diff --git a/lib/src/sparql/dataset.rs b/lib/src/sparql/dataset.rs
index c410e671..8275b480 100644
--- a/lib/src/sparql/dataset.rs
+++ b/lib/src/sparql/dataset.rs
@@ -1,16 +1,17 @@
 use crate::sparql::algebra::QueryDataset;
 use crate::sparql::EvaluationError;
 use crate::store::numeric_encoder::{
-    EncodedQuad, EncodedTerm, ReadEncoder, StrContainer, StrEncodingAware, StrId, StrLookup,
+    EncodedQuad, EncodedTerm, ReadEncoder, StrContainer, StrEncodingAware, StrHash, StrId,
+    StrLookup,
 };
 use crate::store::ReadableEncodedStore;
-use lasso::{Rodeo, Spur};
 use std::cell::RefCell;
+use std::collections::HashMap;
 use std::iter::{empty, once, Once};
 
 pub(crate) struct DatasetView<S: ReadableEncodedStore> {
     store: S,
-    extra: RefCell<Rodeo>,
+    extra: RefCell<HashMap<StrHash, String>>,
     dataset: EncodedDatasetSpec<S::StrId>,
 }
 
@@ -44,7 +45,7 @@ impl<S: ReadableEncodedStore> DatasetView<S> {
         };
         Ok(Self {
             store,
-            extra: RefCell::new(Rodeo::default()),
+            extra: RefCell::new(HashMap::default()),
             dataset,
         })
     }
@@ -160,14 +161,13 @@ impl<S: ReadableEncodedStore> StrLookup for DatasetView<S> {
     fn get_str(&self, id: DatasetStrId<S::StrId>) -> Result<Option<String>, EvaluationError> {
         match id {
             DatasetStrId::Store(id) => self.store.get_str(id).map_err(|e| e.into()),
-            DatasetStrId::Temporary(id) => {
-                Ok(self.extra.borrow().try_resolve(&id).map(|e| e.to_owned()))
-            }
+            DatasetStrId::Temporary(id) => Ok(self.extra.borrow().get(&id).cloned()),
         }
     }
 
     fn get_str_id(&self, value: &str) -> Result<Option<DatasetStrId<S::StrId>>, EvaluationError> {
-        if let Some(id) = self.extra.borrow().get(value) {
+        let id = StrHash::new(value);
+        if self.extra.borrow().contains_key(&id) {
             Ok(Some(DatasetStrId::Temporary(id)))
         } else {
             Ok(self
@@ -272,9 +272,12 @@ impl<'a, S: ReadableEncodedStore> StrContainer for &'a DatasetView<S> {
         if let Some(id) = self.store.get_str_id(value).map_err(|e| e.into())? {
             Ok(DatasetStrId::Store(id))
         } else {
-            Ok(DatasetStrId::Temporary(
-                self.extra.borrow_mut().get_or_intern(value),
-            ))
+            let hash = StrHash::new(value);
+            self.extra
+                .borrow_mut()
+                .entry(hash)
+                .or_insert_with(|| value.to_owned());
+            Ok(DatasetStrId::Temporary(hash))
         }
     }
 }
@@ -282,7 +285,7 @@ impl<'a, S: ReadableEncodedStore> StrContainer for &'a DatasetView<S> {
 #[derive(Eq, PartialEq, Debug, Copy, Clone, Hash)]
 pub enum DatasetStrId<I: StrId> {
     Store(I),
-    Temporary(Spur),
+    Temporary(StrHash),
 }
 
 impl<I: StrId> StrId for DatasetStrId<I> {}
diff --git a/lib/src/store/binary_encoder.rs b/lib/src/store/binary_encoder.rs
index 95a81866..59863874 100644
--- a/lib/src/store/binary_encoder.rs
+++ b/lib/src/store/binary_encoder.rs
@@ -1,9 +1,7 @@
 use crate::error::invalid_data_error;
 use crate::model::xsd::*;
-use crate::store::numeric_encoder::StrId;
+use crate::store::numeric_encoder::StrHash;
 use crate::store::small_string::SmallString;
-use siphasher::sip128::{Hasher128, SipHasher24};
-use std::hash::Hasher;
 use std::io;
 use std::io::{Cursor, Read};
 use std::mem::size_of;
@@ -51,36 +49,6 @@ const TYPE_DURATION_LITERAL: u8 = 42;
 const TYPE_YEAR_MONTH_DURATION_LITERAL: u8 = 43;
 const TYPE_DAY_TIME_DURATION_LITERAL: u8 = 44;
 
-#[derive(Eq, PartialEq, Debug, Copy, Clone, Hash)]
-#[repr(transparent)]
-pub struct StrHash {
-    hash: u128,
-}
-
-impl StrHash {
-    pub fn new(value: &str) -> Self {
-        let mut hasher = SipHasher24::new();
-        hasher.write(value.as_bytes());
-        Self {
-            hash: hasher.finish128().into(),
-        }
-    }
-
-    #[inline]
-    pub fn from_be_bytes(bytes: [u8; 16]) -> Self {
-        Self {
-            hash: u128::from_be_bytes(bytes),
-        }
-    }
-
-    #[inline]
-    pub fn to_be_bytes(&self) -> [u8; 16] {
-        self.hash.to_be_bytes()
-    }
-}
-
-impl StrId for StrHash {}
-
 #[derive(Clone, Copy)]
 pub enum QuadEncoding {
     Spog,
diff --git a/lib/src/store/numeric_encoder.rs b/lib/src/store/numeric_encoder.rs
index 787252d8..f7821203 100644
--- a/lib/src/store/numeric_encoder.rs
+++ b/lib/src/store/numeric_encoder.rs
@@ -7,6 +7,7 @@ use crate::sparql::EvaluationError;
 use crate::store::small_string::SmallString;
 use rand::random;
 use rio_api::model as rio;
+use siphasher::sip128::{Hasher128, SipHasher24};
 use std::collections::HashMap;
 use std::convert::{TryFrom, TryInto};
 use std::error::Error;
@@ -17,6 +18,36 @@ use std::{fmt, io, str};
 
 pub trait StrId: Eq + Debug + Copy + Hash {}
 
+#[derive(Eq, PartialEq, Debug, Copy, Clone, Hash)]
+#[repr(transparent)]
+pub struct StrHash {
+    hash: u128,
+}
+
+impl StrHash {
+    pub fn new(value: &str) -> Self {
+        let mut hasher = SipHasher24::new();
+        hasher.write(value.as_bytes());
+        Self {
+            hash: hasher.finish128().into(),
+        }
+    }
+
+    #[inline]
+    pub fn from_be_bytes(bytes: [u8; 16]) -> Self {
+        Self {
+            hash: u128::from_be_bytes(bytes),
+        }
+    }
+
+    #[inline]
+    pub fn to_be_bytes(&self) -> [u8; 16] {
+        self.hash.to_be_bytes()
+    }
+}
+
+impl StrId for StrHash {}
+
 #[derive(Debug, Clone, Copy)]
 pub enum EncodedTerm<I: StrId> {
     DefaultGraph,
diff --git a/lib/src/store/sled.rs b/lib/src/store/sled.rs
index cf006512..ab85844f 100644
--- a/lib/src/store/sled.rs
+++ b/lib/src/store/sled.rs
@@ -9,7 +9,7 @@ use crate::sparql::{
 };
 use crate::store::binary_encoder::*;
 use crate::store::numeric_encoder::{
-    Decoder, ReadEncoder, StrContainer, StrEncodingAware, StrLookup, WriteEncoder,
+    Decoder, ReadEncoder, StrContainer, StrEncodingAware, StrHash, StrLookup, WriteEncoder,
 };
 use crate::store::{
     dump_dataset, dump_graph, get_encoded_quad_pattern, load_dataset, load_graph,