diff --git a/filter-parser/src/lib.rs b/filter-parser/src/lib.rs
index 9a3e0f1f8..c595cf827 100644
--- a/filter-parser/src/lib.rs
+++ b/filter-parser/src/lib.rs
@@ -401,7 +401,7 @@ pub mod tests {
     fn parse() {
         use FilterCondition as Fc;
 
-        fn p<'a>(s: &'a str) -> impl std::fmt::Display + 'a {
+        fn p(s: &str) -> impl std::fmt::Display + '_ {
             Fc::parse(s).unwrap().unwrap()
         }
 
@@ -494,7 +494,7 @@ pub mod tests {
     fn error() {
         use FilterCondition as Fc;
 
-        fn p<'a>(s: &'a str) -> impl std::fmt::Display + 'a {
+        fn p(s: &str) -> impl std::fmt::Display + '_ {
             Fc::parse(s).unwrap_err().to_string()
         }
 
diff --git a/milli/src/heed_codec/facet/mod.rs b/milli/src/heed_codec/facet/mod.rs
index 4609bfe7f..d36ec8434 100644
--- a/milli/src/heed_codec/facet/mod.rs
+++ b/milli/src/heed_codec/facet/mod.rs
@@ -88,8 +88,7 @@ impl<'a> heed::BytesEncode<'a> for FacetGroupValueCodec {
     type EItem = FacetGroupValue;
 
     fn bytes_encode(value: &'a Self::EItem) -> Option<Cow<'a, [u8]>> {
-        let mut v = vec![];
-        v.push(value.size);
+        let mut v = vec![value.size];
         CboRoaringBitmapCodec::serialize_into(&value.bitmap, &mut v);
         Some(Cow::Owned(v))
     }
diff --git a/milli/src/search/facet/facet_distribution_iter.rs b/milli/src/search/facet/facet_distribution_iter.rs
index 9cd85b667..6e209c7aa 100644
--- a/milli/src/search/facet/facet_distribution_iter.rs
+++ b/milli/src/search/facet/facet_distribution_iter.rs
@@ -38,9 +38,9 @@ where
 
     if let Some(first_bound) = get_first_facet_value::<ByteSliceRefCodec>(rtxn, db, field_id)? {
         fd.iterate(candidates, highest_level, first_bound, usize::MAX)?;
-        return Ok(());
+        Ok(())
     } else {
-        return Ok(());
+        Ok(())
     }
 }
 
@@ -84,7 +84,7 @@ where
                 }
             }
         }
-        return Ok(ControlFlow::Continue(()));
+        Ok(ControlFlow::Continue(()))
     }
     fn iterate(
         &mut self,
@@ -98,7 +98,7 @@ where
         }
         let starting_key =
             FacetGroupKey { field_id: self.field_id, level, left_bound: starting_bound };
-        let iter = self.db.range(&self.rtxn, &(&starting_key..)).unwrap().take(group_size);
+        let iter = self.db.range(self.rtxn, &(&starting_key..)).unwrap().take(group_size);
 
         for el in iter {
             let (key, value) = el.unwrap();
@@ -108,7 +108,7 @@ where
                 return Ok(ControlFlow::Break(()));
             }
             let docids_in_common = value.bitmap & candidates;
-            if docids_in_common.len() > 0 {
+            if !docids_in_common.is_empty() {
                 let cf = self.iterate(
                     &docids_in_common,
                     level - 1,
@@ -121,8 +121,7 @@ where
                 }
             }
         }
-
-        return Ok(ControlFlow::Continue(()));
+        Ok(ControlFlow::Continue(()))
     }
 }
 
diff --git a/milli/src/search/facet/facet_range_search.rs b/milli/src/search/facet/facet_range_search.rs
index 07300e920..e8eeab1cc 100644
--- a/milli/src/search/facet/facet_range_search.rs
+++ b/milli/src/search/facet/facet_range_search.rs
@@ -60,7 +60,7 @@ where
         f.run(highest_level, starting_left_bound, rightmost_bound, group_size)?;
         Ok(())
     } else {
-        return Ok(());
+        Ok(())
     }
 }
 
@@ -77,7 +77,7 @@ impl<'t, 'b, 'bitmap> FacetRangeSearch<'t, 'b, 'bitmap> {
     fn run_level_0(&mut self, starting_left_bound: &'t [u8], group_size: usize) -> Result<()> {
         let left_key =
             FacetGroupKey { field_id: self.field_id, level: 0, left_bound: starting_left_bound };
-        let iter = self.db.range(&self.rtxn, &(left_key..))?.take(group_size);
+        let iter = self.db.range(self.rtxn, &(left_key..))?.take(group_size);
         for el in iter {
             let (key, value) = el?;
             // the right side of the iter range is unbounded, so we need to make sure that we are not iterating
@@ -145,7 +145,7 @@ impl<'t, 'b, 'bitmap> FacetRangeSearch<'t, 'b, 'bitmap> {
 
         let left_key =
             FacetGroupKey { field_id: self.field_id, level, left_bound: starting_left_bound };
-        let mut iter = self.db.range(&self.rtxn, &(left_key..))?.take(group_size);
+        let mut iter = self.db.range(self.rtxn, &(left_key..))?.take(group_size);
 
         // We iterate over the range while keeping in memory the previous value
         let (mut previous_key, mut previous_value) = iter.next().unwrap()?;
@@ -348,6 +348,7 @@ mod tests {
                     &mut docids,
                 )
                 .unwrap();
+                #[allow(clippy::format_push_string)]
                 results.push_str(&format!("{}\n", display_bitmap(&docids)));
             }
             milli_snap!(results, format!("included_{i}"));
@@ -366,6 +367,7 @@ mod tests {
                     &mut docids,
                 )
                 .unwrap();
+                #[allow(clippy::format_push_string)]
                 results.push_str(&format!("{}\n", display_bitmap(&docids)));
             }
             milli_snap!(results, format!("excluded_{i}"));
diff --git a/milli/src/search/facet/facet_sort_ascending.rs b/milli/src/search/facet/facet_sort_ascending.rs
index 2f1f73db3..552795981 100644
--- a/milli/src/search/facet/facet_sort_ascending.rs
+++ b/milli/src/search/facet/facet_sort_ascending.rs
@@ -50,6 +50,7 @@ struct AscendingFacetSort<'t, 'e> {
     rtxn: &'t heed::RoTxn<'e>,
     db: heed::Database<FacetGroupKeyCodec<ByteSliceRefCodec>, FacetGroupValueCodec>,
     field_id: u16,
+    #[allow(clippy::type_complexity)]
     stack: Vec<(
         RoaringBitmap,
         std::iter::Take<
@@ -91,9 +92,9 @@ impl<'t, 'e> Iterator for AscendingFacetSort<'t, 'e> {
                     }
                     let starting_key_below =
                         FacetGroupKey { field_id: self.field_id, level: level - 1, left_bound };
-                    let iter = match self.db.range(&self.rtxn, &(starting_key_below..)) {
+                    let iter = match self.db.range(self.rtxn, &(starting_key_below..)) {
                         Ok(iter) => iter,
-                        Err(e) => return Some(Err(e.into())),
+                        Err(e) => return Some(Err(e)),
                     }
                     .take(group_size as usize);
 
diff --git a/milli/src/search/facet/facet_sort_descending.rs b/milli/src/search/facet/facet_sort_descending.rs
index 5f09d708b..6f073b62a 100644
--- a/milli/src/search/facet/facet_sort_descending.rs
+++ b/milli/src/search/facet/facet_sort_descending.rs
@@ -39,6 +39,7 @@ struct DescendingFacetSort<'t> {
     rtxn: &'t heed::RoTxn<'t>,
     db: heed::Database<FacetGroupKeyCodec<ByteSliceRefCodec>, FacetGroupValueCodec>,
     field_id: u16,
+    #[allow(clippy::type_complexity)]
     stack: Vec<(
         RoaringBitmap,
         std::iter::Take<
@@ -54,7 +55,7 @@ impl<'t> Iterator for DescendingFacetSort<'t> {
     fn next(&mut self) -> Option<Self::Item> {
         'outer: loop {
             let (documents_ids, deepest_iter, right_bound) = self.stack.last_mut()?;
-            while let Some(result) = deepest_iter.next() {
+            for result in deepest_iter.by_ref() {
                 let (
                     FacetGroupKey { level, left_bound, field_id },
                     FacetGroupValue { size: group_size, mut bitmap },
@@ -100,11 +101,11 @@ impl<'t> Iterator for DescendingFacetSort<'t> {
                         .db
                         .remap_key_type::<FacetGroupKeyCodec<ByteSliceRefCodec>>()
                         .rev_range(
-                            &self.rtxn,
+                            self.rtxn,
                             &(Bound::Included(starting_key_below), end_key_kelow),
                         ) {
                         Ok(iter) => iter,
-                        Err(e) => return Some(Err(e.into())),
+                        Err(e) => return Some(Err(e)),
                     }
                     .take(group_size as usize);
 
diff --git a/milli/src/search/facet/mod.rs b/milli/src/search/facet/mod.rs
index ccf40d6aa..7dfdcdb94 100644
--- a/milli/src/search/facet/mod.rs
+++ b/milli/src/search/facet/mod.rs
@@ -73,7 +73,7 @@ pub(crate) fn get_highest_level<'t>(
     let field_id_prefix = &field_id.to_be_bytes();
     Ok(db
         .as_polymorph()
-        .rev_prefix_iter::<_, ByteSlice, DecodeIgnore>(&txn, field_id_prefix)?
+        .rev_prefix_iter::<_, ByteSlice, DecodeIgnore>(txn, field_id_prefix)?
         .next()
         .map(|el| {
             let (key, _) = el.unwrap();
@@ -105,12 +105,9 @@ pub(crate) mod tests {
     pub fn get_random_looking_index() -> FacetIndex<OrderedF64Codec> {
         let index = FacetIndex::<OrderedF64Codec>::new(4, 8, 5);
         let mut txn = index.env.write_txn().unwrap();
-
         let mut rng = rand::rngs::SmallRng::from_seed([0; 32]);
-        let keys =
-            std::iter::from_fn(|| Some(rng.gen_range(0..256))).take(128).collect::<Vec<u32>>();
 
-        for (_i, key) in keys.into_iter().enumerate() {
+        for (_i, key) in std::iter::from_fn(|| Some(rng.gen_range(0..256))).take(128).enumerate() {
             let mut bitmap = RoaringBitmap::new();
             bitmap.insert(key);
             bitmap.insert(key + 100);
diff --git a/milli/src/update/delete_documents.rs b/milli/src/update/delete_documents.rs
index 1dd3f423b..a6a4ea609 100644
--- a/milli/src/update/delete_documents.rs
+++ b/milli/src/update/delete_documents.rs
@@ -138,7 +138,7 @@ impl<'t, 'u, 'i> DeleteDocuments<'t, 'u, 'i> {
         // the `soft_deleted_documents_ids` bitmap and early exit.
         let size_used = self.index.used_size()?;
         let map_size = self.index.env.map_size()? as u64;
-        let nb_documents = self.index.number_of_documents(&self.wtxn)?;
+        let nb_documents = self.index.number_of_documents(self.wtxn)?;
         let nb_soft_deleted = soft_deleted_docids.len();
 
         let percentage_available = 100 - (size_used * 100 / map_size);
@@ -474,7 +474,7 @@ impl<'t, 'u, 'i> DeleteDocuments<'t, 'u, 'i> {
                 self.index.put_faceted_documents_ids(self.wtxn, field_id, facet_type, &docids)?;
 
                 let facet_values = remove_docids_from_field_id_docid_facet_value(
-                    &self.index,
+                    self.index,
                     self.wtxn,
                     facet_type,
                     field_id,
diff --git a/milli/src/update/facet/bulk.rs b/milli/src/update/facet/bulk.rs
index ea0a7d3d7..2a4c7f49a 100644
--- a/milli/src/update/facet/bulk.rs
+++ b/milli/src/update/facet/bulk.rs
@@ -111,7 +111,7 @@ impl<R: std::io::Read + std::io::Seek> FacetsUpdateBulkInner<R> {
         }
 
         for &field_id in field_ids.iter() {
-            let (level_readers, all_docids) = self.compute_levels_for_field_id(field_id, &wtxn)?;
+            let (level_readers, all_docids) = self.compute_levels_for_field_id(field_id, wtxn)?;
 
             handle_all_docids(wtxn, field_id, all_docids)?;
 
@@ -341,7 +341,7 @@ impl<R: std::io::Read + std::io::Seek> FacetsUpdateBulkInner<R> {
                 handle_group(&bitmaps, left_bounds.first().unwrap())?;
             }
         }
-        return Ok(sub_writers);
+        Ok(sub_writers)
     }
 }
 
diff --git a/milli/src/update/facet/delete.rs b/milli/src/update/facet/delete.rs
index 2bc54c7c1..9bec2d911 100644
--- a/milli/src/update/facet/delete.rs
+++ b/milli/src/update/facet/delete.rs
@@ -100,7 +100,7 @@ impl<'i, 'b> FacetsDelete<'i, 'b> {
                     max_group_size: self.max_group_size,
                 };
                 for facet_value in affected_facet_values {
-                    inc.delete(wtxn, field_id, facet_value.as_slice(), &self.docids_to_delete)?;
+                    inc.delete(wtxn, field_id, facet_value.as_slice(), self.docids_to_delete)?;
                 }
             }
         }
diff --git a/milli/src/update/facet/incremental.rs b/milli/src/update/facet/incremental.rs
index 2558c81a3..04d702987 100644
--- a/milli/src/update/facet/incremental.rs
+++ b/milli/src/update/facet/incremental.rs
@@ -127,7 +127,7 @@ impl FacetsUpdateIncrementalInner {
         if let Some(e) = prefix_iter.next() {
             let (key_bytes, value) = e?;
             Ok((
-                FacetGroupKeyCodec::<ByteSliceRefCodec>::bytes_decode(&key_bytes)
+                FacetGroupKeyCodec::<ByteSliceRefCodec>::bytes_decode(key_bytes)
                     .ok_or(Error::Encoding)?
                     .into_owned(),
                 value,
@@ -146,11 +146,11 @@ impl FacetsUpdateIncrementalInner {
                             .as_polymorph()
                             .prefix_iter::<_, ByteSlice, FacetGroupValueCodec>(
                                 txn,
-                                &prefix.as_slice(),
+                                prefix.as_slice(),
                             )?;
                         let (key_bytes, value) = iter.next().unwrap()?;
                         Ok((
-                            FacetGroupKeyCodec::<ByteSliceRefCodec>::bytes_decode(&key_bytes)
+                            FacetGroupKeyCodec::<ByteSliceRefCodec>::bytes_decode(key_bytes)
                                 .ok_or(Error::Encoding)?
                                 .into_owned(),
                             value,
@@ -185,15 +185,15 @@ impl FacetsUpdateIncrementalInner {
         let mut iter = self
             .db
             .as_polymorph()
-            .prefix_iter::<_, ByteSlice, DecodeIgnore>(&txn, &level0_prefix)?;
+            .prefix_iter::<_, ByteSlice, DecodeIgnore>(txn, &level0_prefix)?;
 
         if iter.next().is_none() {
             drop(iter);
             self.db.put(txn, &key, &value)?;
-            return Ok(InsertionResult::Insert);
+            Ok(InsertionResult::Insert)
         } else {
             drop(iter);
-            let old_value = self.db.get(&txn, &key)?;
+            let old_value = self.db.get(txn, &key)?;
             match old_value {
                 Some(mut updated_value) => {
                     // now merge the two
@@ -236,7 +236,7 @@ impl FacetsUpdateIncrementalInner {
 
         let max_group_size = self.max_group_size;
 
-        let result = self.insert_in_level(txn, field_id, level - 1, facet_value.clone(), docids)?;
+        let result = self.insert_in_level(txn, field_id, level - 1, &(*facet_value), docids)?;
         // level below inserted an element
 
         let (insertion_key, insertion_value) =
@@ -312,13 +312,13 @@ impl FacetsUpdateIncrementalInner {
         };
 
         let mut iter =
-            self.db.range(&txn, &(start_key..))?.take((size_left as usize) + (size_right as usize));
+            self.db.range(txn, &(start_key..))?.take((size_left as usize) + (size_right as usize));
 
         let group_left = {
             let mut values_left = RoaringBitmap::new();
 
             let mut i = 0;
-            while let Some(next) = iter.next() {
+            for next in iter.by_ref() {
                 let (_key, value) = next?;
                 i += 1;
                 values_left |= &value.bitmap;
@@ -339,7 +339,7 @@ impl FacetsUpdateIncrementalInner {
                 FacetGroupValue { bitmap: mut values_right, .. },
             ) = iter.next().unwrap()?;
 
-            while let Some(next) = iter.next() {
+            for next in iter.by_ref() {
                 let (_, value) = next?;
                 values_right |= &value.bitmap;
             }
@@ -359,7 +359,7 @@ impl FacetsUpdateIncrementalInner {
     }
 
     /// Insert the given facet value and corresponding document ids in the database.
-    pub fn insert<'a, 't>(
+    pub fn insert<'t>(
         &self,
         txn: &'t mut RwTxn,
         field_id: u16,
@@ -371,7 +371,7 @@ impl FacetsUpdateIncrementalInner {
         }
         let group_size = self.group_size;
 
-        let highest_level = get_highest_level(&txn, self.db, field_id)?;
+        let highest_level = get_highest_level(txn, self.db, field_id)?;
 
         let result =
             self.insert_in_level(txn, field_id, highest_level as u8, facet_value, docids)?;
@@ -391,7 +391,7 @@ impl FacetsUpdateIncrementalInner {
         let size_highest_level = self
             .db
             .as_polymorph()
-            .prefix_iter::<_, ByteSlice, ByteSlice>(&txn, &highest_level_prefix)?
+            .prefix_iter::<_, ByteSlice, ByteSlice>(txn, &highest_level_prefix)?
             .count();
 
         if size_highest_level < self.group_size as usize * self.min_level_size as usize {
@@ -401,7 +401,7 @@ impl FacetsUpdateIncrementalInner {
         let mut groups_iter = self
             .db
             .as_polymorph()
-            .prefix_iter::<_, ByteSlice, FacetGroupValueCodec>(&txn, &highest_level_prefix)?;
+            .prefix_iter::<_, ByteSlice, FacetGroupValueCodec>(txn, &highest_level_prefix)?;
 
         let nbr_new_groups = size_highest_level / self.group_size as usize;
         let nbr_leftover_elements = size_highest_level % self.group_size as usize;
@@ -412,7 +412,7 @@ impl FacetsUpdateIncrementalInner {
             let mut values = RoaringBitmap::new();
             for _ in 0..group_size {
                 let (key_bytes, value_i) = groups_iter.next().unwrap()?;
-                let key_i = FacetGroupKeyCodec::<ByteSliceRefCodec>::bytes_decode(&key_bytes)
+                let key_i = FacetGroupKeyCodec::<ByteSliceRefCodec>::bytes_decode(key_bytes)
                     .ok_or(Error::Encoding)?;
 
                 if first_key.is_none() {
@@ -435,7 +435,7 @@ impl FacetsUpdateIncrementalInner {
             let mut values = RoaringBitmap::new();
             for _ in 0..nbr_leftover_elements {
                 let (key_bytes, value_i) = groups_iter.next().unwrap()?;
-                let key_i = FacetGroupKeyCodec::<ByteSliceRefCodec>::bytes_decode(&key_bytes)
+                let key_i = FacetGroupKeyCodec::<ByteSliceRefCodec>::bytes_decode(key_bytes)
                     .ok_or(Error::Encoding)?;
 
                 if first_key.is_none() {
@@ -494,7 +494,7 @@ impl FacetsUpdateIncrementalInner {
         let (deletion_key, mut bitmap) =
             self.find_insertion_key_value(field_id, level, facet_value, txn)?;
 
-        let result = self.delete_in_level(txn, field_id, level - 1, facet_value.clone(), docids)?;
+        let result = self.delete_in_level(txn, field_id, level - 1, &(*facet_value), docids)?;
 
         let mut decrease_size = false;
         let next_key = match result {
@@ -547,13 +547,13 @@ impl FacetsUpdateIncrementalInner {
         docids: &RoaringBitmap,
     ) -> Result<DeletionResult> {
         let key = FacetGroupKey { field_id, level: 0, left_bound: facet_value };
-        let mut bitmap = self.db.get(&txn, &key)?.unwrap().bitmap;
+        let mut bitmap = self.db.get(txn, &key)?.unwrap().bitmap;
         bitmap -= docids;
 
         if bitmap.is_empty() {
             let mut next_key = None;
             if let Some((next, _)) =
-                self.db.remap_data_type::<DecodeIgnore>().get_greater_than(&txn, &key)?
+                self.db.remap_data_type::<DecodeIgnore>().get_greater_than(txn, &key)?
             {
                 if next.field_id == field_id && next.level == 0 {
                     next_key = Some(next.left_bound.to_vec());
@@ -567,7 +567,7 @@ impl FacetsUpdateIncrementalInner {
         }
     }
 
-    pub fn delete<'a, 't>(
+    pub fn delete<'t>(
         &self,
         txn: &'t mut RwTxn,
         field_id: u16,
@@ -582,7 +582,7 @@ impl FacetsUpdateIncrementalInner {
         {
             return Ok(());
         }
-        let highest_level = get_highest_level(&txn, self.db, field_id)?;
+        let highest_level = get_highest_level(txn, self.db, field_id)?;
 
         let result =
             self.delete_in_level(txn, field_id, highest_level as u8, facet_value, docids)?;
@@ -603,7 +603,7 @@ impl FacetsUpdateIncrementalInner {
             || self
                 .db
                 .as_polymorph()
-                .prefix_iter::<_, ByteSlice, ByteSlice>(&txn, &highest_level_prefix)?
+                .prefix_iter::<_, ByteSlice, ByteSlice>(txn, &highest_level_prefix)?
                 .count()
                 >= self.min_level_size as usize
         {
@@ -614,7 +614,7 @@ impl FacetsUpdateIncrementalInner {
             .db
             .as_polymorph()
             .prefix_iter::<_, ByteSlice, ByteSlice>(txn, &highest_level_prefix)?;
-        while let Some(el) = iter.next() {
+        for el in iter.by_ref() {
             let (k, _) = el?;
             to_delete.push(
                 FacetGroupKeyCodec::<ByteSliceRefCodec>::bytes_decode(k)
@@ -640,7 +640,7 @@ impl<'a> FacetGroupKey<&'a [u8]> {
     }
 }
 
-impl<'a> FacetGroupKey<Vec<u8>> {
+impl FacetGroupKey<Vec<u8>> {
     pub fn as_ref(&self) -> FacetGroupKey<&[u8]> {
         FacetGroupKey {
             field_id: self.field_id,
@@ -804,7 +804,7 @@ mod tests {
             let mut bitmap = RoaringBitmap::new();
             bitmap.insert(i);
             index.verify_structure_validity(&txn, 0);
-            index.insert(&mut txn, 0, &(&(i as f64)), &bitmap);
+            index.insert(&mut txn, 0, &(i as f64), &bitmap);
         }
 
         for i in (200..256).into_iter().rev() {