diff --git a/milli/src/update/index_documents/cache.rs b/milli/src/update/index_documents/cache.rs
index dc4404ab2..7c57c0b3e 100644
--- a/milli/src/update/index_documents/cache.rs
+++ b/milli/src/update/index_documents/cache.rs
@@ -11,7 +11,7 @@ use smallvec::SmallVec;
 use crate::update::del_add::{DelAdd, KvWriterDelAdd};
 use crate::CboRoaringBitmapCodec;
 
-const DISABLED: bool = true;
+const ENABLED: bool = true;
 
 pub struct SorterCacheDelAddCboRoaringBitmap<const N: usize, MF> {
     cache: ArcCache<SmallVec<[u8; N]>, DelAddRoaringBitmap>,
@@ -45,7 +45,7 @@ where
     MF: for<'a> Fn(&[u8], &[Cow<'a, [u8]>]) -> Result<Cow<'a, [u8]>, U>,
 {
     pub fn insert_del_u32(&mut self, key: &[u8], n: u32) -> Result<(), grenad::Error<U>> {
-        if DISABLED {
+        if !ENABLED {
             return self.write_entry_to_sorter(key, DelAddRoaringBitmap::new_del_u32(n));
         }
 
@@ -73,7 +73,7 @@ where
         key: &[u8],
         bitmap: RoaringBitmap,
     ) -> Result<(), grenad::Error<U>> {
-        if DISABLED {
+        if !ENABLED {
             return self.write_entry_to_sorter(key, DelAddRoaringBitmap::new_del(bitmap));
         }
 
@@ -97,7 +97,7 @@ where
     }
 
     pub fn insert_add_u32(&mut self, key: &[u8], n: u32) -> Result<(), grenad::Error<U>> {
-        if DISABLED {
+        if !ENABLED {
             return self.write_entry_to_sorter(key, DelAddRoaringBitmap::new_add_u32(n));
         }
 
@@ -125,7 +125,7 @@ where
         key: &[u8],
         bitmap: RoaringBitmap,
     ) -> Result<(), grenad::Error<U>> {
-        if DISABLED {
+        if !ENABLED {
             return self.write_entry_to_sorter(key, DelAddRoaringBitmap::new_add(bitmap));
         }
 
@@ -149,7 +149,7 @@ where
     }
 
     pub fn insert_del_add_u32(&mut self, key: &[u8], n: u32) -> Result<(), grenad::Error<U>> {
-        if DISABLED {
+        if !ENABLED {
             return self.write_entry_to_sorter(key, DelAddRoaringBitmap::new_del_add_u32(n));
         }
 
diff --git a/milli/src/update/index_documents/extract/extract_docid_word_positions.rs b/milli/src/update/index_documents/extract/extract_docid_word_positions.rs
index 76d74bcd4..51b901f87 100644
--- a/milli/src/update/index_documents/extract/extract_docid_word_positions.rs
+++ b/milli/src/update/index_documents/extract/extract_docid_word_positions.rs
@@ -150,7 +150,9 @@ pub fn extract_docid_word_positions<R: io::Read + io::Seek>(
         for (field_id, value) in obkv.iter() {
             key_buffer.truncate(mem::size_of::<u32>());
             key_buffer.extend_from_slice(&field_id.to_be_bytes());
-            conn.merge(key_buffer.as_slice(), 1u32.to_ne_bytes()).unwrap();
+            let mut key = b"dwp".to_vec();
+            key.extend_from_slice(&key_buffer);
+            conn.merge(key, 1u32.to_ne_bytes()).unwrap();
             docid_word_positions_sorter.insert(&key_buffer, value)?;
         }
 
diff --git a/milli/src/update/index_documents/extract/extract_facet_string_docids.rs b/milli/src/update/index_documents/extract/extract_facet_string_docids.rs
index 52e734269..8adfd6ae0 100644
--- a/milli/src/update/index_documents/extract/extract_facet_string_docids.rs
+++ b/milli/src/update/index_documents/extract/extract_facet_string_docids.rs
@@ -106,7 +106,9 @@ pub fn extract_facet_string_docids<R: io::Read + io::Seek>(
 
             let key = (field_id, hyper_normalized_value.as_ref());
             let key_bytes = BEU16StrCodec::bytes_encode(&key).map_err(heed::Error::Encoding)?;
-            conn.merge(key_bytes.as_ref(), 1u32.to_ne_bytes()).unwrap();
+            let mut key = b"nfs".to_vec();
+            key.extend_from_slice(&key_bytes);
+            conn.merge(key, 1u32.to_ne_bytes()).unwrap();
             normalized_facet_string_docids_sorter.insert(key_bytes, &buffer)?;
         }
 
diff --git a/milli/src/update/index_documents/extract/extract_fid_docid_facet_values.rs b/milli/src/update/index_documents/extract/extract_fid_docid_facet_values.rs
index c3b21c9e2..e99cb537f 100644
--- a/milli/src/update/index_documents/extract/extract_fid_docid_facet_values.rs
+++ b/milli/src/update/index_documents/extract/extract_fid_docid_facet_values.rs
@@ -366,7 +366,9 @@ where
                     let mut obkv = KvWriterDelAdd::memory();
                     obkv.insert(DelAdd::Deletion, bytes_of(&()))?;
                     let bytes = obkv.into_inner()?;
-                    conn.merge(key_buffer.as_slice(), 1u32.to_ne_bytes()).unwrap();
+                    let mut key = b"dfn".to_vec();
+                    key.extend_from_slice(key_buffer);
+                    conn.merge(key, 1u32.to_ne_bytes()).unwrap();
                     fid_docid_facet_numbers_sorter.insert(&key_buffer, bytes)?;
                 }
             }
@@ -380,7 +382,9 @@ where
                     let mut obkv = KvWriterDelAdd::memory();
                     obkv.insert(DelAdd::Addition, bytes_of(&()))?;
                     let bytes = obkv.into_inner()?;
-                    conn.merge(key_buffer.as_slice(), 1u32.to_ne_bytes()).unwrap();
+                    let mut key = b"dfn".to_vec();
+                    key.extend_from_slice(key_buffer);
+                    conn.merge(key, 1u32.to_ne_bytes()).unwrap();
                     fid_docid_facet_numbers_sorter.insert(&key_buffer, bytes)?;
                 }
             }
@@ -426,7 +430,9 @@ where
                 let mut obkv = KvWriterDelAdd::memory();
                 obkv.insert(DelAdd::Deletion, original)?;
                 let bytes = obkv.into_inner()?;
-                conn.merge(key_buffer.as_slice(), 1u32.to_ne_bytes()).unwrap();
+                let mut key = b"dfs".to_vec();
+                key.extend_from_slice(key_buffer);
+                conn.merge(key, 1u32.to_ne_bytes()).unwrap();
                 fid_docid_facet_strings_sorter.insert(&key_buffer, bytes)?;
             }
             EitherOrBoth::Right((normalized, original)) => {
@@ -436,7 +442,9 @@ where
                 let mut obkv = KvWriterDelAdd::memory();
                 obkv.insert(DelAdd::Addition, original)?;
                 let bytes = obkv.into_inner()?;
-                conn.merge(key_buffer.as_slice(), 1u32.to_ne_bytes()).unwrap();
+                let mut key = b"dfs".to_vec();
+                key.extend_from_slice(key_buffer);
+                conn.merge(key, 1u32.to_ne_bytes()).unwrap();
                 fid_docid_facet_strings_sorter.insert(&key_buffer, bytes)?;
             }
         }
diff --git a/milli/src/update/index_documents/extract/extract_word_docids.rs b/milli/src/update/index_documents/extract/extract_word_docids.rs
index 15d165513..1e38706f2 100644
--- a/milli/src/update/index_documents/extract/extract_word_docids.rs
+++ b/milli/src/update/index_documents/extract/extract_word_docids.rs
@@ -253,7 +253,9 @@ where
     }
 
     // insert everything in the same writer.
-    conn.merge(word.as_bytes(), 1u32.to_ne_bytes()).unwrap();
+    let mut key = b"wod".to_vec();
+    key.extend_from_slice(word.as_bytes());
+    conn.merge(key, 1u32.to_ne_bytes()).unwrap();
     writer.insert(word.as_bytes(), obkv.into_inner().unwrap())?;
 
     Ok(())
diff --git a/milli/src/update/index_documents/extract/mod.rs b/milli/src/update/index_documents/extract/mod.rs
index 1ad6ec84d..73f9981be 100644
--- a/milli/src/update/index_documents/extract/mod.rs
+++ b/milli/src/update/index_documents/extract/mod.rs
@@ -43,11 +43,11 @@ pub static SLED_DB: once_cell::sync::Lazy<sled::Db> = once_cell::sync::Lazy::new
     ) -> Option<Vec<u8>> {
         let current_count = old_value.map_or(0, |b| b.try_into().map(u32::from_ne_bytes).unwrap());
         let new_count = merged_bytes.try_into().map(u32::from_ne_bytes).unwrap();
-        let count = current_count.saturating_add(new_count).to_be_bytes();
+        let count = current_count.saturating_add(new_count).to_ne_bytes();
         Some(count.to_vec())
     }
 
-    let db = sled::open("write-stats").unwrap();
+    let db = sled::open("write-stats.sled").unwrap();
     db.set_merge_operator(increment_u32);
     db
 });