diff --git a/meilidb-core/src/database.rs b/meilidb-core/src/database.rs
index 3a614f708..0203e2e26 100644
--- a/meilidb-core/src/database.rs
+++ b/meilidb-core/src/database.rs
@@ -263,8 +263,6 @@ mod tests {
 
         let mut writer = env.write_txn().unwrap();
         let _update_id = index.schema_update(&mut writer, schema).unwrap();
-
-        // don't forget to commit...
         writer.commit().unwrap();
 
         let mut additions = index.documents_addition();
@@ -286,8 +284,6 @@ mod tests {
 
         let mut writer = env.write_txn().unwrap();
         let update_id = additions.finalize(&mut writer).unwrap();
-
-        // don't forget to commit...
         writer.commit().unwrap();
 
         // block until the transaction is processed
@@ -329,8 +325,6 @@ mod tests {
 
         let mut writer = env.write_txn().unwrap();
         let _update_id = index.schema_update(&mut writer, schema).unwrap();
-
-        // don't forget to commit...
         writer.commit().unwrap();
 
         let mut additions = index.documents_addition();
@@ -351,8 +345,6 @@ mod tests {
 
         let mut writer = env.write_txn().unwrap();
         let update_id = additions.finalize(&mut writer).unwrap();
-
-        // don't forget to commit...
         writer.commit().unwrap();
 
         // block until the transaction is processed
@@ -564,8 +556,6 @@ mod tests {
 
         let mut writer = env.write_txn().unwrap();
         let _update_id = index.schema_update(&mut writer, schema).unwrap();
-
-        // don't forget to commit...
         writer.commit().unwrap();
 
         let mut additions = index.documents_addition();
@@ -589,8 +579,6 @@ mod tests {
 
         let mut writer = env.write_txn().unwrap();
         let update_id = additions.finalize(&mut writer).unwrap();
-
-        // don't forget to commit...
         writer.commit().unwrap();
 
         // block until the transaction is processed
@@ -613,4 +601,136 @@ mod tests {
             .unwrap();
         assert!(document.is_some());
     }
+
+    #[test]
+    fn partial_document_update() {
+        let dir = tempfile::tempdir().unwrap();
+
+        let database = Database::open_or_create(dir.path()).unwrap();
+        let env = &database.env;
+
+        let (sender, receiver) = mpsc::sync_channel(100);
+        let update_fn = move |update: ProcessedUpdateResult| sender.send(update.update_id).unwrap();
+        let index = database.create_index("test").unwrap();
+
+        let done = database.set_update_callback("test", Box::new(update_fn));
+        assert!(done, "could not set the index update function");
+
+        let schema = {
+            let data = r#"
+                identifier = "id"
+
+                [attributes."id"]
+                displayed = true
+
+                [attributes."name"]
+                displayed = true
+                indexed = true
+
+                [attributes."description"]
+                displayed = true
+                indexed = true
+            "#;
+            toml::from_str(data).unwrap()
+        };
+
+        let mut writer = env.write_txn().unwrap();
+        let _update_id = index.schema_update(&mut writer, schema).unwrap();
+        writer.commit().unwrap();
+
+        let mut additions = index.documents_addition();
+
+        // DocumentId(7900334843754999545)
+        let doc1 = serde_json::json!({
+            "id": 123,
+            "name": "Marvin",
+            "description": "My name is Marvin",
+        });
+
+        // DocumentId(8367468610878465872)
+        let doc2 = serde_json::json!({
+            "id": 234,
+            "name": "Kevin",
+            "description": "My name is Kevin",
+        });
+
+        additions.update_document(doc1);
+        additions.update_document(doc2);
+
+        let mut writer = env.write_txn().unwrap();
+        let update_id = additions.finalize(&mut writer).unwrap();
+        writer.commit().unwrap();
+
+        // block until the transaction is processed
+        let _ = receiver.iter().find(|id| *id == update_id);
+
+        let reader = env.read_txn().unwrap();
+        let result = index.update_status(&reader, update_id).unwrap();
+        assert_matches!(result, UpdateStatus::Processed(status) if status.result.is_ok());
+
+        let document: Option<IgnoredAny> = index.document(&reader, None, DocumentId(25)).unwrap();
+        assert!(document.is_none());
+
+        let document: Option<IgnoredAny> = index
+            .document(&reader, None, DocumentId(7900334843754999545))
+            .unwrap();
+        assert!(document.is_some());
+
+        let document: Option<IgnoredAny> = index
+            .document(&reader, None, DocumentId(8367468610878465872))
+            .unwrap();
+        assert!(document.is_some());
+
+        reader.abort();
+
+        let mut partial_additions = index.documents_partial_addition();
+
+        // DocumentId(7900334843754999545)
+        let partial_doc1 = serde_json::json!({
+            "id": 123,
+            "description": "I am the new Marvin",
+        });
+
+        // DocumentId(8367468610878465872)
+        let partial_doc2 = serde_json::json!({
+            "id": 234,
+            "description": "I am the new Kevin",
+        });
+
+        partial_additions.update_document(partial_doc1);
+        partial_additions.update_document(partial_doc2);
+
+        let mut writer = env.write_txn().unwrap();
+        let update_id = partial_additions.finalize(&mut writer).unwrap();
+        writer.commit().unwrap();
+
+        // block until the transaction is processed
+        let _ = receiver.iter().find(|id| *id == update_id);
+
+        let reader = env.read_txn().unwrap();
+        let result = index.update_status(&reader, update_id).unwrap();
+        assert_matches!(result, UpdateStatus::Processed(status) if status.result.is_ok());
+
+        let document: Option<serde_json::Value> = index
+            .document(&reader, None, DocumentId(7900334843754999545))
+            .unwrap();
+
+        let new_doc1 = serde_json::json!({
+            "id": 123,
+            "name": "Marvin",
+            "description": "I am the new Marvin",
+        });
+        assert_eq!(document, Some(new_doc1));
+
+        let document: Option<serde_json::Value> = index
+            .document(&reader, None, DocumentId(8367468610878465872))
+            .unwrap();
+
+        let new_doc2 = serde_json::json!({
+            "id": 234,
+            "name": "Kevin",
+            "description": "I am the new Kevin",
+        });
+        assert_eq!(document, Some(new_doc2));
+    }
 }
diff --git a/meilidb-core/src/store/mod.rs b/meilidb-core/src/store/mod.rs
index ed2a5e328..f53900a79 100644
--- a/meilidb-core/src/store/mod.rs
+++ b/meilidb-core/src/store/mod.rs
@@ -156,6 +156,14 @@ impl Index {
         )
     }
 
+    pub fn documents_partial_addition<D>(&self) -> update::DocumentsAddition<D> {
+        update::DocumentsAddition::new_partial(
+            self.updates,
+            self.updates_results,
+            self.updates_notifier.clone(),
+        )
+    }
+
     pub fn documents_deletion(&self) -> update::DocumentsDeletion {
         update::DocumentsDeletion::new(
             self.updates,
diff --git a/meilidb-core/src/update/documents_addition.rs b/meilidb-core/src/update/documents_addition.rs
index 8aa5468d7..7a7f03362 100644
--- a/meilidb-core/src/update/documents_addition.rs
+++ b/meilidb-core/src/update/documents_addition.rs
@@ -2,10 +2,10 @@ use std::collections::HashMap;
 
 use fst::{set::OpBuilder, SetBuilder};
 use sdset::{duo::Union, SetOperation};
-use serde::Serialize;
+use serde::{Deserialize, Serialize};
 
 use crate::raw_indexer::RawIndexer;
-use crate::serde::{extract_document_id, serialize_value, Serializer};
+use crate::serde::{extract_document_id, serialize_value, Deserializer, Serializer};
 use crate::store;
 use crate::update::{apply_documents_deletion, next_update_id, Update};
 use crate::{Error, MResult, RankedMap};
@@ -15,6 +15,7 @@ pub struct DocumentsAddition<D> {
     updates_results_store: store::UpdatesResults,
     updates_notifier: crossbeam_channel::Sender<()>,
     documents: Vec<D>,
+    is_partial: bool,
 }
 
 impl<D> DocumentsAddition<D> {
@@ -28,6 +29,21 @@ impl<D> DocumentsAddition<D> {
             updates_results_store,
             updates_notifier,
             documents: Vec::new(),
+            is_partial: false,
+        }
+    }
+
+    pub fn new_partial(
+        updates_store: store::Updates,
+        updates_results_store: store::UpdatesResults,
+        updates_notifier: crossbeam_channel::Sender<()>,
+    ) -> DocumentsAddition<D> {
+        DocumentsAddition {
+            updates_store,
+            updates_results_store,
+            updates_notifier,
+            documents: Vec::new(),
+            is_partial: true,
         }
     }
 
@@ -45,6 +61,7 @@ impl<D> DocumentsAddition<D> {
             self.updates_store,
             self.updates_results_store,
             self.documents,
+            self.is_partial,
         )?;
         Ok(update_id)
     }
@@ -61,6 +78,7 @@ pub fn push_documents_addition<D: serde::Serialize>(
     updates_store: store::Updates,
     updates_results_store: store::UpdatesResults,
     addition: Vec<D>,
+    is_partial: bool,
 ) -> MResult<u64> {
     let mut values = Vec::with_capacity(addition.len());
     for add in addition {
@@ -71,7 +89,12 @@ pub fn push_documents_addition<D: serde::Serialize>(
 
     let last_update_id = next_update_id(writer, updates_store, updates_results_store)?;
 
-    let update = Update::DocumentsAddition(values);
+    let update = if is_partial {
+        Update::DocumentsPartial(values)
+    } else {
+        Update::DocumentsAddition(values)
+    };
+
     updates_store.put_update(writer, last_update_id, &update)?;
 
     Ok(last_update_id)
@@ -84,7 +107,7 @@ pub fn apply_documents_addition<'a, 'b>(
     documents_fields_counts_store: store::DocumentsFieldsCounts,
     postings_lists_store: store::PostingsLists,
     docs_words_store: store::DocsWords,
-    addition: Vec<serde_json::Value>,
+    addition: Vec<HashMap<String, serde_json::Value>>,
 ) -> MResult<()> {
     let mut documents_additions = HashMap::new();
 
@@ -156,6 +179,102 @@ pub fn apply_documents_addition<'a, 'b>(
     )
 }
 
+pub fn apply_documents_partial_addition<'a, 'b>(
+    writer: &'a mut heed::RwTxn<'b>,
+    main_store: store::Main,
+    documents_fields_store: store::DocumentsFields,
+    documents_fields_counts_store: store::DocumentsFieldsCounts,
+    postings_lists_store: store::PostingsLists,
+    docs_words_store: store::DocsWords,
+    addition: Vec<HashMap<String, serde_json::Value>>,
+) -> MResult<()> {
+    let mut documents_additions = HashMap::new();
+
+    let schema = match main_store.schema(writer)? {
+        Some(schema) => schema,
+        None => return Err(Error::SchemaMissing),
+    };
+
+    let identifier = schema.identifier_name();
+
+    // 1. store documents ids for future deletion
+    for mut document in addition {
+        let document_id = match extract_document_id(identifier, &document)? {
+            Some(id) => id,
+            None => return Err(Error::MissingDocumentId),
+        };
+
+        let mut deserializer = Deserializer {
+            document_id,
+            reader: writer,
+            documents_fields: documents_fields_store,
+            schema: &schema,
+            attributes: None,
+        };
+
+        // retrieve the old document and
+        // update the new one with missing keys found in the old one
+        let result = Option::<HashMap<String, serde_json::Value>>::deserialize(&mut deserializer)?;
+        if let Some(old_document) = result {
+            for (key, value) in old_document {
+                document.entry(key).or_insert(value);
+            }
+        }
+
+        documents_additions.insert(document_id, document);
+    }
+
+    // 2. remove the documents posting lists
+    let number_of_inserted_documents = documents_additions.len();
+    let documents_ids = documents_additions.iter().map(|(id, _)| *id).collect();
+    apply_documents_deletion(
+        writer,
+        main_store,
+        documents_fields_store,
+        documents_fields_counts_store,
+        postings_lists_store,
+        docs_words_store,
+        documents_ids,
+    )?;
+
+    let mut ranked_map = match main_store.ranked_map(writer)? {
+        Some(ranked_map) => ranked_map,
+        None => RankedMap::default(),
+    };
+
+    let stop_words = match main_store.stop_words_fst(writer)? {
+        Some(stop_words) => stop_words,
+        None => fst::Set::default(),
+    };
+
+    // 3. index the documents fields in the stores
+    let mut indexer = RawIndexer::new(stop_words);
+
+    for (document_id, document) in documents_additions {
+        let serializer = Serializer {
+            txn: writer,
+            schema: &schema,
+            document_store: documents_fields_store,
+            document_fields_counts: documents_fields_counts_store,
+            indexer: &mut indexer,
+            ranked_map: &mut ranked_map,
+            document_id,
+        };
+
+        document.serialize(serializer)?;
+    }
+
+    write_documents_addition_index(
+        writer,
+        main_store,
+        postings_lists_store,
+        docs_words_store,
+        &ranked_map,
+        number_of_inserted_documents,
+        indexer,
+    )
+}
+
 pub fn reindex_all_documents(
     writer: &mut heed::RwTxn,
     main_store: store::Main,
diff --git a/meilidb-core/src/update/mod.rs b/meilidb-core/src/update/mod.rs
index 52d8ab3d5..8d00498f0 100644
--- a/meilidb-core/src/update/mod.rs
+++ b/meilidb-core/src/update/mod.rs
@@ -10,7 +10,9 @@ mod synonyms_deletion;
 
 pub use self::clear_all::{apply_clear_all, push_clear_all};
 pub use self::customs_update::{apply_customs_update, push_customs_update};
-pub use self::documents_addition::{apply_documents_addition, DocumentsAddition};
+pub use self::documents_addition::{
+    apply_documents_addition, apply_documents_partial_addition, DocumentsAddition,
+};
 pub use self::documents_deletion::{apply_documents_deletion, DocumentsDeletion};
 pub use self::schema_update::{apply_schema_update, push_schema_update};
 pub use self::stop_words_addition::{apply_stop_words_addition, StopWordsAddition};
@@ -19,7 +21,7 @@ pub use self::synonyms_addition::{apply_synonyms_addition, SynonymsAddition};
 pub use self::synonyms_deletion::{apply_synonyms_deletion, SynonymsDeletion};
 
 use std::cmp;
-use std::collections::{BTreeMap, BTreeSet};
+use std::collections::{BTreeMap, BTreeSet, HashMap};
 use std::time::{Duration, Instant};
 
 use heed::Result as ZResult;
@@ -34,7 +36,8 @@ pub enum Update {
     ClearAll,
     Schema(Schema),
     Customs(Vec<u8>),
-    DocumentsAddition(Vec<serde_json::Value>),
+    DocumentsAddition(Vec<HashMap<String, serde_json::Value>>),
+    DocumentsPartial(Vec<HashMap<String, serde_json::Value>>),
     DocumentsDeletion(Vec<DocumentId>),
     SynonymsAddition(BTreeMap<String, Vec<String>>),
     SynonymsDeletion(BTreeMap<String, Option<Vec<String>>>),
@@ -53,6 +56,9 @@ impl Update {
             Update::DocumentsAddition(addition) => UpdateType::DocumentsAddition {
                 number: addition.len(),
             },
+            Update::DocumentsPartial(addition) => UpdateType::DocumentsPartial {
+                number: addition.len(),
+            },
             Update::DocumentsDeletion(deletion) => UpdateType::DocumentsDeletion {
                 number: deletion.len(),
             },
@@ -78,6 +84,7 @@ pub enum UpdateType {
     Schema { schema: Schema },
     Customs,
     DocumentsAddition { number: usize },
+    DocumentsPartial { number: usize },
     DocumentsDeletion { number: usize },
     SynonymsAddition { number: usize },
     SynonymsDeletion { number: usize },
@@ -218,6 +225,25 @@ pub fn update_task<'a, 'b>(
 
             (update_type, result, start.elapsed())
         }
+        Update::DocumentsPartial(documents) => {
+            let start = Instant::now();
+
+            let update_type = UpdateType::DocumentsPartial {
+                number: documents.len(),
+            };
+
+            let result = apply_documents_partial_addition(
+                writer,
+                index.main,
+                index.documents_fields,
+                index.documents_fields_counts,
+                index.postings_lists,
+                index.docs_words,
+                documents,
+            );
+
+            (update_type, result, start.elapsed())
+        }
         Update::DocumentsDeletion(documents) => {
             let start = Instant::now();