diff --git a/src/storage/hummock_sdk/src/key_cmp.rs b/src/storage/hummock_sdk/src/key_cmp.rs
index bc18350f9839b..a6b7377170412 100644
--- a/src/storage/hummock_sdk/src/key_cmp.rs
+++ b/src/storage/hummock_sdk/src/key_cmp.rs
@@ -15,7 +15,7 @@
 use std::cmp::{self, Ordering};
 
 use super::key::split_key_epoch;
-use crate::key::{FullKey, UserKey};
+use crate::key::UserKey;
 
 /// A comparator for comparing [`FullKey`] and [`UserKey`] with possibly different table key types.
 pub struct KeyComparator;
@@ -30,16 +30,6 @@ impl KeyComparator {
         l_p.cmp(r_p).then_with(|| r_s.cmp(l_s))
     }
 
-    pub fn compare_full_key_without_table_id(
-        lhs: FullKey<&[u8]>,
-        rhs: FullKey<&[u8]>,
-    ) -> cmp::Ordering {
-        lhs.user_key
-            .table_key
-            .cmp(&rhs.user_key.table_key)
-            .then_with(|| rhs.epoch.cmp(&lhs.epoch))
-    }
-
     /// Used to compare [`UserKey`] and its encoded format.
     pub fn compare_user_key_cross_format(
         encoded: impl AsRef<[u8]>,
diff --git a/src/storage/src/hummock/compactor/compaction_utils.rs b/src/storage/src/hummock/compactor/compaction_utils.rs
index 2ba9420e439c8..da8307896e188 100644
--- a/src/storage/src/hummock/compactor/compaction_utils.rs
+++ b/src/storage/src/hummock/compactor/compaction_utils.rs
@@ -25,7 +25,7 @@ use risingwave_hummock_sdk::key::FullKey;
 use risingwave_hummock_sdk::key_range::KeyRange;
 use risingwave_hummock_sdk::prost_key_range::KeyRangeExt;
 use risingwave_hummock_sdk::table_stats::TableStatsMap;
-use risingwave_hummock_sdk::HummockEpoch;
+use risingwave_hummock_sdk::{HummockEpoch, KeyComparator};
 use risingwave_pb::hummock::{compact_task, CompactTask, KeyRange as KeyRange_vec, LevelType};
 
 pub use super::context::CompactorContext;
@@ -219,7 +219,7 @@ pub async fn generate_splits(compact_task: &mut CompactTask, context: Arc<Compac
             );
         }
         // sort by key, as for every data block has the same size;
-        indexes.sort_by(|a, b| FullKey::decode(a.1.as_ref()).cmp(&FullKey::decode(b.1.as_ref())));
+        indexes.sort_by(|a, b| KeyComparator::compare_encoded_full_key(a.1.as_ref(), b.1.as_ref()));
         let mut splits: Vec<KeyRange_vec> = vec![];
         splits.push(KeyRange_vec::new(vec![], vec![]));
         let parallelism = std::cmp::min(
diff --git a/src/storage/src/hummock/compactor/iterator.rs b/src/storage/src/hummock/compactor/iterator.rs
index 5826f577d0398..c2447bcd8727a 100644
--- a/src/storage/src/hummock/compactor/iterator.rs
+++ b/src/storage/src/hummock/compactor/iterator.rs
@@ -20,6 +20,7 @@ use std::time::Instant;
 
 use risingwave_hummock_sdk::key::FullKey;
 use risingwave_hummock_sdk::key_range::KeyRange;
+use risingwave_hummock_sdk::KeyComparator;
 use risingwave_pb::hummock::SstableInfo;
 
 use crate::hummock::iterator::{Forward, HummockIterator};
@@ -261,9 +262,10 @@ impl ConcatSstableIterator {
                 block_metas.len()
             } else {
                 block_metas.partition_point(|block| {
-                    FullKey::decode(&block.smallest_key)
-                        .cmp(&FullKey::decode(&self.key_range.right))
-                        != Ordering::Greater
+                    KeyComparator::compare_encoded_full_key(
+                        &block.smallest_key,
+                        &self.key_range.right,
+                    ) != Ordering::Greater
                 })
             };
             if end_index <= start_index {
diff --git a/src/storage/src/hummock/sstable/block.rs b/src/storage/src/hummock/sstable/block.rs
index 13beb4f2cada0..cdb36807f5a66 100644
--- a/src/storage/src/hummock/sstable/block.rs
+++ b/src/storage/src/hummock/sstable/block.rs
@@ -450,13 +450,7 @@ impl BlockBuilder {
         if self.entry_count > 0 {
             debug_assert!(!key.is_empty());
             debug_assert_eq!(
-                KeyComparator::compare_full_key_without_table_id(
-                    FullKey::from_slice_without_table_id(
-                        TableId::new(input_table_id),
-                        &self.last_key[..]
-                    ),
-                    full_key
-                ),
+                KeyComparator::compare_encoded_full_key(&self.last_key[..], &key[..]),
                 Ordering::Less
             );
         }