diff --git a/examples/create-database.rs b/examples/create-database.rs
index 89e96014b..e1f1cb0b5 100644
--- a/examples/create-database.rs
+++ b/examples/create-database.rs
@@ -5,7 +5,7 @@ use serde_derive::{Serialize, Deserialize};
 use structopt::StructOpt;
 
 use meilidb::database::schema::{Schema, SchemaBuilder, STORED, INDEXED};
-use meilidb::database::update::PositiveUpdateBuilder;
+use meilidb::database::PositiveUpdateBuilder;
 use meilidb::tokenizer::DefaultBuilder;
 use meilidb::database::Database;
 
diff --git a/src/database/database.rs b/src/database/database.rs
new file mode 100644
index 000000000..5db8d3ac7
--- /dev/null
+++ b/src/database/database.rs
@@ -0,0 +1,233 @@
+use std::sync::{Arc, Mutex, RwLock, RwLockReadGuard};
+use std::error::Error;
+use std::path::Path;
+
+use rocksdb::rocksdb_options::{DBOptions, IngestExternalFileOptions, ColumnFamilyOptions};
+use rocksdb::rocksdb::{Writable, Snapshot};
+use rocksdb::{DB, DBVector, MergeOperands};
+
+use crate::database::{DatabaseView, Update, Schema};
+use crate::database::{DATA_INDEX, DATA_SCHEMA};
+use crate::database::blob::{self, Blob};
+
+pub struct Database {
+    // DB is under a Mutex to sync update ingestions and separate DB update locking
+    // and DatabaseView acquiring locking in other words:
+    // "Block readers the minimum possible amount of time"
+    db: Mutex<Arc<DB>>,
+
+    // This view is updated each time the DB ingests an update
+    view: RwLock<DatabaseView<Arc<DB>>>,
+}
+
+impl Database {
+    pub fn create<P: AsRef<Path>>(path: P, schema: Schema) -> Result<Database, Box<Error>> {
+        let path = path.as_ref();
+        if path.exists() {
+            return Err(format!("File already exists at path: {}, cannot create database.",
+                                path.display()).into())
+        }
+
+        let path = path.to_string_lossy();
+        let mut opts = DBOptions::new();
+        opts.create_if_missing(true);
+        // opts.error_if_exists(true); // FIXME pull request that
+
+        let mut cf_opts = ColumnFamilyOptions::new();
+        cf_opts.add_merge_operator("data-index merge operator", merge_indexes);
+
+        let db = DB::open_cf(opts, &path, vec![("default", cf_opts)])?;
+
+        let mut schema_bytes = Vec::new();
+        schema.write_to(&mut schema_bytes)?;
+        db.put(DATA_SCHEMA, &schema_bytes)?;
+
+        let db = Arc::new(db);
+        let snapshot = Snapshot::new(db.clone());
+        let view = RwLock::new(DatabaseView::new(snapshot)?);
+
+        Ok(Database { db: Mutex::new(db), view })
+    }
+
+    pub fn open<P: AsRef<Path>>(path: P) -> Result<Database, Box<Error>> {
+        let path = path.as_ref().to_string_lossy();
+
+        let mut opts = DBOptions::new();
+        opts.create_if_missing(false);
+
+        let mut cf_opts = ColumnFamilyOptions::new();
+        cf_opts.add_merge_operator("data-index merge operator", merge_indexes);
+
+        let db = DB::open_cf(opts, &path, vec![("default", cf_opts)])?;
+
+        // FIXME create a generic function to do that !
+        let _schema = match db.get(DATA_SCHEMA)? {
+            Some(value) => Schema::read_from(&*value)?,
+            None => return Err(String::from("Database does not contain a schema").into()),
+        };
+
+        let db = Arc::new(db);
+        let snapshot = Snapshot::new(db.clone());
+        let view = RwLock::new(DatabaseView::new(snapshot)?);
+
+        Ok(Database { db: Mutex::new(db), view })
+    }
+
+    pub fn ingest_update_file(&self, update: Update) -> Result<(), Box<Error>> {
+        let snapshot = {
+            // We must have a mutex here to ensure that update ingestions and compactions
+            // are done atomatically and in the right order.
+            // This way update ingestions will block other update ingestions without blocking view
+            // creations while doing the "data-index" compaction
+            let db = match self.db.lock() {
+                Ok(db) => db,
+                Err(e) => return Err(e.to_string().into()),
+            };
+
+            let move_update = update.can_be_moved();
+            let path = update.into_path_buf();
+            let path = path.to_string_lossy();
+
+            let mut options = IngestExternalFileOptions::new();
+            options.move_files(move_update);
+
+            let cf_handle = db.cf_handle("default").expect("\"default\" column family not found");
+            db.ingest_external_file_optimized(&cf_handle, &options, &[&path])?;
+
+            // Compacting to trigger the merge operator only one time
+            // while ingesting the update and not each time searching
+            db.compact_range(Some(DATA_INDEX), Some(DATA_INDEX));
+
+            Snapshot::new(db.clone())
+        };
+
+        // Here we will block the view creation for the minimum amount of time:
+        // updating the DatabaseView itself with the new database snapshot
+        let view = DatabaseView::new(snapshot)?;
+        match self.view.write() {
+            Ok(mut lock) => *lock = view,
+            Err(e) => return Err(e.to_string().into()),
+        }
+
+        Ok(())
+    }
+
+    pub fn get(&self, key: &[u8]) -> Result<Option<DBVector>, Box<Error>> {
+        self.view().get(key)
+    }
+
+    pub fn flush(&self) -> Result<(), Box<Error>> {
+        match self.db.lock() {
+            Ok(db) => Ok(db.flush(true)?),
+            Err(e) => Err(e.to_string().into()),
+        }
+    }
+
+    pub fn view(&self) -> RwLockReadGuard<DatabaseView<Arc<DB>>> {
+        self.view.read().unwrap()
+    }
+}
+
+fn merge_indexes(key: &[u8], existing_value: Option<&[u8]>, operands: &mut MergeOperands) -> Vec<u8> {
+    if key != DATA_INDEX {
+        panic!("The merge operator only supports \"data-index\" merging")
+    }
+
+    let capacity = {
+        let remaining = operands.size_hint().0;
+        let already_exist = usize::from(existing_value.is_some());
+        remaining + already_exist
+    };
+
+    let mut op = blob::OpBuilder::with_capacity(capacity);
+    if let Some(existing_value) = existing_value {
+        let blob = bincode::deserialize(existing_value).expect("BUG: could not deserialize data-index");
+        op.push(Blob::Positive(blob));
+    }
+
+    for bytes in operands {
+        let blob = bincode::deserialize(bytes).expect("BUG: could not deserialize blob");
+        op.push(blob);
+    }
+
+    let blob = op.merge().expect("BUG: could not merge blobs");
+    bincode::serialize(&blob).expect("BUG: could not serialize merged blob")
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+    use std::error::Error;
+
+    use serde_derive::{Serialize, Deserialize};
+    use tempfile::tempdir;
+
+    use crate::tokenizer::DefaultBuilder;
+    use crate::database::update::PositiveUpdateBuilder;
+    use crate::database::schema::{SchemaBuilder, STORED, INDEXED};
+
+    #[test]
+    fn ingest_update_file() -> Result<(), Box<Error>> {
+        let dir = tempdir()?;
+
+        let rocksdb_path = dir.path().join("rocksdb.rdb");
+
+        #[derive(Serialize, Deserialize, Debug, Clone, PartialEq, Eq)]
+        struct SimpleDoc {
+            id: u64,
+            title: String,
+            description: String,
+            timestamp: u64,
+        }
+
+        let schema = {
+            let mut builder = SchemaBuilder::with_identifier("id");
+            builder.new_attribute("id", STORED);
+            builder.new_attribute("title", STORED | INDEXED);
+            builder.new_attribute("description", STORED | INDEXED);
+            builder.new_attribute("timestamp", STORED);
+            builder.build()
+        };
+
+        let database = Database::create(&rocksdb_path, schema.clone())?;
+        let tokenizer_builder = DefaultBuilder::new();
+
+        let update_path = dir.path().join("update.sst");
+
+        let doc0 = SimpleDoc {
+            id: 0,
+            title: String::from("I am a title"),
+            description: String::from("I am a description"),
+            timestamp: 1234567,
+        };
+        let doc1 = SimpleDoc {
+            id: 1,
+            title: String::from("I am the second title"),
+            description: String::from("I am the second description"),
+            timestamp: 7654321,
+        };
+
+        let docid0;
+        let docid1;
+        let mut update = {
+            let mut builder = PositiveUpdateBuilder::new(update_path, schema, tokenizer_builder);
+
+            docid0 = builder.update(&doc0).unwrap();
+            docid1 = builder.update(&doc1).unwrap();
+
+            builder.build()?
+        };
+
+        update.set_move(true);
+        database.ingest_update_file(update)?;
+        let view = database.view();
+
+        let de_doc0: SimpleDoc = view.document_by_id(docid0)?;
+        let de_doc1: SimpleDoc = view.document_by_id(docid1)?;
+
+        assert_eq!(doc0, de_doc0);
+        assert_eq!(doc1, de_doc1);
+
+        Ok(dir.close()?)
+    }
+}
diff --git a/src/database/mod.rs b/src/database/mod.rs
index 245ec3db6..f3361ee35 100644
--- a/src/database/mod.rs
+++ b/src/database/mod.rs
@@ -1,20 +1,22 @@
-use std::sync::{Arc, Mutex, RwLock, RwLockReadGuard};
 use std::collections::hash_map::DefaultHasher;
 use std::hash::{Hash, Hasher};
 use std::error::Error;
-use std::path::Path;
 use std::ops::Deref;
 
-use rocksdb::rocksdb_options::{DBOptions, IngestExternalFileOptions, ColumnFamilyOptions};
-use rocksdb::rocksdb::{Writable, Snapshot};
-use rocksdb::{DB, DBVector, MergeOperands};
+use rocksdb::rocksdb::{DB, Snapshot};
 
+pub use self::update::{
+    Update, PositiveUpdateBuilder, NewState,
+    SerializerError, NegativeUpdateBuilder
+};
 pub use self::document_key::{DocumentKey, DocumentKeyAttr};
 pub use self::database_view::{DatabaseView, DocumentIter};
+pub use self::database::Database;
+pub use self::schema::Schema;
 use self::blob::positive::PositiveBlob;
-use self::update::Update;
-use self::schema::Schema;
-use self::blob::Blob;
+
+const DATA_INDEX:  &[u8] = b"data-index";
+const DATA_SCHEMA: &[u8] = b"data-schema";
 
 macro_rules! forward_to_unserializable_type {
     ($($ty:ident => $se_method:ident,)*) => {
@@ -28,21 +30,19 @@ macro_rules! forward_to_unserializable_type {
 
 pub mod blob;
 pub mod schema;
-pub mod update;
+mod update;
+mod database;
 mod document_key;
 mod database_view;
 mod deserializer;
 
-const DATA_INDEX:  &[u8] = b"data-index";
-const DATA_SCHEMA: &[u8] = b"data-schema";
-
 fn calculate_hash<T: Hash>(t: &T) -> u64 {
     let mut s = DefaultHasher::new();
     t.hash(&mut s);
     s.finish()
 }
 
-pub fn retrieve_data_schema<D>(snapshot: &Snapshot<D>) -> Result<Schema, Box<Error>>
+fn retrieve_data_schema<D>(snapshot: &Snapshot<D>) -> Result<Schema, Box<Error>>
 where D: Deref<Target=DB>
 {
     match snapshot.get(DATA_SCHEMA)? {
@@ -51,7 +51,7 @@ where D: Deref<Target=DB>
     }
 }
 
-pub fn retrieve_data_index<D>(snapshot: &Snapshot<D>) -> Result<PositiveBlob, Box<Error>>
+fn retrieve_data_index<D>(snapshot: &Snapshot<D>) -> Result<PositiveBlob, Box<Error>>
 where D: Deref<Target=DB>
 {
     match snapshot.get(DATA_INDEX)? {
@@ -59,225 +59,3 @@ where D: Deref<Target=DB>
         None => Ok(PositiveBlob::default()),
     }
 }
-
-pub struct Database {
-    // DB is under a Mutex to sync update ingestions and separate DB update locking
-    // and DatabaseView acquiring locking in other words:
-    // "Block readers the minimum possible amount of time"
-    db: Mutex<Arc<DB>>,
-
-    // This view is updated each time the DB ingests an update
-    view: RwLock<DatabaseView<Arc<DB>>>,
-}
-
-impl Database {
-    pub fn create<P: AsRef<Path>>(path: P, schema: Schema) -> Result<Database, Box<Error>> {
-        let path = path.as_ref();
-        if path.exists() {
-            return Err(format!("File already exists at path: {}, cannot create database.",
-                                path.display()).into())
-        }
-
-        let path = path.to_string_lossy();
-        let mut opts = DBOptions::new();
-        opts.create_if_missing(true);
-        // opts.error_if_exists(true); // FIXME pull request that
-
-        let mut cf_opts = ColumnFamilyOptions::new();
-        cf_opts.add_merge_operator("data-index merge operator", merge_indexes);
-
-        let db = DB::open_cf(opts, &path, vec![("default", cf_opts)])?;
-
-        let mut schema_bytes = Vec::new();
-        schema.write_to(&mut schema_bytes)?;
-        db.put(DATA_SCHEMA, &schema_bytes)?;
-
-        let db = Arc::new(db);
-        let snapshot = Snapshot::new(db.clone());
-        let view = RwLock::new(DatabaseView::new(snapshot)?);
-
-        Ok(Database { db: Mutex::new(db), view })
-    }
-
-    pub fn open<P: AsRef<Path>>(path: P) -> Result<Database, Box<Error>> {
-        let path = path.as_ref().to_string_lossy();
-
-        let mut opts = DBOptions::new();
-        opts.create_if_missing(false);
-
-        let mut cf_opts = ColumnFamilyOptions::new();
-        cf_opts.add_merge_operator("data-index merge operator", merge_indexes);
-
-        let db = DB::open_cf(opts, &path, vec![("default", cf_opts)])?;
-
-        // FIXME create a generic function to do that !
-        let _schema = match db.get(DATA_SCHEMA)? {
-            Some(value) => Schema::read_from(&*value)?,
-            None => return Err(String::from("Database does not contain a schema").into()),
-        };
-
-        let db = Arc::new(db);
-        let snapshot = Snapshot::new(db.clone());
-        let view = RwLock::new(DatabaseView::new(snapshot)?);
-
-        Ok(Database { db: Mutex::new(db), view })
-    }
-
-    pub fn ingest_update_file(&self, update: Update) -> Result<(), Box<Error>> {
-        let snapshot = {
-            // We must have a mutex here to ensure that update ingestions and compactions
-            // are done atomatically and in the right order.
-            // This way update ingestions will block other update ingestions without blocking view
-            // creations while doing the "data-index" compaction
-            let db = match self.db.lock() {
-                Ok(db) => db,
-                Err(e) => return Err(e.to_string().into()),
-            };
-
-            let move_update = update.can_be_moved();
-            let path = update.into_path_buf();
-            let path = path.to_string_lossy();
-
-            let mut options = IngestExternalFileOptions::new();
-            options.move_files(move_update);
-
-            let cf_handle = db.cf_handle("default").expect("\"default\" column family not found");
-            db.ingest_external_file_optimized(&cf_handle, &options, &[&path])?;
-
-            // Compacting to trigger the merge operator only one time
-            // while ingesting the update and not each time searching
-            db.compact_range(Some(DATA_INDEX), Some(DATA_INDEX));
-
-            Snapshot::new(db.clone())
-        };
-
-        // Here we will block the view creation for the minimum amount of time:
-        // updating the DatabaseView itself with the new database snapshot
-        let view = DatabaseView::new(snapshot)?;
-        match self.view.write() {
-            Ok(mut lock) => *lock = view,
-            Err(e) => return Err(e.to_string().into()),
-        }
-
-        Ok(())
-    }
-
-    pub fn get(&self, key: &[u8]) -> Result<Option<DBVector>, Box<Error>> {
-        self.view().get(key)
-    }
-
-    pub fn flush(&self) -> Result<(), Box<Error>> {
-        match self.db.lock() {
-            Ok(db) => Ok(db.flush(true)?),
-            Err(e) => Err(e.to_string().into()),
-        }
-    }
-
-    pub fn view(&self) -> RwLockReadGuard<DatabaseView<Arc<DB>>> {
-        self.view.read().unwrap()
-    }
-}
-
-fn merge_indexes(key: &[u8], existing_value: Option<&[u8]>, operands: &mut MergeOperands) -> Vec<u8> {
-    if key != DATA_INDEX {
-        panic!("The merge operator only supports \"data-index\" merging")
-    }
-
-    let capacity = {
-        let remaining = operands.size_hint().0;
-        let already_exist = usize::from(existing_value.is_some());
-        remaining + already_exist
-    };
-
-    let mut op = blob::OpBuilder::with_capacity(capacity);
-    if let Some(existing_value) = existing_value {
-        let blob = bincode::deserialize(existing_value).expect("BUG: could not deserialize data-index");
-        op.push(Blob::Positive(blob));
-    }
-
-    for bytes in operands {
-        let blob = bincode::deserialize(bytes).expect("BUG: could not deserialize blob");
-        op.push(blob);
-    }
-
-    let blob = op.merge().expect("BUG: could not merge blobs");
-    bincode::serialize(&blob).expect("BUG: could not serialize merged blob")
-}
-
-#[cfg(test)]
-mod tests {
-    use super::*;
-    use std::error::Error;
-
-    use serde_derive::{Serialize, Deserialize};
-    use tempfile::tempdir;
-
-    use crate::tokenizer::DefaultBuilder;
-    use crate::database::update::PositiveUpdateBuilder;
-    use crate::database::schema::{SchemaBuilder, STORED, INDEXED};
-
-    #[test]
-    fn ingest_update_file() -> Result<(), Box<Error>> {
-        let dir = tempdir()?;
-
-        let rocksdb_path = dir.path().join("rocksdb.rdb");
-
-        #[derive(Serialize, Deserialize, Debug, Clone, PartialEq, Eq)]
-        struct SimpleDoc {
-            id: u64,
-            title: String,
-            description: String,
-            timestamp: u64,
-        }
-
-        let schema = {
-            let mut builder = SchemaBuilder::with_identifier("id");
-            builder.new_attribute("id", STORED);
-            builder.new_attribute("title", STORED | INDEXED);
-            builder.new_attribute("description", STORED | INDEXED);
-            builder.new_attribute("timestamp", STORED);
-            builder.build()
-        };
-
-        let database = Database::create(&rocksdb_path, schema.clone())?;
-        let tokenizer_builder = DefaultBuilder::new();
-
-        let update_path = dir.path().join("update.sst");
-
-        let doc0 = SimpleDoc {
-            id: 0,
-            title: String::from("I am a title"),
-            description: String::from("I am a description"),
-            timestamp: 1234567,
-        };
-        let doc1 = SimpleDoc {
-            id: 1,
-            title: String::from("I am the second title"),
-            description: String::from("I am the second description"),
-            timestamp: 7654321,
-        };
-
-        let docid0;
-        let docid1;
-        let mut update = {
-            let mut builder = PositiveUpdateBuilder::new(update_path, schema, tokenizer_builder);
-
-            docid0 = builder.update(&doc0).unwrap();
-            docid1 = builder.update(&doc1).unwrap();
-
-            builder.build()?
-        };
-
-        update.set_move(true);
-        database.ingest_update_file(update)?;
-        let view = database.view();
-
-        let de_doc0: SimpleDoc = view.document_by_id(docid0)?;
-        let de_doc1: SimpleDoc = view.document_by_id(docid1)?;
-
-        assert_eq!(doc0, de_doc0);
-        assert_eq!(doc1, de_doc1);
-
-        Ok(dir.close()?)
-    }
-}