diff --git a/lib/src/sparql/error.rs b/lib/src/sparql/error.rs
index 78228204..d42693c2 100644
--- a/lib/src/sparql/error.rs
+++ b/lib/src/sparql/error.rs
@@ -19,6 +19,9 @@ pub enum EvaluationError {
     Io(io::Error),
     /// An error returned during the query evaluation itself
     Query(QueryError),
+    /// A conflict during a transaction
+    #[doc(hidden)]
+    Conflict,
 }
 
 #[derive(Debug)]
@@ -38,6 +41,7 @@ impl fmt::Display for EvaluationError {
             Self::Parsing(error) => error.fmt(f),
             Self::Io(error) => error.fmt(f),
             Self::Query(error) => error.fmt(f),
+            Self::Conflict => write!(f, "Transaction conflict"),
         }
     }
 }
@@ -57,6 +61,7 @@ impl error::Error for EvaluationError {
             Self::Parsing(e) => Some(e),
             Self::Io(e) => Some(e),
             Self::Query(e) => Some(e),
+            _ => None,
         }
     }
 }
diff --git a/lib/src/store/sled.rs b/lib/src/store/sled.rs
index a91ca7c8..812d0eb4 100644
--- a/lib/src/store/sled.rs
+++ b/lib/src/store/sled.rs
@@ -1,15 +1,21 @@
 //! Store based on the [Sled](https://sled.rs/) key-value database.
 
-use crate::error::{invalid_data_error, UnwrapInfallible};
+use crate::error::invalid_data_error;
 use crate::io::{DatasetFormat, GraphFormat};
 use crate::model::*;
 use crate::sparql::{EvaluationError, Query, QueryOptions, QueryResult, SimplePreparedQuery};
 use crate::store::numeric_encoder::*;
 use crate::store::{
-    dump_dataset, dump_graph, load_dataset, load_graph, ReadableEncodedStore, WritableEncodedStore,
+    dump_dataset, dump_graph, load_dataset, load_graph, ReadableEncodedStore, StoreOrParseError,
+    WritableEncodedStore,
 };
-use sled::{Batch, Config, Iter, Tree};
-use std::convert::{Infallible, TryInto};
+use sled::transaction::{
+    ConflictableTransactionError, TransactionError, Transactional, TransactionalTree,
+    UnabortableTransactionError,
+};
+use sled::{Config, Iter, Tree};
+use std::convert::TryInto;
+use std::error::Error;
 use std::io::{BufRead, Cursor, Write};
 use std::path::Path;
 use std::{fmt, io, str};
@@ -149,16 +155,34 @@ impl SledStore {
     /// The transaction is executed if the given closure returns `Ok`.
     /// Nothing is done if the closure returns `Err`.
     ///
-    /// See `MemoryStore` for a usage example.
-    pub fn transaction<'a, E: From<io::Error>>(
-        &'a self,
-        f: impl FnOnce(&mut SledTransaction<'a>) -> Result<(), E>,
-    ) -> Result<(), E> {
-        let mut transaction = SledTransaction {
-            inner: BatchWriter::new(self),
-        };
-        f(&mut transaction)?;
-        Ok(transaction.inner.apply()?)
+    /// Usage example:
+    /// ```
+    /// use oxigraph::SledStore;
+    /// use oxigraph::model::*;
+    /// use oxigraph::store::sled::SledConflictableTransactionError;
+    /// use std::convert::Infallible;
+    ///
+    /// let store = SledStore::new()?;
+    ///
+    /// let ex = NamedNode::new("http://example.com")?;
+    /// let quad = Quad::new(ex.clone(), ex.clone(), ex.clone(), None);
+    ///
+    /// // transaction
+    /// store.transaction(|transaction| {
+    ///     transaction.insert(&quad)?;
+    ///     Ok(()) as Result<(),SledConflictableTransactionError<Infallible>>
+    /// })?;
+    ///
+    /// // quad filter
+    /// assert!(store.contains(&quad)?);
+    /// # Result::<_,Box<dyn std::error::Error>>::Ok(())
+    /// ```
+    pub fn transaction<T, E>(
+        &self,
+        f: impl Fn(SledTransaction<'_>) -> Result<T, SledConflictableTransactionError<E>>,
+    ) -> Result<T, SledTransactionError<E>> {
+        Ok((&self.id2str, &self.quads)
+            .transaction(move |(id2str, quads)| Ok(f(SledTransaction { id2str, quads })?))?)
     }
 
     /// Loads a graph file (i.e. triples) into the store
@@ -178,13 +202,8 @@ impl SledStore {
         to_graph_name: &GraphName,
         base_iri: Option<&str>,
     ) -> Result<(), io::Error> {
-        load_graph(
-            &mut DirectWriter::new(self),
-            reader,
-            format,
-            to_graph_name,
-            base_iri,
-        )?;
+        let mut this = self;
+        load_graph(&mut this, reader, format, to_graph_name, base_iri)?;
         Ok(())
     }
 
@@ -204,21 +223,23 @@ impl SledStore {
         format: DatasetFormat,
         base_iri: Option<&str>,
     ) -> Result<(), io::Error> {
-        load_dataset(&mut DirectWriter::new(self), reader, format, base_iri)?;
+        let mut this = self;
+        load_dataset(&mut this, reader, format, base_iri)?;
         Ok(())
     }
 
     /// Adds a quad to this store.
     pub fn insert(&self, quad: &Quad) -> Result<(), io::Error> {
-        let mut writer = DirectWriter::new(self);
-        let quad = writer.encode_quad(quad)?;
-        writer.insert_encoded(&quad)
+        let mut this = self;
+        let quad = this.encode_quad(quad)?;
+        this.insert_encoded(&quad)
     }
 
     /// Removes a quad from this store.
     pub fn remove(&self, quad: &Quad) -> Result<(), io::Error> {
+        let mut this = self;
         let quad = quad.into();
-        DirectWriter::new(self).remove_encoded(&quad)
+        this.remove_encoded(&quad)
     }
 
     /// Dumps a store graph into a file.
@@ -470,181 +491,74 @@ impl ReadableEncodedStore for SledStore {
     }
 }
 
-struct DirectWriter<'a> {
-    store: &'a SledStore,
-    buffer: Vec<u8>,
-}
-
-impl<'a> DirectWriter<'a> {
-    fn new(store: &'a SledStore) -> Self {
-        Self {
-            store,
-            buffer: Vec::with_capacity(4 * WRITTEN_TERM_MAX_SIZE + 1),
-        }
-    }
-}
-
-impl WithStoreError for DirectWriter<'_> {
+impl<'a> WithStoreError for &'a SledStore {
     type Error = io::Error;
 }
 
-impl<'a> StrContainer for DirectWriter<'a> {
+impl<'a> StrContainer for &'a SledStore {
     fn insert_str(&mut self, key: StrHash, value: &str) -> Result<(), io::Error> {
-        self.store
-            .id2str
-            .insert(key.to_be_bytes().as_ref(), value)?;
+        self.id2str.insert(key.to_be_bytes().as_ref(), value)?;
         Ok(())
     }
 }
 
-impl<'a> WritableEncodedStore for DirectWriter<'a> {
+impl<'a> WritableEncodedStore for &'a SledStore {
     fn insert_encoded(&mut self, quad: &EncodedQuad) -> Result<(), io::Error> {
-        write_spog_quad(&mut self.buffer, quad);
-        self.store.quads.insert(self.buffer.as_slice(), &[])?;
-        self.buffer.clear();
-
-        write_posg_quad(&mut self.buffer, quad);
-        self.store.quads.insert(self.buffer.as_slice(), &[])?;
-        self.buffer.clear();
-
-        write_ospg_quad(&mut self.buffer, quad);
-        self.store.quads.insert(self.buffer.as_slice(), &[])?;
-        self.buffer.clear();
-
-        write_gspo_quad(&mut self.buffer, quad);
-        self.store.quads.insert(self.buffer.as_slice(), &[])?;
-        self.buffer.clear();
-
-        write_gpos_quad(&mut self.buffer, quad);
-        self.store.quads.insert(self.buffer.as_slice(), &[])?;
-        self.buffer.clear();
-
-        write_gosp_quad(&mut self.buffer, quad);
-        self.store.quads.insert(self.buffer.as_slice(), &[])?;
-        self.buffer.clear();
+        let mut buffer = Vec::with_capacity(4 * WRITTEN_TERM_MAX_SIZE + 1);
 
-        Ok(())
-    }
-
-    fn remove_encoded(&mut self, quad: &EncodedQuad) -> Result<(), io::Error> {
-        write_spog_quad(&mut self.buffer, quad);
-        self.store.quads.remove(self.buffer.as_slice())?;
-        self.buffer.clear();
-
-        write_posg_quad(&mut self.buffer, quad);
-        self.store.quads.remove(self.buffer.as_slice())?;
-        self.buffer.clear();
-
-        write_ospg_quad(&mut self.buffer, quad);
-        self.store.quads.remove(self.buffer.as_slice())?;
-        self.buffer.clear();
-
-        write_gspo_quad(&mut self.buffer, quad);
-        self.store.quads.remove(self.buffer.as_slice())?;
-        self.buffer.clear();
+        write_spog_quad(&mut buffer, quad);
+        self.quads.insert(buffer.as_slice(), &[])?;
+        buffer.clear();
 
-        write_gpos_quad(&mut self.buffer, quad);
-        self.store.quads.remove(self.buffer.as_slice())?;
-        self.buffer.clear();
+        write_posg_quad(&mut buffer, quad);
+        self.quads.insert(buffer.as_slice(), &[])?;
+        buffer.clear();
 
-        write_gosp_quad(&mut self.buffer, quad);
-        self.store.quads.remove(self.buffer.as_slice())?;
-        self.buffer.clear();
+        write_ospg_quad(&mut buffer, quad);
+        self.quads.insert(buffer.as_slice(), &[])?;
+        buffer.clear();
 
-        Ok(())
-    }
-}
+        write_gspo_quad(&mut buffer, quad);
+        self.quads.insert(buffer.as_slice(), &[])?;
+        buffer.clear();
 
-struct BatchWriter<'a> {
-    store: &'a SledStore,
-    quads: Batch,
-    id2str: Batch,
-    buffer: Vec<u8>,
-}
+        write_gpos_quad(&mut buffer, quad);
+        self.quads.insert(buffer.as_slice(), &[])?;
+        buffer.clear();
 
-impl<'a> BatchWriter<'a> {
-    fn new(store: &'a SledStore) -> Self {
-        Self {
-            store,
-            quads: Batch::default(),
-            id2str: Batch::default(),
-            buffer: Vec::with_capacity(4 * WRITTEN_TERM_MAX_SIZE + 1),
-        }
-    }
-}
+        write_gosp_quad(&mut buffer, quad);
+        self.quads.insert(buffer.as_slice(), &[])?;
+        buffer.clear();
 
-impl<'a> BatchWriter<'a> {
-    fn apply(self) -> Result<(), io::Error> {
-        self.store.id2str.apply_batch(self.id2str)?;
-        self.store.quads.apply_batch(self.quads)?;
         Ok(())
     }
-}
-
-impl WithStoreError for BatchWriter<'_> {
-    type Error = Infallible;
-}
 
-impl<'a> StrContainer for BatchWriter<'a> {
-    fn insert_str(&mut self, key: StrHash, value: &str) -> Result<(), Infallible> {
-        self.id2str.insert(key.to_be_bytes().as_ref(), value);
-        Ok(())
-    }
-}
-
-impl<'a> WritableEncodedStore for BatchWriter<'a> {
-    fn insert_encoded(&mut self, quad: &EncodedQuad) -> Result<(), Infallible> {
-        write_spog_quad(&mut self.buffer, quad);
-        self.quads.insert(self.buffer.as_slice(), &[]);
-        self.buffer.clear();
-
-        write_posg_quad(&mut self.buffer, quad);
-        self.quads.insert(self.buffer.as_slice(), &[]);
-        self.buffer.clear();
-
-        write_ospg_quad(&mut self.buffer, quad);
-        self.quads.insert(self.buffer.as_slice(), &[]);
-        self.buffer.clear();
-
-        write_gspo_quad(&mut self.buffer, quad);
-        self.quads.insert(self.buffer.as_slice(), &[]);
-        self.buffer.clear();
-
-        write_gpos_quad(&mut self.buffer, quad);
-        self.quads.insert(self.buffer.as_slice(), &[]);
-        self.buffer.clear();
-
-        write_gosp_quad(&mut self.buffer, quad);
-        self.quads.insert(self.buffer.as_slice(), &[]);
-        self.buffer.clear();
-
-        Ok(())
-    }
+    fn remove_encoded(&mut self, quad: &EncodedQuad) -> Result<(), io::Error> {
+        let mut buffer = Vec::with_capacity(4 * WRITTEN_TERM_MAX_SIZE + 1);
 
-    fn remove_encoded(&mut self, quad: &EncodedQuad) -> Result<(), Infallible> {
-        write_spog_quad(&mut self.buffer, quad);
-        self.quads.remove(self.buffer.as_slice());
-        self.buffer.clear();
+        write_spog_quad(&mut buffer, quad);
+        self.quads.remove(buffer.as_slice())?;
+        buffer.clear();
 
-        write_posg_quad(&mut self.buffer, quad);
-        self.quads.remove(self.buffer.as_slice());
-        self.buffer.clear();
+        write_posg_quad(&mut buffer, quad);
+        self.quads.remove(buffer.as_slice())?;
+        buffer.clear();
 
-        write_ospg_quad(&mut self.buffer, quad);
-        self.quads.remove(self.buffer.as_slice());
-        self.buffer.clear();
+        write_ospg_quad(&mut buffer, quad);
+        self.quads.remove(buffer.as_slice())?;
+        buffer.clear();
 
-        write_gspo_quad(&mut self.buffer, quad);
-        self.quads.remove(self.buffer.as_slice());
-        self.buffer.clear();
+        write_gspo_quad(&mut buffer, quad);
+        self.quads.remove(buffer.as_slice())?;
+        buffer.clear();
 
-        write_gpos_quad(&mut self.buffer, quad);
-        self.quads.remove(self.buffer.as_slice());
-        self.buffer.clear();
+        write_gpos_quad(&mut buffer, quad);
+        self.quads.remove(buffer.as_slice())?;
+        buffer.clear();
 
-        write_gosp_quad(&mut self.buffer, quad);
-        self.quads.remove(self.buffer.as_slice());
-        self.buffer.clear();
+        write_gosp_quad(&mut buffer, quad);
+        self.quads.remove(buffer.as_slice())?;
+        buffer.clear();
 
         Ok(())
     }
@@ -652,7 +566,8 @@ impl<'a> WritableEncodedStore for BatchWriter<'a> {
 
 /// Allows inserting and deleting quads during a transaction with the `SeldStore`.
 pub struct SledTransaction<'a> {
-    inner: BatchWriter<'a>,
+    quads: &'a TransactionalTree,
+    id2str: &'a TransactionalTree,
 }
 
 impl SledTransaction<'_> {
@@ -667,13 +582,14 @@ impl SledTransaction<'_> {
     /// Errors related to parameter validation like the base IRI use the `INVALID_INPUT` error kind.
     /// Errors related to a bad syntax in the loaded file use the `INVALID_DATA` error kind.
     pub fn load_graph(
-        &mut self,
+        &self,
         reader: impl BufRead,
         format: GraphFormat,
         to_graph_name: &GraphName,
         base_iri: Option<&str>,
-    ) -> Result<(), io::Error> {
-        load_graph(&mut self.inner, reader, format, to_graph_name, base_iri)?;
+    ) -> Result<(), SledUnabortableTransactionError> {
+        let mut this = self;
+        load_graph(&mut this, reader, format, to_graph_name, base_iri)?;
         Ok(())
     }
 
@@ -688,25 +604,256 @@ impl SledTransaction<'_> {
     /// Errors related to parameter validation like the base IRI use the `INVALID_INPUT` error kind.
     /// Errors related to a bad syntax in the loaded file use the `INVALID_DATA` error kind.
     pub fn load_dataset(
-        &mut self,
+        &self,
         reader: impl BufRead,
         format: DatasetFormat,
         base_iri: Option<&str>,
-    ) -> Result<(), io::Error> {
-        load_dataset(&mut self.inner, reader, format, base_iri)?;
+    ) -> Result<(), SledUnabortableTransactionError> {
+        let mut this = self;
+        load_dataset(&mut this, reader, format, base_iri)?;
         Ok(())
     }
 
     /// Adds a quad to this store during the transaction.
-    pub fn insert(&mut self, quad: &Quad) {
-        let quad = self.inner.encode_quad(quad).unwrap_infallible();
-        self.inner.insert_encoded(&quad).unwrap_infallible()
+    pub fn insert(&self, quad: &Quad) -> Result<(), SledUnabortableTransactionError> {
+        let mut this = self;
+        let quad = this.encode_quad(quad)?;
+        this.insert_encoded(&quad)
     }
 
     /// Removes a quad from this store during the transaction.
-    pub fn remove(&mut self, quad: &Quad) {
+    pub fn remove(&self, quad: &Quad) -> Result<(), SledUnabortableTransactionError> {
+        let mut this = self;
         let quad = quad.into();
-        self.inner.remove_encoded(&quad).unwrap_infallible()
+        this.remove_encoded(&quad)
+    }
+}
+
+impl<'a> WithStoreError for &'a SledTransaction<'a> {
+    type Error = SledUnabortableTransactionError;
+}
+
+impl<'a> StrContainer for &'a SledTransaction<'a> {
+    fn insert_str(
+        &mut self,
+        key: StrHash,
+        value: &str,
+    ) -> Result<(), SledUnabortableTransactionError> {
+        self.id2str.insert(key.to_be_bytes().as_ref(), value)?;
+        Ok(())
+    }
+}
+
+impl<'a> WritableEncodedStore for &'a SledTransaction<'a> {
+    fn insert_encoded(
+        &mut self,
+        quad: &EncodedQuad,
+    ) -> Result<(), SledUnabortableTransactionError> {
+        let mut buffer = Vec::with_capacity(4 * WRITTEN_TERM_MAX_SIZE + 1);
+
+        write_spog_quad(&mut buffer, quad);
+        self.quads.insert(buffer.as_slice(), &[])?;
+        buffer.clear();
+
+        write_posg_quad(&mut buffer, quad);
+        self.quads.insert(buffer.as_slice(), &[])?;
+        buffer.clear();
+
+        write_ospg_quad(&mut buffer, quad);
+        self.quads.insert(buffer.as_slice(), &[])?;
+        buffer.clear();
+
+        write_gspo_quad(&mut buffer, quad);
+        self.quads.insert(buffer.as_slice(), &[])?;
+        buffer.clear();
+
+        write_gpos_quad(&mut buffer, quad);
+        self.quads.insert(buffer.as_slice(), &[])?;
+        buffer.clear();
+
+        write_gosp_quad(&mut buffer, quad);
+        self.quads.insert(buffer.as_slice(), &[])?;
+        buffer.clear();
+
+        Ok(())
+    }
+
+    fn remove_encoded(
+        &mut self,
+        quad: &EncodedQuad,
+    ) -> Result<(), SledUnabortableTransactionError> {
+        let mut buffer = Vec::with_capacity(4 * WRITTEN_TERM_MAX_SIZE + 1);
+
+        write_spog_quad(&mut buffer, quad);
+        self.quads.remove(buffer.as_slice())?;
+        buffer.clear();
+
+        write_posg_quad(&mut buffer, quad);
+        self.quads.remove(buffer.as_slice())?;
+        buffer.clear();
+
+        write_ospg_quad(&mut buffer, quad);
+        self.quads.remove(buffer.as_slice())?;
+        buffer.clear();
+
+        write_gspo_quad(&mut buffer, quad);
+        self.quads.remove(buffer.as_slice())?;
+        buffer.clear();
+
+        write_gpos_quad(&mut buffer, quad);
+        self.quads.remove(buffer.as_slice())?;
+        buffer.clear();
+
+        write_gosp_quad(&mut buffer, quad);
+        self.quads.remove(buffer.as_slice())?;
+        buffer.clear();
+
+        Ok(())
+    }
+}
+
+/// Error returned by a Sled transaction
+#[derive(Debug)]
+pub enum SledTransactionError<T> {
+    /// An failure returned by the API user that have aborted the transaction
+    Abort(T),
+    /// A storage related error
+    Storage(io::Error),
+}
+
+impl<T: fmt::Display> fmt::Display for SledTransactionError<T> {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        match self {
+            Self::Abort(e) => e.fmt(f),
+            Self::Storage(e) => e.fmt(f),
+        }
+    }
+}
+
+impl<T: Error + 'static> Error for SledTransactionError<T> {
+    fn source(&self) -> Option<&(dyn Error + 'static)> {
+        match self {
+            Self::Abort(e) => Some(e),
+            Self::Storage(e) => Some(e),
+        }
+    }
+}
+
+impl<T> From<TransactionError<T>> for SledTransactionError<T> {
+    fn from(e: TransactionError<T>) -> Self {
+        match e {
+            TransactionError::Abort(e) => Self::Abort(e),
+            TransactionError::Storage(e) => Self::Storage(e.into()),
+        }
+    }
+}
+
+/// An error returned from the transaction methods.
+/// Should be returned as it is
+#[derive(Debug)]
+pub enum SledUnabortableTransactionError {
+    #[doc(hidden)]
+    Conflict,
+    /// A regular error
+    Storage(io::Error),
+}
+
+impl fmt::Display for SledUnabortableTransactionError {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        match self {
+            Self::Conflict => write!(f, "Transaction conflict"),
+            Self::Storage(e) => e.fmt(f),
+        }
+    }
+}
+
+impl Error for SledUnabortableTransactionError {
+    fn source(&self) -> Option<&(dyn Error + 'static)> {
+        match self {
+            Self::Storage(e) => Some(e),
+            _ => None,
+        }
+    }
+}
+
+impl From<SledUnabortableTransactionError> for EvaluationError {
+    fn from(e: SledUnabortableTransactionError) -> Self {
+        match e {
+            SledUnabortableTransactionError::Storage(e) => Self::Io(e),
+            SledUnabortableTransactionError::Conflict => Self::Conflict,
+        }
+    }
+}
+
+impl From<StoreOrParseError<SledUnabortableTransactionError, io::Error>>
+    for SledUnabortableTransactionError
+{
+    fn from(e: StoreOrParseError<SledUnabortableTransactionError, io::Error>) -> Self {
+        match e {
+            StoreOrParseError::Store(e) => e,
+            StoreOrParseError::Parse(e) => Self::Storage(e),
+        }
+    }
+}
+
+impl From<UnabortableTransactionError> for SledUnabortableTransactionError {
+    fn from(e: UnabortableTransactionError) -> Self {
+        match e {
+            UnabortableTransactionError::Storage(e) => Self::Storage(e.into()),
+            UnabortableTransactionError::Conflict => Self::Conflict,
+        }
+    }
+}
+
+/// An error returned from the transaction closure
+#[derive(Debug)]
+pub enum SledConflictableTransactionError<T> {
+    /// A failure returned by the user that will abort the transaction
+    Abort(T),
+    #[doc(hidden)]
+    Conflict,
+    /// A storage related error
+    Storage(io::Error),
+}
+
+impl<T: fmt::Display> fmt::Display for SledConflictableTransactionError<T> {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        match self {
+            Self::Conflict => write!(f, "Transaction conflict"),
+            Self::Storage(e) => e.fmt(f),
+            Self::Abort(e) => e.fmt(f),
+        }
+    }
+}
+
+impl<T: Error + 'static> Error for SledConflictableTransactionError<T> {
+    fn source(&self) -> Option<&(dyn Error + 'static)> {
+        match self {
+            Self::Abort(e) => Some(e),
+            Self::Storage(e) => Some(e),
+            _ => None,
+        }
+    }
+}
+
+impl<T> From<SledUnabortableTransactionError> for SledConflictableTransactionError<T> {
+    fn from(e: SledUnabortableTransactionError) -> Self {
+        match e {
+            SledUnabortableTransactionError::Storage(e) => Self::Storage(e),
+            SledUnabortableTransactionError::Conflict => Self::Conflict,
+        }
+    }
+}
+
+impl<T> From<SledConflictableTransactionError<T>> for ConflictableTransactionError<T> {
+    fn from(e: SledConflictableTransactionError<T>) -> Self {
+        match e {
+            SledConflictableTransactionError::Abort(e) => ConflictableTransactionError::Abort(e),
+            SledConflictableTransactionError::Conflict => ConflictableTransactionError::Conflict,
+            SledConflictableTransactionError::Storage(e) => {
+                ConflictableTransactionError::Storage(e.into())
+            }
+        }
     }
 }