.rs
+++ b/src/mito2/src/cache/file_cache.rs
@@ -43,6 +43,7 @@ use crate::metrics::{
 use crate::region::opener::RegionLoadCacheTask;
 use crate::sst::parquet::helper::fetch_byte_ranges;
 use crate::sst::parquet::metadata::MetadataLoader;
+use crate::sst::parquet::reader::MetadataCacheMetrics;
 
 /// Subdirectory of cached files for write.
 ///
@@ -575,7 +576,9 @@ impl FileCache {
             let file_size = index_value.file_size as u64;
             let metadata_loader = MetadataLoader::new(local_store, &file_path, file_size);
 
-            match metadata_loader.load().await {
+            // We don't need to track metrics when loading from file cache.
+            let mut cache_metrics = MetadataCacheMetrics::default();
+            match metadata_loader.load(&mut cache_metrics).await {
                 Ok(metadata) => {
                     CACHE_HIT
                         .with_label_values(&[key.file_type.metric_label()])
diff --git a/src/mito2/src/sst/parquet/metadata.rs b/src/mito2/src/sst/parquet/metadata.rs
index 05c7aac46239..0ab666b31065 100644
--- a/src/mito2/src/sst/parquet/metadata.rs
+++ b/src/mito2/src/sst/parquet/metadata.rs
@@ -13,6 +13,7 @@
 // limitations under the License.
 
 use std::result::Result as StdResult;
+use std::sync::atomic::{AtomicU64, AtomicUsize, Ordering};
 
 use bytes::Bytes;
 use futures::FutureExt;
@@ -24,6 +25,7 @@ use parquet::file::metadata::{ParquetMetaData, ParquetMetaDataReader};
 use snafu::{IntoError as _, ResultExt};
 
 use crate::error::{self, Result};
+use crate::sst::parquet::reader::MetadataCacheMetrics;
 
 /// The estimated size of the footer and metadata need to read from the end of parquet file.
 const DEFAULT_PREFETCH_SIZE: u64 = 64 * 1024;
@@ -65,24 +67,36 @@ impl<'a> MetadataLoader<'a> {
         Ok(file_size)
     }
 
-    pub async fn load(&self) -> Result<ParquetMetaData> {
+    pub async fn load(
+        &self,
+        cache_metrics: &mut MetadataCacheMetrics,
+    ) -> Result<ParquetMetaData> {
         let path = self.file_path;
         let file_size = self.get_file_size().await?;
         let reader =
             ParquetMetaDataReader::new().with_prefetch_hint(Some(DEFAULT_PREFETCH_SIZE as usize));
 
+        let num_reads = AtomicUsize::new(0);
+        let bytes_read = AtomicU64::new(0);
         let fetch = ObjectStoreFetch {
             object_store: &self.object_store,
             file_path: self.file_path,
+            num_reads: &num_reads,
+            bytes_read: &bytes_read,
         };
 
-        reader
+        let metadata = reader
             .load_and_finish(fetch, file_size)
             .await
             .map_err(|e| match unbox_external_error(e) {
                 Ok(os_err) => error::OpenDalSnafu {}.into_error(os_err),
                 Err(parquet_err) => error::ReadParquetSnafu { path }.into_error(parquet_err),
-            })
+            })?;
+
+        cache_metrics.num_reads = num_reads.into_inner();
+        cache_metrics.bytes_read = bytes_read.into_inner();
+
+        Ok(metadata)
     }
 }
 
@@ -100,10 +114,13 @@ fn unbox_external_error(e: ParquetError) -> StdResult<object_store::Error, Parqu
 struct ObjectStoreFetch<'a> {
     object_store: &'a ObjectStore,
     file_path: &'a str,
+    num_reads: &'a AtomicUsize,
+    bytes_read: &'a AtomicU64,
 }
 
 impl MetadataFetch for ObjectStoreFetch<'_> {
     fn fetch(&mut self, range: std::ops::Range<u64>) -> BoxFuture<'_, ParquetResult<Bytes>> {
+        let bytes_to_read = range.end - range.start;
         async move {
             let data = self
                 .object_store
@@ -111,6 +128,8 @@ impl MetadataFetch for ObjectStoreFetch<'_> {
                 .range(range)
                 .await
                 .map_err(|e| ParquetError::External(Box::new(e)))?;
+            self.num_reads.fetch_add(1, Ordering::Relaxed);
+            self.bytes_read.fetch_add(bytes_to_read, Ordering::Relaxed);
             Ok(data.to_bytes())
         }
         .boxed()
diff --git a/src/mito2/src/sst/parquet/reader.rs b/src/mito2/src/sst/parquet/reader.rs
index 6a0e5395a792..6111fa200bbc 100644
--- a/src/mito2/src/sst/parquet/reader.rs
+++ b/src/mito2/src/sst/parquet/reader.rs
@@ -468,7 +468,7 @@ impl ParquetReaderBuilder {
 
         // Cache miss, load metadata directly.
         let metadata_loader = MetadataLoader::new(self.object_store.clone(), file_path, file_size);
-        let metadata = metadata_loader.load().await?;
+        let metadata = metadata_loader.load(cache_metrics).await?;
 
         let metadata = Arc::new(metadata);
         // Cache the metadata.
@@ -1154,6 +1154,10 @@ pub(crate) struct MetadataCacheMetrics {
     pub(crate) cache_miss: usize,
     /// Duration to load parquet metadata.
     pub(crate) metadata_load_cost: Duration,
+    /// Number of read operations performed.
+    pub(crate) num_reads: usize,
+    /// Total bytes read from storage.
+    pub(crate) bytes_read: u64,
 }
 
 impl std::fmt::Debug for MetadataCacheMetrics {
@@ -1163,6 +1167,8 @@ impl std::fmt::Debug for MetadataCacheMetrics {
             file_cache_hit,
             cache_miss,
             metadata_load_cost,
+            num_reads,
+            bytes_read,
         } = self;
 
         if self.is_empty() {
@@ -1181,6 +1187,12 @@ impl std::fmt::Debug for MetadataCacheMetrics {
         if *cache_miss > 0 {
             write!(f, ", \"cache_miss\":{}", cache_miss)?;
         }
+        if *num_reads > 0 {
+            write!(f, ", \"num_reads\":{}", num_reads)?;
+        }
+        if *bytes_read > 0 {
+            write!(f, ", \"bytes_read\":{}", bytes_read)?;
+        }
 
         write!(f, "}}")
     }
@@ -1198,6 +1210,8 @@ impl MetadataCacheMetrics {
         self.file_cache_hit += other.file_cache_hit;
         self.cache_miss += other.cache_miss;
         self.metadata_load_cost += other.metadata_load_cost;
+        self.num_reads += other.num_reads;
+        self.bytes_read += other.bytes_read;
     }
 }
 

From 2db156bba4f33d11185e4a8365d0bf12abec69f7 Mon Sep 17 00:00:00 2001
From: evenyag <realevenyag@gmail.com>
Date: Mon, 12 Jan 2026 22:47:34 +0800
Subject: [PATCH 10/10] chore: collect read metrics in get_parquet_meta_data

Signed-off-by: evenyag <realevenyag@gmail.com>
---
 src/mito2/src/cache.rs                  |  5 ++++-
 src/mito2/src/cache/file_cache.rs       | 10 ++++++----
 src/mito2/src/sst/parquet/metadata.rs   |  5 +----
 src/mito2/src/worker/handle_manifest.rs |  3 ++-
 4 files changed, 13 insertions(+), 10 deletions(-)

diff --git a/src/mito2/src/cache.rs b/src/mito2/src/cache.rs
index f502fb51f500..a61872e4c251 100644
--- a/src/mito2/src/cache.rs
+++ b/src/mito2/src/cache.rs
@@ -335,7 +335,10 @@ impl CacheManager {
         // Try to get metadata from write cache
         let key = IndexKey::new(file_id.region_id(), file_id.file_id(), FileType::Parquet);
         if let Some(write_cache) = &self.write_cache
-            && let Some(metadata) = write_cache.file_cache().get_parquet_meta_data(key).await
+            && let Some(metadata) = write_cache
+                .file_cache()
+                .get_parquet_meta_data(key, metrics)
+                .await
         {
             metrics.file_cache_hit += 1;
             let metadata = Arc::new(metadata);
diff --git a/src/mito2/src/cache/file_cache.rs b/src/mito2/src/cache/file_cache.rs
index 23e52dfe3cae..aeea238fdc25 100644
--- a/src/mito2/src/cache/file_cache.rs
+++ b/src/mito2/src/cache/file_cache.rs
@@ -567,7 +567,11 @@ impl FileCache {
 
     /// Get the parquet metadata in file cache.
     /// If the file is not in the cache or fail to load metadata, return None.
-    pub(crate) async fn get_parquet_meta_data(&self, key: IndexKey) -> Option<ParquetMetaData> {
+    pub(crate) async fn get_parquet_meta_data(
+        &self,
+        key: IndexKey,
+        cache_metrics: &mut MetadataCacheMetrics,
+    ) -> Option<ParquetMetaData> {
         // Check if file cache contains the key
         if let Some(index_value) = self.inner.parquet_index.get(&key).await {
             // Load metadata from file cache
@@ -576,9 +580,7 @@ impl FileCache {
             let file_size = index_value.file_size as u64;
             let metadata_loader = MetadataLoader::new(local_store, &file_path, file_size);
 
-            // We don't need to track metrics when loading from file cache.
-            let mut cache_metrics = MetadataCacheMetrics::default();
-            match metadata_loader.load(&mut cache_metrics).await {
+            match metadata_loader.load(cache_metrics).await {
                 Ok(metadata) => {
                     CACHE_HIT
                         .with_label_values(&[key.file_type.metric_label()])
diff --git a/src/mito2/src/sst/parquet/metadata.rs b/src/mito2/src/sst/parquet/metadata.rs
index 0ab666b31065..1e85b778014c 100644
--- a/src/mito2/src/sst/parquet/metadata.rs
+++ b/src/mito2/src/sst/parquet/metadata.rs
@@ -67,10 +67,7 @@ impl<'a> MetadataLoader<'a> {
         Ok(file_size)
     }
 
-    pub async fn load(
-        &self,
-        cache_metrics: &mut MetadataCacheMetrics,
-    ) -> Result<ParquetMetaData> {
+    pub async fn load(&self, cache_metrics: &mut MetadataCacheMetrics) -> Result<ParquetMetaData> {
         let path = self.file_path;
         let file_size = self.get_file_size().await?;
         let reader =
diff --git a/src/mito2/src/worker/handle_manifest.rs b/src/mito2/src/worker/handle_manifest.rs
index 85bda50f1a40..92e7ca9b9dfd 100644
--- a/src/mito2/src/worker/handle_manifest.rs
+++ b/src/mito2/src/worker/handle_manifest.rs
@@ -520,9 +520,10 @@ async fn edit_region(
                 {
                     // Triggers the filling of the parquet metadata cache.
                     // The parquet file is already downloaded.
+                    let mut cache_metrics = Default::default();
                     let _ = write_cache
                         .file_cache()
-                        .get_parquet_meta_data(index_key)
+                        .get_parquet_meta_data(index_key, &mut cache_metrics)
                         .await;
 
                     listener.on_file_cache_filled(index_key.file_id);