Breaking: SledStore: use 3 indexes instead of 6 for the default graph

Factorizes some code

lib/src/store/binary_encoder.rs

@@ -0,0 +1,530 @@
+use crate::error::invalid_data_error;
+use crate::model::xsd::*;
+use crate::store::numeric_encoder::StrId;
+use siphasher::sip128::{Hasher128, SipHasher24};
+use std::hash::Hasher;
+use std::io;
+use std::io::{Cursor, Read};
+use std::mem::size_of;
+
+type EncodedTerm = crate::store::numeric_encoder::EncodedTerm<StrHash>;
+type EncodedQuad = crate::store::numeric_encoder::EncodedQuad<StrHash>;
+
+pub const WRITTEN_TERM_MAX_SIZE: usize = size_of::<u8>() + 2 * size_of::<StrHash>();
+const TYPE_DEFAULT_GRAPH_ID: u8 = 0;
+const TYPE_NAMED_NODE_ID: u8 = 1;
+const TYPE_INLINE_BLANK_NODE_ID: u8 = 2;
+const TYPE_NAMED_BLANK_NODE_ID: u8 = 3;
+const TYPE_LANG_STRING_LITERAL_ID: u8 = 4;
+const TYPE_TYPED_LITERAL_ID: u8 = 5;
+const TYPE_STRING_LITERAL: u8 = 6;
+const TYPE_BOOLEAN_LITERAL_TRUE: u8 = 7;
+const TYPE_BOOLEAN_LITERAL_FALSE: u8 = 8;
+const TYPE_FLOAT_LITERAL: u8 = 9;
+const TYPE_DOUBLE_LITERAL: u8 = 10;
+const TYPE_INTEGER_LITERAL: u8 = 11;
+const TYPE_DECIMAL_LITERAL: u8 = 12;
+const TYPE_DATE_TIME_LITERAL: u8 = 13;
+const TYPE_DATE_LITERAL: u8 = 14;
+const TYPE_TIME_LITERAL: u8 = 15;
+const TYPE_DURATION_LITERAL: u8 = 16;
+const TYPE_YEAR_MONTH_DURATION_LITERAL: u8 = 17;
+const TYPE_DAY_TIME_DURATION_LITERAL: u8 = 18;
+
+pub trait SerializableStrId: StrId {
+    fn len() -> usize;
+
+    fn from_be_bytes(bytes: &[u8]) -> Self;
+
+    fn push_be_bytes(&self, buffer: &mut Vec<u8>);
+}
+
+#[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 {}
+
+impl SerializableStrId for StrHash {
+    fn len() -> usize {
+        16
+    }
+
+    fn from_be_bytes(bytes: &[u8]) -> Self {
+        let mut hash = [0; 16];
+        hash.copy_from_slice(bytes);
+        Self {
+            hash: u128::from_be_bytes(hash),
+        }
+    }
+
+    fn push_be_bytes(&self, buffer: &mut Vec<u8>) {
+        buffer.extend_from_slice(&self.to_be_bytes())
+    }
+}
+
+#[derive(Clone, Copy)]
+pub enum QuadEncoding {
+    SPOG,
+    POSG,
+    OSPG,
+    GSPO,
+    GPOS,
+    GOSP,
+    DSPO,
+    DPOS,
+    DOSP,
+}
+
+impl QuadEncoding {
+    pub fn decode(self, buffer: &[u8]) -> Result<EncodedQuad, io::Error> {
+        let mut cursor = Cursor::new(&buffer);
+        match self {
+            QuadEncoding::SPOG => cursor.read_spog_quad(),
+            QuadEncoding::POSG => cursor.read_posg_quad(),
+            QuadEncoding::OSPG => cursor.read_ospg_quad(),
+            QuadEncoding::GSPO => cursor.read_gspo_quad(),
+            QuadEncoding::GPOS => cursor.read_gpos_quad(),
+            QuadEncoding::GOSP => cursor.read_gosp_quad(),
+            QuadEncoding::DSPO => cursor.read_dspo_quad(),
+            QuadEncoding::DPOS => cursor.read_dpos_quad(),
+            QuadEncoding::DOSP => cursor.read_dosp_quad(),
+        }
+    }
+}
+
+pub trait TermReader {
+    fn read_term(&mut self) -> Result<EncodedTerm, io::Error>;
+
+    fn read_spog_quad(&mut self) -> Result<EncodedQuad, io::Error> {
+        let subject = self.read_term()?;
+        let predicate = self.read_term()?;
+        let object = self.read_term()?;
+        let graph_name = self.read_term()?;
+        Ok(EncodedQuad {
+            subject,
+            predicate,
+            object,
+            graph_name,
+        })
+    }
+
+    fn read_posg_quad(&mut self) -> Result<EncodedQuad, io::Error> {
+        let predicate = self.read_term()?;
+        let object = self.read_term()?;
+        let subject = self.read_term()?;
+        let graph_name = self.read_term()?;
+        Ok(EncodedQuad {
+            subject,
+            predicate,
+            object,
+            graph_name,
+        })
+    }
+
+    fn read_ospg_quad(&mut self) -> Result<EncodedQuad, io::Error> {
+        let object = self.read_term()?;
+        let subject = self.read_term()?;
+        let predicate = self.read_term()?;
+        let graph_name = self.read_term()?;
+        Ok(EncodedQuad {
+            subject,
+            predicate,
+            object,
+            graph_name,
+        })
+    }
+
+    fn read_gspo_quad(&mut self) -> Result<EncodedQuad, io::Error> {
+        let graph_name = self.read_term()?;
+        let subject = self.read_term()?;
+        let predicate = self.read_term()?;
+        let object = self.read_term()?;
+        Ok(EncodedQuad {
+            subject,
+            predicate,
+            object,
+            graph_name,
+        })
+    }
+
+    fn read_gpos_quad(&mut self) -> Result<EncodedQuad, io::Error> {
+        let graph_name = self.read_term()?;
+        let predicate = self.read_term()?;
+        let object = self.read_term()?;
+        let subject = self.read_term()?;
+        Ok(EncodedQuad {
+            subject,
+            predicate,
+            object,
+            graph_name,
+        })
+    }
+
+    fn read_gosp_quad(&mut self) -> Result<EncodedQuad, io::Error> {
+        let graph_name = self.read_term()?;
+        let object = self.read_term()?;
+        let subject = self.read_term()?;
+        let predicate = self.read_term()?;
+        Ok(EncodedQuad {
+            subject,
+            predicate,
+            object,
+            graph_name,
+        })
+    }
+
+    fn read_dspo_quad(&mut self) -> Result<EncodedQuad, io::Error> {
+        let subject = self.read_term()?;
+        let predicate = self.read_term()?;
+        let object = self.read_term()?;
+        Ok(EncodedQuad {
+            subject,
+            predicate,
+            object,
+            graph_name: EncodedTerm::DefaultGraph,
+        })
+    }
+
+    fn read_dpos_quad(&mut self) -> Result<EncodedQuad, io::Error> {
+        let predicate = self.read_term()?;
+        let object = self.read_term()?;
+        let subject = self.read_term()?;
+        Ok(EncodedQuad {
+            subject,
+            predicate,
+            object,
+            graph_name: EncodedTerm::DefaultGraph,
+        })
+    }
+
+    fn read_dosp_quad(&mut self) -> Result<EncodedQuad, io::Error> {
+        let object = self.read_term()?;
+        let subject = self.read_term()?;
+        let predicate = self.read_term()?;
+        Ok(EncodedQuad {
+            subject,
+            predicate,
+            object,
+            graph_name: EncodedTerm::DefaultGraph,
+        })
+    }
+}
+
+impl<R: Read> TermReader for R {
+    fn read_term(&mut self) -> Result<EncodedTerm, io::Error> {
+        let mut type_buffer = [0];
+        self.read_exact(&mut type_buffer)?;
+        match type_buffer[0] {
+            TYPE_DEFAULT_GRAPH_ID => Ok(EncodedTerm::DefaultGraph),
+            TYPE_NAMED_NODE_ID => {
+                let mut buffer = [0; 16];
+                self.read_exact(&mut buffer)?;
+                Ok(EncodedTerm::NamedNode {
+                    iri_id: StrHash::from_be_bytes(buffer),
+                })
+            }
+            TYPE_INLINE_BLANK_NODE_ID => {
+                let mut buffer = [0; 16];
+                self.read_exact(&mut buffer)?;
+                Ok(EncodedTerm::InlineBlankNode {
+                    id: u128::from_be_bytes(buffer),
+                })
+            }
+            TYPE_NAMED_BLANK_NODE_ID => {
+                let mut buffer = [0; 16];
+                self.read_exact(&mut buffer)?;
+                Ok(EncodedTerm::NamedBlankNode {
+                    id_id: StrHash::from_be_bytes(buffer),
+                })
+            }
+            TYPE_LANG_STRING_LITERAL_ID => {
+                let mut language_buffer = [0; 16];
+                self.read_exact(&mut language_buffer)?;
+                let mut value_buffer = [0; 16];
+                self.read_exact(&mut value_buffer)?;
+                Ok(EncodedTerm::LangStringLiteral {
+                    language_id: StrHash::from_be_bytes(language_buffer),
+                    value_id: StrHash::from_be_bytes(value_buffer),
+                })
+            }
+            TYPE_TYPED_LITERAL_ID => {
+                let mut datatype_buffer = [0; 16];
+                self.read_exact(&mut datatype_buffer)?;
+                let mut value_buffer = [0; 16];
+                self.read_exact(&mut value_buffer)?;
+                Ok(EncodedTerm::TypedLiteral {
+                    datatype_id: StrHash::from_be_bytes(datatype_buffer),
+                    value_id: StrHash::from_be_bytes(value_buffer),
+                })
+            }
+            TYPE_STRING_LITERAL => {
+                let mut buffer = [0; 16];
+                self.read_exact(&mut buffer)?;
+                Ok(EncodedTerm::StringLiteral {
+                    value_id: StrHash::from_be_bytes(buffer),
+                })
+            }
+            TYPE_BOOLEAN_LITERAL_TRUE => Ok(EncodedTerm::BooleanLiteral(true)),
+            TYPE_BOOLEAN_LITERAL_FALSE => Ok(EncodedTerm::BooleanLiteral(false)),
+            TYPE_FLOAT_LITERAL => {
+                let mut buffer = [0; 4];
+                self.read_exact(&mut buffer)?;
+                Ok(EncodedTerm::FloatLiteral(f32::from_be_bytes(buffer)))
+            }
+            TYPE_DOUBLE_LITERAL => {
+                let mut buffer = [0; 8];
+                self.read_exact(&mut buffer)?;
+                Ok(EncodedTerm::DoubleLiteral(f64::from_be_bytes(buffer)))
+            }
+            TYPE_INTEGER_LITERAL => {
+                let mut buffer = [0; 8];
+                self.read_exact(&mut buffer)?;
+                Ok(EncodedTerm::IntegerLiteral(i64::from_be_bytes(buffer)))
+            }
+            TYPE_DECIMAL_LITERAL => {
+                let mut buffer = [0; 16];
+                self.read_exact(&mut buffer)?;
+                Ok(EncodedTerm::DecimalLiteral(Decimal::from_be_bytes(buffer)))
+            }
+            TYPE_DATE_LITERAL => {
+                let mut buffer = [0; 18];
+                self.read_exact(&mut buffer)?;
+                Ok(EncodedTerm::DateLiteral(Date::from_be_bytes(buffer)))
+            }
+            TYPE_TIME_LITERAL => {
+                let mut buffer = [0; 18];
+                self.read_exact(&mut buffer)?;
+                Ok(EncodedTerm::TimeLiteral(Time::from_be_bytes(buffer)))
+            }
+            TYPE_DATE_TIME_LITERAL => {
+                let mut buffer = [0; 18];
+                self.read_exact(&mut buffer)?;
+                Ok(EncodedTerm::DateTimeLiteral(DateTime::from_be_bytes(
+                    buffer,
+                )))
+            }
+            TYPE_DURATION_LITERAL => {
+                let mut buffer = [0; 24];
+                self.read_exact(&mut buffer)?;
+                Ok(EncodedTerm::DurationLiteral(Duration::from_be_bytes(
+                    buffer,
+                )))
+            }
+            TYPE_YEAR_MONTH_DURATION_LITERAL => {
+                let mut buffer = [0; 8];
+                self.read_exact(&mut buffer)?;
+                Ok(EncodedTerm::YearMonthDurationLiteral(
+                    YearMonthDuration::from_be_bytes(buffer),
+                ))
+            }
+            TYPE_DAY_TIME_DURATION_LITERAL => {
+                let mut buffer = [0; 16];
+                self.read_exact(&mut buffer)?;
+                Ok(EncodedTerm::DayTimeDurationLiteral(
+                    DayTimeDuration::from_be_bytes(buffer),
+                ))
+            }
+            _ => Err(invalid_data_error("the term buffer has an invalid type id")),
+        }
+    }
+}
+
+pub fn write_spog_quad(sink: &mut Vec<u8>, quad: &EncodedQuad) {
+    write_term(sink, quad.subject);
+    write_term(sink, quad.predicate);
+    write_term(sink, quad.object);
+    write_term(sink, quad.graph_name);
+}
+
+pub fn write_posg_quad(sink: &mut Vec<u8>, quad: &EncodedQuad) {
+    write_term(sink, quad.predicate);
+    write_term(sink, quad.object);
+    write_term(sink, quad.subject);
+    write_term(sink, quad.graph_name);
+}
+
+pub fn write_ospg_quad(sink: &mut Vec<u8>, quad: &EncodedQuad) {
+    write_term(sink, quad.object);
+    write_term(sink, quad.subject);
+    write_term(sink, quad.predicate);
+    write_term(sink, quad.graph_name);
+}
+
+pub fn write_gspo_quad(sink: &mut Vec<u8>, quad: &EncodedQuad) {
+    write_term(sink, quad.graph_name);
+    write_term(sink, quad.subject);
+    write_term(sink, quad.predicate);
+    write_term(sink, quad.object);
+}
+
+pub fn write_gpos_quad(sink: &mut Vec<u8>, quad: &EncodedQuad) {
+    write_term(sink, quad.graph_name);
+    write_term(sink, quad.predicate);
+    write_term(sink, quad.object);
+    write_term(sink, quad.subject);
+}
+
+pub fn write_gosp_quad(sink: &mut Vec<u8>, quad: &EncodedQuad) {
+    write_term(sink, quad.graph_name);
+    write_term(sink, quad.object);
+    write_term(sink, quad.subject);
+    write_term(sink, quad.predicate);
+}
+
+pub fn write_spo_quad(sink: &mut Vec<u8>, quad: &EncodedQuad) {
+    write_term(sink, quad.subject);
+    write_term(sink, quad.predicate);
+    write_term(sink, quad.object);
+}
+
+pub fn write_pos_quad(sink: &mut Vec<u8>, quad: &EncodedQuad) {
+    write_term(sink, quad.predicate);
+    write_term(sink, quad.object);
+    write_term(sink, quad.subject);
+}
+
+pub fn write_osp_quad(sink: &mut Vec<u8>, quad: &EncodedQuad) {
+    write_term(sink, quad.object);
+    write_term(sink, quad.subject);
+    write_term(sink, quad.predicate);
+}
+
+pub fn encode_term(t: EncodedTerm) -> Vec<u8> {
+    let mut vec = Vec::with_capacity(WRITTEN_TERM_MAX_SIZE);
+    write_term(&mut vec, t);
+    vec
+}
+
+pub fn encode_term_pair(t1: EncodedTerm, t2: EncodedTerm) -> Vec<u8> {
+    let mut vec = Vec::with_capacity(2 * WRITTEN_TERM_MAX_SIZE);
+    write_term(&mut vec, t1);
+    write_term(&mut vec, t2);
+    vec
+}
+
+pub fn encode_term_triple(t1: EncodedTerm, t2: EncodedTerm, t3: EncodedTerm) -> Vec<u8> {
+    let mut vec = Vec::with_capacity(3 * WRITTEN_TERM_MAX_SIZE);
+    write_term(&mut vec, t1);
+    write_term(&mut vec, t2);
+    write_term(&mut vec, t3);
+    vec
+}
+
+pub fn encode_term_quad(
+    t1: EncodedTerm,
+    t2: EncodedTerm,
+    t3: EncodedTerm,
+    t4: EncodedTerm,
+) -> Vec<u8> {
+    let mut vec = Vec::with_capacity(4 * WRITTEN_TERM_MAX_SIZE);
+    write_term(&mut vec, t1);
+    write_term(&mut vec, t2);
+    write_term(&mut vec, t3);
+    write_term(&mut vec, t4);
+    vec
+}
+
+pub fn write_term(sink: &mut Vec<u8>, term: EncodedTerm) {
+    match term {
+        EncodedTerm::DefaultGraph => sink.push(TYPE_DEFAULT_GRAPH_ID),
+        EncodedTerm::NamedNode { iri_id } => {
+            sink.push(TYPE_NAMED_NODE_ID);
+            iri_id.push_be_bytes(sink)
+        }
+        EncodedTerm::InlineBlankNode { id } => {
+            sink.push(TYPE_INLINE_BLANK_NODE_ID);
+            sink.extend_from_slice(&id.to_be_bytes())
+        }
+        EncodedTerm::NamedBlankNode { id_id } => {
+            sink.push(TYPE_NAMED_BLANK_NODE_ID);
+            id_id.push_be_bytes(sink)
+        }
+        EncodedTerm::StringLiteral { value_id } => {
+            sink.push(TYPE_STRING_LITERAL);
+            value_id.push_be_bytes(sink)
+        }
+        EncodedTerm::LangStringLiteral {
+            value_id,
+            language_id,
+        } => {
+            sink.push(TYPE_LANG_STRING_LITERAL_ID);
+            value_id.push_be_bytes(sink);
+            language_id.push_be_bytes(sink);
+        }
+        EncodedTerm::TypedLiteral {
+            value_id,
+            datatype_id,
+        } => {
+            sink.push(TYPE_TYPED_LITERAL_ID);
+            value_id.push_be_bytes(sink);
+            datatype_id.push_be_bytes(sink);
+        }
+        EncodedTerm::BooleanLiteral(true) => sink.push(TYPE_BOOLEAN_LITERAL_TRUE),
+        EncodedTerm::BooleanLiteral(false) => sink.push(TYPE_BOOLEAN_LITERAL_FALSE),
+        EncodedTerm::FloatLiteral(value) => {
+            sink.push(TYPE_FLOAT_LITERAL);
+            sink.extend_from_slice(&value.to_be_bytes())
+        }
+        EncodedTerm::DoubleLiteral(value) => {
+            sink.push(TYPE_DOUBLE_LITERAL);
+            sink.extend_from_slice(&value.to_be_bytes())
+        }
+        EncodedTerm::IntegerLiteral(value) => {
+            sink.push(TYPE_INTEGER_LITERAL);
+            sink.extend_from_slice(&value.to_be_bytes())
+        }
+        EncodedTerm::DecimalLiteral(value) => {
+            sink.push(TYPE_DECIMAL_LITERAL);
+            sink.extend_from_slice(&value.to_be_bytes())
+        }
+        EncodedTerm::DateLiteral(value) => {
+            sink.push(TYPE_DATE_LITERAL);
+            sink.extend_from_slice(&value.to_be_bytes())
+        }
+        EncodedTerm::TimeLiteral(value) => {
+            sink.push(TYPE_TIME_LITERAL);
+            sink.extend_from_slice(&value.to_be_bytes())
+        }
+        EncodedTerm::DateTimeLiteral(value) => {
+            sink.push(TYPE_DATE_TIME_LITERAL);
+            sink.extend_from_slice(&value.to_be_bytes())
+        }
+        EncodedTerm::DurationLiteral(value) => {
+            sink.push(TYPE_DURATION_LITERAL);
+            sink.extend_from_slice(&value.to_be_bytes())
+        }
+        EncodedTerm::YearMonthDurationLiteral(value) => {
+            sink.push(TYPE_YEAR_MONTH_DURATION_LITERAL);
+            sink.extend_from_slice(&value.to_be_bytes())
+        }
+        EncodedTerm::DayTimeDurationLiteral(value) => {
+            sink.push(TYPE_DAY_TIME_DURATION_LITERAL);
+            sink.extend_from_slice(&value.to_be_bytes())
+        }
+    }
+}

lib/src/store/mod.rs

@@ -3,6 +3,8 @@
 //! They encode a [RDF dataset](https://www.w3.org/TR/rdf11-concepts/#dfn-rdf-dataset)
 //! and allow querying and updating them using SPARQL.
 
+#[cfg(any(feature = "rocksdb", feature = "sled"))]
+mod binary_encoder;
 pub mod memory;
 pub(crate) mod numeric_encoder;
 #[cfg(feature = "rocksdb")]

lib/src/store/numeric_encoder.rs

@@ -4,97 +4,19 @@ use crate::error::invalid_data_error;
 use crate::model::xsd::*;
 use crate::model::*;
 use crate::sparql::EvaluationError;
+use lasso::{Rodeo, Spur};
 use rand::random;
 use rio_api::model as rio;
-use siphasher::sip128::{Hasher128, SipHasher24};
 use std::collections::HashMap;
 use std::convert::Infallible;
 use std::error::Error;
 use std::fmt::Debug;
 use std::hash::Hash;
 use std::hash::Hasher;
-use std::io::Read;
-use std::mem::size_of;
 use std::{fmt, io, str};
 
 pub trait StrId: Eq + Debug + Copy + Hash {}
 
-pub trait SerializableStrId: StrId {
-    fn len() -> usize;
-
-    fn from_be_bytes(bytes: &[u8]) -> Self;
-
-    fn push_be_bytes(&self, buffer: &mut Vec<u8>);
-}
-
-#[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 {}
-
-impl SerializableStrId for StrHash {
-    fn len() -> usize {
-        16
-    }
-
-    fn from_be_bytes(bytes: &[u8]) -> Self {
-        let mut hash = [0; 16];
-        hash.copy_from_slice(bytes);
-        Self {
-            hash: u128::from_be_bytes(hash),
-        }
-    }
-
-    fn push_be_bytes(&self, buffer: &mut Vec<u8>) {
-        buffer.extend_from_slice(&self.to_be_bytes())
-    }
-}
-
-const TYPE_DEFAULT_GRAPH_ID: u8 = 0;
-const TYPE_NAMED_NODE_ID: u8 = 1;
-const TYPE_INLINE_BLANK_NODE_ID: u8 = 2;
-const TYPE_NAMED_BLANK_NODE_ID: u8 = 3;
-const TYPE_LANG_STRING_LITERAL_ID: u8 = 4;
-const TYPE_TYPED_LITERAL_ID: u8 = 5;
-const TYPE_STRING_LITERAL: u8 = 6;
-const TYPE_BOOLEAN_LITERAL_TRUE: u8 = 7;
-const TYPE_BOOLEAN_LITERAL_FALSE: u8 = 8;
-const TYPE_FLOAT_LITERAL: u8 = 9;
-const TYPE_DOUBLE_LITERAL: u8 = 10;
-const TYPE_INTEGER_LITERAL: u8 = 11;
-const TYPE_DECIMAL_LITERAL: u8 = 12;
-const TYPE_DATE_TIME_LITERAL: u8 = 13;
-const TYPE_DATE_LITERAL: u8 = 14;
-const TYPE_TIME_LITERAL: u8 = 15;
-const TYPE_DURATION_LITERAL: u8 = 16;
-const TYPE_YEAR_MONTH_DURATION_LITERAL: u8 = 17;
-const TYPE_DAY_TIME_DURATION_LITERAL: u8 = 18;
-
 #[derive(Debug, Clone, Copy)]
 pub enum EncodedTerm<I: StrId> {
     DefaultGraph,
@@ -264,30 +186,6 @@ impl<I: StrId> EncodedTerm<I> {
         *self == EncodedTerm::DefaultGraph
     }
 
-    fn type_id(&self) -> u8 {
-        match self {
-            Self::DefaultGraph { .. } => TYPE_DEFAULT_GRAPH_ID,
-            Self::NamedNode { .. } => TYPE_NAMED_NODE_ID,
-            Self::InlineBlankNode { .. } => TYPE_INLINE_BLANK_NODE_ID,
-            Self::NamedBlankNode { .. } => TYPE_NAMED_BLANK_NODE_ID,
-            Self::StringLiteral { .. } => TYPE_STRING_LITERAL,
-            Self::LangStringLiteral { .. } => TYPE_LANG_STRING_LITERAL_ID,
-            Self::TypedLiteral { .. } => TYPE_TYPED_LITERAL_ID,
-            Self::BooleanLiteral(true) => TYPE_BOOLEAN_LITERAL_TRUE,
-            Self::BooleanLiteral(false) => TYPE_BOOLEAN_LITERAL_FALSE,
-            Self::FloatLiteral(_) => TYPE_FLOAT_LITERAL,
-            Self::DoubleLiteral(_) => TYPE_DOUBLE_LITERAL,
-            Self::IntegerLiteral(_) => TYPE_INTEGER_LITERAL,
-            Self::DecimalLiteral(_) => TYPE_DECIMAL_LITERAL,
-            Self::DateLiteral(_) => TYPE_DATE_LITERAL,
-            Self::TimeLiteral(_) => TYPE_TIME_LITERAL,
-            Self::DateTimeLiteral(_) => TYPE_DATE_TIME_LITERAL,
-            Self::DurationLiteral(_) => TYPE_DURATION_LITERAL,
-            Self::YearMonthDurationLiteral(_) => TYPE_YEAR_MONTH_DURATION_LITERAL,
-            Self::DayTimeDurationLiteral(_) => TYPE_DAY_TIME_DURATION_LITERAL,
-        }
-    }
-
     pub fn map_id<J: StrId>(self, mapping: impl Fn(I) -> J) -> EncodedTerm<J> {
         match self {
             Self::DefaultGraph { .. } => EncodedTerm::DefaultGraph,
@@ -478,283 +376,6 @@ impl<I: StrId> EncodedQuad<I> {
     }
 }
 
-pub trait TermReader {
-    fn read_term(&mut self) -> Result<EncodedTerm<StrHash>, io::Error>;
-
-    fn read_spog_quad(&mut self) -> Result<EncodedQuad<StrHash>, io::Error> {
-        let subject = self.read_term()?;
-        let predicate = self.read_term()?;
-        let object = self.read_term()?;
-        let graph_name = self.read_term()?;
-        Ok(EncodedQuad {
-            subject,
-            predicate,
-            object,
-            graph_name,
-        })
-    }
-
-    fn read_posg_quad(&mut self) -> Result<EncodedQuad<StrHash>, io::Error> {
-        let predicate = self.read_term()?;
-        let object = self.read_term()?;
-        let subject = self.read_term()?;
-        let graph_name = self.read_term()?;
-        Ok(EncodedQuad {
-            subject,
-            predicate,
-            object,
-            graph_name,
-        })
-    }
-
-    fn read_ospg_quad(&mut self) -> Result<EncodedQuad<StrHash>, io::Error> {
-        let object = self.read_term()?;
-        let subject = self.read_term()?;
-        let predicate = self.read_term()?;
-        let graph_name = self.read_term()?;
-        Ok(EncodedQuad {
-            subject,
-            predicate,
-            object,
-            graph_name,
-        })
-    }
-
-    fn read_gspo_quad(&mut self) -> Result<EncodedQuad<StrHash>, io::Error> {
-        let graph_name = self.read_term()?;
-        let subject = self.read_term()?;
-        let predicate = self.read_term()?;
-        let object = self.read_term()?;
-        Ok(EncodedQuad {
-            subject,
-            predicate,
-            object,
-            graph_name,
-        })
-    }
-
-    fn read_gpos_quad(&mut self) -> Result<EncodedQuad<StrHash>, io::Error> {
-        let graph_name = self.read_term()?;
-        let predicate = self.read_term()?;
-        let object = self.read_term()?;
-        let subject = self.read_term()?;
-        Ok(EncodedQuad {
-            subject,
-            predicate,
-            object,
-            graph_name,
-        })
-    }
-
-    fn read_gosp_quad(&mut self) -> Result<EncodedQuad<StrHash>, io::Error> {
-        let graph_name = self.read_term()?;
-        let object = self.read_term()?;
-        let subject = self.read_term()?;
-        let predicate = self.read_term()?;
-        Ok(EncodedQuad {
-            subject,
-            predicate,
-            object,
-            graph_name,
-        })
-    }
-
-    fn read_dspo_quad(&mut self) -> Result<EncodedQuad<StrHash>, io::Error> {
-        let subject = self.read_term()?;
-        let predicate = self.read_term()?;
-        let object = self.read_term()?;
-        Ok(EncodedQuad {
-            subject,
-            predicate,
-            object,
-            graph_name: EncodedTerm::DefaultGraph,
-        })
-    }
-
-    fn read_dpos_quad(&mut self) -> Result<EncodedQuad<StrHash>, io::Error> {
-        let predicate = self.read_term()?;
-        let object = self.read_term()?;
-        let subject = self.read_term()?;
-        Ok(EncodedQuad {
-            subject,
-            predicate,
-            object,
-            graph_name: EncodedTerm::DefaultGraph,
-        })
-    }
-
-    fn read_dosp_quad(&mut self) -> Result<EncodedQuad<StrHash>, io::Error> {
-        let object = self.read_term()?;
-        let subject = self.read_term()?;
-        let predicate = self.read_term()?;
-        Ok(EncodedQuad {
-            subject,
-            predicate,
-            object,
-            graph_name: EncodedTerm::DefaultGraph,
-        })
-    }
-}
-
-impl<R: Read> TermReader for R {
-    fn read_term(&mut self) -> Result<EncodedTerm<StrHash>, io::Error> {
-        let mut type_buffer = [0];
-        self.read_exact(&mut type_buffer)?;
-        match type_buffer[0] {
-            TYPE_DEFAULT_GRAPH_ID => Ok(EncodedTerm::DefaultGraph),
-            TYPE_NAMED_NODE_ID => {
-                let mut buffer = [0; 16];
-                self.read_exact(&mut buffer)?;
-                Ok(EncodedTerm::NamedNode {
-                    iri_id: StrHash::from_be_bytes(buffer),
-                })
-            }
-            TYPE_INLINE_BLANK_NODE_ID => {
-                let mut buffer = [0; 16];
-                self.read_exact(&mut buffer)?;
-                Ok(EncodedTerm::InlineBlankNode {
-                    id: u128::from_be_bytes(buffer),
-                })
-            }
-            TYPE_NAMED_BLANK_NODE_ID => {
-                let mut buffer = [0; 16];
-                self.read_exact(&mut buffer)?;
-                Ok(EncodedTerm::NamedBlankNode {
-                    id_id: StrHash::from_be_bytes(buffer),
-                })
-            }
-            TYPE_LANG_STRING_LITERAL_ID => {
-                let mut language_buffer = [0; 16];
-                self.read_exact(&mut language_buffer)?;
-                let mut value_buffer = [0; 16];
-                self.read_exact(&mut value_buffer)?;
-                Ok(EncodedTerm::LangStringLiteral {
-                    language_id: StrHash::from_be_bytes(language_buffer),
-                    value_id: StrHash::from_be_bytes(value_buffer),
-                })
-            }
-            TYPE_TYPED_LITERAL_ID => {
-                let mut datatype_buffer = [0; 16];
-                self.read_exact(&mut datatype_buffer)?;
-                let mut value_buffer = [0; 16];
-                self.read_exact(&mut value_buffer)?;
-                Ok(EncodedTerm::TypedLiteral {
-                    datatype_id: StrHash::from_be_bytes(datatype_buffer),
-                    value_id: StrHash::from_be_bytes(value_buffer),
-                })
-            }
-            TYPE_STRING_LITERAL => {
-                let mut buffer = [0; 16];
-                self.read_exact(&mut buffer)?;
-                Ok(EncodedTerm::StringLiteral {
-                    value_id: StrHash::from_be_bytes(buffer),
-                })
-            }
-            TYPE_BOOLEAN_LITERAL_TRUE => Ok(EncodedTerm::BooleanLiteral(true)),
-            TYPE_BOOLEAN_LITERAL_FALSE => Ok(EncodedTerm::BooleanLiteral(false)),
-            TYPE_FLOAT_LITERAL => {
-                let mut buffer = [0; 4];
-                self.read_exact(&mut buffer)?;
-                Ok(EncodedTerm::FloatLiteral(f32::from_be_bytes(buffer)))
-            }
-            TYPE_DOUBLE_LITERAL => {
-                let mut buffer = [0; 8];
-                self.read_exact(&mut buffer)?;
-                Ok(EncodedTerm::DoubleLiteral(f64::from_be_bytes(buffer)))
-            }
-            TYPE_INTEGER_LITERAL => {
-                let mut buffer = [0; 8];
-                self.read_exact(&mut buffer)?;
-                Ok(EncodedTerm::IntegerLiteral(i64::from_be_bytes(buffer)))
-            }
-            TYPE_DECIMAL_LITERAL => {
-                let mut buffer = [0; 16];
-                self.read_exact(&mut buffer)?;
-                Ok(EncodedTerm::DecimalLiteral(Decimal::from_be_bytes(buffer)))
-            }
-            TYPE_DATE_LITERAL => {
-                let mut buffer = [0; 18];
-                self.read_exact(&mut buffer)?;
-                Ok(EncodedTerm::DateLiteral(Date::from_be_bytes(buffer)))
-            }
-            TYPE_TIME_LITERAL => {
-                let mut buffer = [0; 18];
-                self.read_exact(&mut buffer)?;
-                Ok(EncodedTerm::TimeLiteral(Time::from_be_bytes(buffer)))
-            }
-            TYPE_DATE_TIME_LITERAL => {
-                let mut buffer = [0; 18];
-                self.read_exact(&mut buffer)?;
-                Ok(EncodedTerm::DateTimeLiteral(DateTime::from_be_bytes(
-                    buffer,
-                )))
-            }
-            TYPE_DURATION_LITERAL => {
-                let mut buffer = [0; 24];
-                self.read_exact(&mut buffer)?;
-                Ok(EncodedTerm::DurationLiteral(Duration::from_be_bytes(
-                    buffer,
-                )))
-            }
-            TYPE_YEAR_MONTH_DURATION_LITERAL => {
-                let mut buffer = [0; 8];
-                self.read_exact(&mut buffer)?;
-                Ok(EncodedTerm::YearMonthDurationLiteral(
-                    YearMonthDuration::from_be_bytes(buffer),
-                ))
-            }
-            TYPE_DAY_TIME_DURATION_LITERAL => {
-                let mut buffer = [0; 16];
-                self.read_exact(&mut buffer)?;
-                Ok(EncodedTerm::DayTimeDurationLiteral(
-                    DayTimeDuration::from_be_bytes(buffer),
-                ))
-            }
-            _ => Err(invalid_data_error("the term buffer has an invalid type id")),
-        }
-    }
-}
-
-pub const WRITTEN_TERM_MAX_SIZE: usize = size_of::<u8>() + 2 * size_of::<StrHash>();
-
-pub fn write_term<I: SerializableStrId>(sink: &mut Vec<u8>, term: EncodedTerm<I>) {
-    sink.push(term.type_id());
-    match term {
-        EncodedTerm::DefaultGraph => {}
-        EncodedTerm::NamedNode { iri_id } => iri_id.push_be_bytes(sink),
-        EncodedTerm::InlineBlankNode { id } => sink.extend_from_slice(&id.to_be_bytes()),
-        EncodedTerm::NamedBlankNode { id_id } => id_id.push_be_bytes(sink),
-        EncodedTerm::StringLiteral { value_id } => value_id.push_be_bytes(sink),
-        EncodedTerm::LangStringLiteral {
-            value_id,
-            language_id,
-        } => {
-            value_id.push_be_bytes(sink);
-            language_id.push_be_bytes(sink);
-        }
-        EncodedTerm::TypedLiteral {
-            value_id,
-            datatype_id,
-        } => {
-            value_id.push_be_bytes(sink);
-            datatype_id.push_be_bytes(sink);
-        }
-        EncodedTerm::BooleanLiteral(_) => {}
-        EncodedTerm::FloatLiteral(value) => sink.extend_from_slice(&value.to_be_bytes()),
-        EncodedTerm::DoubleLiteral(value) => sink.extend_from_slice(&value.to_be_bytes()),
-        EncodedTerm::IntegerLiteral(value) => sink.extend_from_slice(&value.to_be_bytes()),
-        EncodedTerm::DecimalLiteral(value) => sink.extend_from_slice(&value.to_be_bytes()),
-        EncodedTerm::DateLiteral(value) => sink.extend_from_slice(&value.to_be_bytes()),
-        EncodedTerm::TimeLiteral(value) => sink.extend_from_slice(&value.to_be_bytes()),
-        EncodedTerm::DateTimeLiteral(value) => sink.extend_from_slice(&value.to_be_bytes()),
-        EncodedTerm::DurationLiteral(value) => sink.extend_from_slice(&value.to_be_bytes()),
-        EncodedTerm::YearMonthDurationLiteral(value) => {
-            sink.extend_from_slice(&value.to_be_bytes())
-        }
-        EncodedTerm::DayTimeDurationLiteral(value) => sink.extend_from_slice(&value.to_be_bytes()),
-    }
-}
-
 pub(crate) trait WithStoreError {
     //TODO: rename
     type Error: Error + Into<EvaluationError> + 'static;
@@ -776,44 +397,32 @@ pub(crate) trait StrContainer: WithStoreError {
     fn insert_str(&mut self, value: &str) -> Result<Self::StrId, Self::Error>;
 }
 
+#[derive(Default)]
 pub struct MemoryStrStore {
-    id2str: HashMap<StrHash, String>,
+    inner: Rodeo,
 }
 
-impl Default for MemoryStrStore {
-    fn default() -> Self {
-        Self {
-            id2str: HashMap::default(),
-        }
-    }
-}
+impl StrId for Spur {}
 
 impl WithStoreError for MemoryStrStore {
     type Error = Infallible;
-    type StrId = StrHash;
+    type StrId = Spur;
 }
 
 impl StrLookup for MemoryStrStore {
-    fn get_str(&self, id: StrHash) -> Result<Option<String>, Infallible> {
+    fn get_str(&self, id: Spur) -> Result<Option<String>, Infallible> {
         //TODO: avoid copy by adding a lifetime limit to get_str
-        Ok(self.id2str.get(&id).cloned())
+        Ok(self.inner.try_resolve(&id).map(|e| e.to_owned()))
     }
 
-    fn get_str_id(&self, value: &str) -> Result<Option<StrHash>, Infallible> {
-        let id = StrHash::new(value);
-        Ok(if self.id2str.contains_key(&id) {
-            Some(id)
-        } else {
-            None
-        })
+    fn get_str_id(&self, value: &str) -> Result<Option<Spur>, Infallible> {
+        Ok(self.inner.get(value))
     }
 }
 
 impl StrContainer for MemoryStrStore {
-    fn insert_str(&mut self, value: &str) -> Result<StrHash, Infallible> {
-        let key = StrHash::new(value);
-        self.id2str.entry(key).or_insert_with(|| value.to_owned());
-        Ok(key)
+    fn insert_str(&mut self, value: &str) -> Result<Spur, Infallible> {
+        Ok(self.inner.get_or_intern(value))
     }
 }
 

lib/src/store/rocksdb.rs

@@ -4,9 +4,9 @@ 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::binary_encoder::*;
 use crate::store::numeric_encoder::{
-    write_term, Decoder, ReadEncoder, StrContainer, StrHash, StrLookup, TermReader, WithStoreError,
-    WriteEncoder, WRITTEN_TERM_MAX_SIZE,
+    Decoder, ReadEncoder, StrContainer, StrLookup, WithStoreError, WriteEncoder,
 };
 use crate::store::{
     dump_dataset, dump_graph, get_encoded_quad_pattern, load_dataset, load_graph,
@@ -16,7 +16,7 @@ use rocksdb::*;
 use std::collections::HashMap;
 use std::convert::TryInto;
 use std::io;
-use std::io::{BufRead, Cursor, Write};
+use std::io::{BufRead, Write};
 use std::iter::{once, Once};
 use std::mem::{take, transmute};
 use std::path::Path;
@@ -1045,36 +1045,6 @@ fn get_cf<'a>(db: &'a DB, name: &str) -> &'a ColumnFamily {
         .expect("A column family that should exist in RocksDB does not exist")
 }
 
-fn encode_term(t: EncodedTerm) -> Vec<u8> {
-    let mut vec = Vec::with_capacity(WRITTEN_TERM_MAX_SIZE);
-    write_term(&mut vec, t);
-    vec
-}
-
-fn encode_term_pair(t1: EncodedTerm, t2: EncodedTerm) -> Vec<u8> {
-    let mut vec = Vec::with_capacity(2 * WRITTEN_TERM_MAX_SIZE);
-    write_term(&mut vec, t1);
-    write_term(&mut vec, t2);
-    vec
-}
-
-fn encode_term_triple(t1: EncodedTerm, t2: EncodedTerm, t3: EncodedTerm) -> Vec<u8> {
-    let mut vec = Vec::with_capacity(3 * WRITTEN_TERM_MAX_SIZE);
-    write_term(&mut vec, t1);
-    write_term(&mut vec, t2);
-    write_term(&mut vec, t3);
-    vec
-}
-
-fn encode_term_quad(t1: EncodedTerm, t2: EncodedTerm, t3: EncodedTerm, t4: EncodedTerm) -> Vec<u8> {
-    let mut vec = Vec::with_capacity(4 * WRITTEN_TERM_MAX_SIZE);
-    write_term(&mut vec, t1);
-    write_term(&mut vec, t2);
-    write_term(&mut vec, t3);
-    write_term(&mut vec, t4);
-    vec
-}
-
 struct StaticDBRowIterator {
     iter: DBRawIterator<'static>,
     _db: Arc<DB>, // needed to ensure that DB still lives while iter is used
@@ -1162,96 +1132,6 @@ impl Iterator for DecodingIndexIterator {
     }
 }
 
-fn write_spog_quad(sink: &mut Vec<u8>, quad: &EncodedQuad) {
-    write_term(sink, quad.subject);
-    write_term(sink, quad.predicate);
-    write_term(sink, quad.object);
-    write_term(sink, quad.graph_name);
-}
-
-fn write_posg_quad(sink: &mut Vec<u8>, quad: &EncodedQuad) {
-    write_term(sink, quad.predicate);
-    write_term(sink, quad.object);
-    write_term(sink, quad.subject);
-    write_term(sink, quad.graph_name);
-}
-
-fn write_ospg_quad(sink: &mut Vec<u8>, quad: &EncodedQuad) {
-    write_term(sink, quad.object);
-    write_term(sink, quad.subject);
-    write_term(sink, quad.predicate);
-    write_term(sink, quad.graph_name);
-}
-
-fn write_gspo_quad(sink: &mut Vec<u8>, quad: &EncodedQuad) {
-    write_term(sink, quad.graph_name);
-    write_term(sink, quad.subject);
-    write_term(sink, quad.predicate);
-    write_term(sink, quad.object);
-}
-
-fn write_gpos_quad(sink: &mut Vec<u8>, quad: &EncodedQuad) {
-    write_term(sink, quad.graph_name);
-    write_term(sink, quad.predicate);
-    write_term(sink, quad.object);
-    write_term(sink, quad.subject);
-}
-
-fn write_gosp_quad(sink: &mut Vec<u8>, quad: &EncodedQuad) {
-    write_term(sink, quad.graph_name);
-    write_term(sink, quad.object);
-    write_term(sink, quad.subject);
-    write_term(sink, quad.predicate);
-}
-
-fn write_spo_quad(sink: &mut Vec<u8>, quad: &EncodedQuad) {
-    write_term(sink, quad.subject);
-    write_term(sink, quad.predicate);
-    write_term(sink, quad.object);
-}
-
-fn write_pos_quad(sink: &mut Vec<u8>, quad: &EncodedQuad) {
-    write_term(sink, quad.predicate);
-    write_term(sink, quad.object);
-    write_term(sink, quad.subject);
-}
-
-fn write_osp_quad(sink: &mut Vec<u8>, quad: &EncodedQuad) {
-    write_term(sink, quad.object);
-    write_term(sink, quad.subject);
-    write_term(sink, quad.predicate);
-}
-
-#[derive(Clone, Copy)]
-enum QuadEncoding {
-    SPOG,
-    POSG,
-    OSPG,
-    GSPO,
-    GPOS,
-    GOSP,
-    DSPO,
-    DPOS,
-    DOSP,
-}
-
-impl QuadEncoding {
-    fn decode(self, buffer: &[u8]) -> Result<EncodedQuad, io::Error> {
-        let mut cursor = Cursor::new(&buffer);
-        match self {
-            QuadEncoding::SPOG => cursor.read_spog_quad(),
-            QuadEncoding::POSG => cursor.read_posg_quad(),
-            QuadEncoding::OSPG => cursor.read_ospg_quad(),
-            QuadEncoding::GSPO => cursor.read_gspo_quad(),
-            QuadEncoding::GPOS => cursor.read_gpos_quad(),
-            QuadEncoding::GOSP => cursor.read_gosp_quad(),
-            QuadEncoding::DSPO => cursor.read_dspo_quad(),
-            QuadEncoding::DPOS => cursor.read_dpos_quad(),
-            QuadEncoding::DOSP => cursor.read_dosp_quad(),
-        }
-    }
-}
-
 fn map_err(e: Error) -> io::Error {
     io::Error::new(io::ErrorKind::Other, e)
 }
@@ -1330,6 +1210,7 @@ fn store() -> Result<(), io::Error> {
             store.insert(t)?;
         }
 
+        assert_eq!(store.len(), 4);
         assert_eq!(
             store
                 .quads_for_pattern(None, None, None, None)
@@ -1464,7 +1345,7 @@ fn store() -> Result<(), io::Error> {
                     Some(GraphNameRef::DefaultGraph)
                 )
                 .collect::<Result<Vec<_>, _>>()?,
-            vec![default_quad.clone()]
+            vec![default_quad]
         );
         assert_eq!(
             store
@@ -1475,7 +1356,7 @@ fn store() -> Result<(), io::Error> {
                     Some(main_g.as_ref())
                 )
                 .collect::<Result<Vec<_>, _>>()?,
-            vec![named_quad.clone()]
+            vec![named_quad]
         );
     }
 

lib/src/store/sled.rs

@@ -4,9 +4,9 @@ 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::binary_encoder::*;
 use crate::store::numeric_encoder::{
-    write_term, Decoder, ReadEncoder, StrContainer, StrHash, StrLookup, TermReader, WithStoreError,
-    WriteEncoder, WRITTEN_TERM_MAX_SIZE,
+    Decoder, ReadEncoder, StrContainer, StrLookup, WithStoreError, WriteEncoder,
 };
 use crate::store::{
     dump_dataset, dump_graph, get_encoded_quad_pattern, load_dataset, load_graph,
@@ -19,7 +19,7 @@ use sled::transaction::{
 use sled::{Config, Iter, Tree};
 use std::convert::TryInto;
 use std::error::Error;
-use std::io::{BufRead, Cursor, Write};
+use std::io::{BufRead, Write};
 use std::iter::{once, Once};
 use std::path::Path;
 use std::{fmt, io, str};
@@ -62,15 +62,17 @@ use std::{fmt, io, str};
 #[derive(Clone)]
 pub struct SledStore {
     id2str: Tree,
-    quads: Tree,
+    spog: Tree,
+    posg: Tree,
+    ospg: Tree,
+    gspo: Tree,
+    gpos: Tree,
+    gosp: Tree,
+    dspo: Tree,
+    dpos: Tree,
+    dosp: Tree,
 }
 
-const SPOG_PREFIX: u8 = 1;
-const POSG_PREFIX: u8 = 2;
-const OSPG_PREFIX: u8 = 3;
-const GSPO_PREFIX: u8 = 4;
-const GPOS_PREFIX: u8 = 5;
-const GOSP_PREFIX: u8 = 6;
 type EncodedTerm = crate::store::numeric_encoder::EncodedTerm<StrHash>;
 type EncodedQuad = crate::store::numeric_encoder::EncodedQuad<StrHash>;
 
@@ -91,7 +93,15 @@ impl SledStore {
         let db = config.open()?;
         Ok(Self {
             id2str: db.open_tree("id2str")?,
-            quads: db.open_tree("quads")?,
+            spog: db.open_tree("spog")?,
+            posg: db.open_tree("posg")?,
+            ospg: db.open_tree("ospg")?,
+            gspo: db.open_tree("gspo")?,
+            gpos: db.open_tree("gpos")?,
+            gosp: db.open_tree("gosp")?,
+            dspo: db.open_tree("dspo")?,
+            dpos: db.open_tree("dpos")?,
+            dosp: db.open_tree("dosp")?,
         })
     }
 
@@ -154,12 +164,12 @@ impl SledStore {
     ///
     /// Warning: this function executes a full scan
     pub fn len(&self) -> usize {
-        self.quads.len() / 6
+        self.gspo.len() + self.dspo.len()
     }
 
     /// Returns if the store is empty
     pub fn is_empty(&self) -> bool {
-        self.quads.is_empty()
+        self.gspo.is_empty() && self.dspo.is_empty()
     }
 
     /// Executes an ACID transaction.
@@ -193,8 +203,34 @@ impl SledStore {
         &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 })?))?)
+        Ok((
+            &self.id2str,
+            &self.spog,
+            &self.posg,
+            &self.ospg,
+            &self.gspo,
+            &self.gpos,
+            &self.gosp,
+            &self.dspo,
+            &self.dpos,
+            &self.dosp,
+        )
+            .transaction(
+                move |(id2str, spog, posg, ospg, gspo, gpos, gosp, dspo, dpos, dosp)| {
+                    Ok(f(SledTransaction {
+                        id2str,
+                        spog,
+                        posg,
+                        ospg,
+                        gspo,
+                        gpos,
+                        gosp,
+                        dspo,
+                        dpos,
+                        dosp,
+                    })?)
+                },
+            )?)
     }
 
     /// Loads a graph file (i.e. triples) into the store
@@ -301,24 +337,37 @@ impl SledStore {
 
     fn contains_encoded(&self, quad: &EncodedQuad) -> Result<bool, io::Error> {
         let mut buffer = Vec::with_capacity(4 * WRITTEN_TERM_MAX_SIZE);
-        write_spog_quad(&mut buffer, quad);
-        Ok(self.quads.contains_key(buffer)?)
+        if quad.graph_name.is_default_graph() {
+            write_spo_quad(&mut buffer, quad);
+            Ok(self.dspo.contains_key(buffer)?)
+        } else {
+            write_gspo_quad(&mut buffer, quad);
+            Ok(self.gspo.contains_key(buffer)?)
         }
-
-    fn quads(&self) -> DecodingQuadIterator {
-        self.inner_quads(&[SPOG_PREFIX])
+    }
+    fn quads(&self) -> DecodingQuadsIterator {
+        DecodingQuadsIterator::pair(
+            self.dspo_quads(Vec::default()),
+            self.gspo_quads(Vec::default()),
+        )
     }
 
-    fn quads_for_subject(&self, subject: EncodedTerm) -> DecodingQuadIterator {
-        self.inner_quads(encode_term(SPOG_PREFIX, subject))
+    fn quads_for_subject(&self, subject: EncodedTerm) -> DecodingQuadsIterator {
+        DecodingQuadsIterator::pair(
+            self.dspo_quads(encode_term(subject)),
+            self.spog_quads(encode_term(subject)),
+        )
     }
 
     fn quads_for_subject_predicate(
         &self,
         subject: EncodedTerm,
         predicate: EncodedTerm,
-    ) -> DecodingQuadIterator {
-        self.inner_quads(encode_term_pair(SPOG_PREFIX, subject, predicate))
+    ) -> DecodingQuadsIterator {
+        DecodingQuadsIterator::pair(
+            self.dspo_quads(encode_term_pair(subject, predicate)),
+            self.spog_quads(encode_term_pair(subject, predicate)),
+        )
     }
 
     fn quads_for_subject_predicate_object(
@@ -326,44 +375,67 @@ impl SledStore {
         subject: EncodedTerm,
         predicate: EncodedTerm,
         object: EncodedTerm,
-    ) -> DecodingQuadIterator {
-        self.inner_quads(encode_term_triple(SPOG_PREFIX, subject, predicate, object))
+    ) -> DecodingQuadsIterator {
+        DecodingQuadsIterator::pair(
+            self.dspo_quads(encode_term_triple(subject, predicate, object)),
+            self.spog_quads(encode_term_triple(subject, predicate, object)),
+        )
     }
 
     fn quads_for_subject_object(
         &self,
         subject: EncodedTerm,
         object: EncodedTerm,
-    ) -> DecodingQuadIterator {
-        self.inner_quads(encode_term_pair(OSPG_PREFIX, object, subject))
+    ) -> DecodingQuadsIterator {
+        DecodingQuadsIterator::pair(
+            self.dosp_quads(encode_term_pair(object, subject)),
+            self.ospg_quads(encode_term_pair(object, subject)),
+        )
     }
 
-    fn quads_for_predicate(&self, predicate: EncodedTerm) -> DecodingQuadIterator {
-        self.inner_quads(encode_term(POSG_PREFIX, predicate))
+    fn quads_for_predicate(&self, predicate: EncodedTerm) -> DecodingQuadsIterator {
+        DecodingQuadsIterator::pair(
+            self.dpos_quads(encode_term(predicate)),
+            self.posg_quads(encode_term(predicate)),
+        )
     }
 
     fn quads_for_predicate_object(
         &self,
         predicate: EncodedTerm,
         object: EncodedTerm,
-    ) -> DecodingQuadIterator {
-        self.inner_quads(encode_term_pair(POSG_PREFIX, predicate, object))
+    ) -> DecodingQuadsIterator {
+        DecodingQuadsIterator::pair(
+            self.dpos_quads(encode_term_pair(predicate, object)),
+            self.posg_quads(encode_term_pair(predicate, object)),
+        )
     }
 
-    fn quads_for_object(&self, object: EncodedTerm) -> DecodingQuadIterator {
-        self.inner_quads(encode_term(OSPG_PREFIX, object))
+    fn quads_for_object(&self, object: EncodedTerm) -> DecodingQuadsIterator {
+        DecodingQuadsIterator::pair(
+            self.dosp_quads(encode_term(object)),
+            self.ospg_quads(encode_term(object)),
+        )
     }
 
-    fn quads_for_graph(&self, graph_name: EncodedTerm) -> DecodingQuadIterator {
-        self.inner_quads(encode_term(GSPO_PREFIX, graph_name))
+    fn quads_for_graph(&self, graph_name: EncodedTerm) -> DecodingQuadsIterator {
+        DecodingQuadsIterator::new(if graph_name.is_default_graph() {
+            self.dspo_quads(Vec::default())
+        } else {
+            self.gspo_quads(encode_term(graph_name))
+        })
     }
 
     fn quads_for_subject_graph(
         &self,
         subject: EncodedTerm,
         graph_name: EncodedTerm,
-    ) -> DecodingQuadIterator {
-        self.inner_quads(encode_term_pair(GSPO_PREFIX, graph_name, subject))
+    ) -> DecodingQuadsIterator {
+        DecodingQuadsIterator::new(if graph_name.is_default_graph() {
+            self.dspo_quads(encode_term(subject))
+        } else {
+            self.gspo_quads(encode_term_pair(graph_name, subject))
+        })
     }
 
     fn quads_for_subject_predicate_graph(
@@ -371,13 +443,26 @@ impl SledStore {
         subject: EncodedTerm,
         predicate: EncodedTerm,
         graph_name: EncodedTerm,
-    ) -> DecodingQuadIterator {
-        self.inner_quads(encode_term_triple(
-            GSPO_PREFIX,
-            graph_name,
-            subject,
-            predicate,
-        ))
+    ) -> DecodingQuadsIterator {
+        DecodingQuadsIterator::new(if graph_name.is_default_graph() {
+            self.dspo_quads(encode_term_pair(subject, predicate))
+        } else {
+            self.gspo_quads(encode_term_triple(graph_name, subject, predicate))
+        })
+    }
+
+    fn quads_for_subject_predicate_object_graph(
+        &self,
+        subject: EncodedTerm,
+        predicate: EncodedTerm,
+        object: EncodedTerm,
+        graph_name: EncodedTerm,
+    ) -> DecodingQuadsIterator {
+        DecodingQuadsIterator::new(if graph_name.is_default_graph() {
+            self.dspo_quads(encode_term_triple(subject, predicate, object))
+        } else {
+            self.gspo_quads(encode_term_quad(graph_name, subject, predicate, object))
+        })
     }
 
     fn quads_for_subject_object_graph(
@@ -385,16 +470,24 @@ impl SledStore {
         subject: EncodedTerm,
         object: EncodedTerm,
         graph_name: EncodedTerm,
-    ) -> DecodingQuadIterator {
-        self.inner_quads(encode_term_triple(GOSP_PREFIX, graph_name, object, subject))
+    ) -> DecodingQuadsIterator {
+        DecodingQuadsIterator::new(if graph_name.is_default_graph() {
+            self.dosp_quads(encode_term_pair(object, subject))
+        } else {
+            self.gosp_quads(encode_term_triple(graph_name, object, subject))
+        })
     }
 
     fn quads_for_predicate_graph(
         &self,
         predicate: EncodedTerm,
         graph_name: EncodedTerm,
-    ) -> DecodingQuadIterator {
-        self.inner_quads(encode_term_pair(GPOS_PREFIX, graph_name, predicate))
+    ) -> DecodingQuadsIterator {
+        DecodingQuadsIterator::new(if graph_name.is_default_graph() {
+            self.dpos_quads(encode_term(predicate))
+        } else {
+            self.gpos_quads(encode_term_pair(graph_name, predicate))
+        })
     }
 
     fn quads_for_predicate_object_graph(
@@ -402,26 +495,71 @@ impl SledStore {
         predicate: EncodedTerm,
         object: EncodedTerm,
         graph_name: EncodedTerm,
-    ) -> DecodingQuadIterator {
-        self.inner_quads(encode_term_triple(
-            GPOS_PREFIX,
-            graph_name,
-            predicate,
-            object,
-        ))
+    ) -> DecodingQuadsIterator {
+        DecodingQuadsIterator::new(if graph_name.is_default_graph() {
+            self.dpos_quads(encode_term_pair(predicate, object))
+        } else {
+            self.gpos_quads(encode_term_triple(graph_name, predicate, object))
+        })
     }
 
     fn quads_for_object_graph(
         &self,
         object: EncodedTerm,
         graph_name: EncodedTerm,
-    ) -> DecodingQuadIterator {
-        self.inner_quads(encode_term_pair(GPOS_PREFIX, graph_name, object))
+    ) -> DecodingQuadsIterator {
+        DecodingQuadsIterator::new(if graph_name.is_default_graph() {
+            self.dosp_quads(encode_term(object))
+        } else {
+            self.gosp_quads(encode_term_pair(graph_name, object))
+        })
+    }
+
+    fn spog_quads(&self, prefix: Vec<u8>) -> DecodingQuadIterator {
+        self.inner_quads(&self.spog, prefix, QuadEncoding::SPOG)
+    }
+
+    fn posg_quads(&self, prefix: Vec<u8>) -> DecodingQuadIterator {
+        self.inner_quads(&self.posg, prefix, QuadEncoding::POSG)
+    }
+
+    fn ospg_quads(&self, prefix: Vec<u8>) -> DecodingQuadIterator {
+        self.inner_quads(&self.ospg, prefix, QuadEncoding::OSPG)
+    }
+
+    fn gspo_quads(&self, prefix: Vec<u8>) -> DecodingQuadIterator {
+        self.inner_quads(&self.gspo, prefix, QuadEncoding::GSPO)
+    }
+
+    fn gpos_quads(&self, prefix: Vec<u8>) -> DecodingQuadIterator {
+        self.inner_quads(&self.gpos, prefix, QuadEncoding::GPOS)
+    }
+
+    fn gosp_quads(&self, prefix: Vec<u8>) -> DecodingQuadIterator {
+        self.inner_quads(&self.gosp, prefix, QuadEncoding::GOSP)
     }
 
-    fn inner_quads(&self, prefix: impl AsRef<[u8]>) -> DecodingQuadIterator {
+    fn dspo_quads(&self, prefix: Vec<u8>) -> DecodingQuadIterator {
+        self.inner_quads(&self.dspo, prefix, QuadEncoding::DSPO)
+    }
+
+    fn dpos_quads(&self, prefix: Vec<u8>) -> DecodingQuadIterator {
+        self.inner_quads(&self.dpos, prefix, QuadEncoding::DPOS)
+    }
+
+    fn dosp_quads(&self, prefix: Vec<u8>) -> DecodingQuadIterator {
+        self.inner_quads(&self.dosp, prefix, QuadEncoding::DOSP)
+    }
+
+    fn inner_quads(
+        &self,
+        tree: &Tree,
+        prefix: impl AsRef<[u8]>,
+        encoding: QuadEncoding,
+    ) -> DecodingQuadIterator {
         DecodingQuadIterator {
-            iter: self.quads.scan_prefix(prefix),
+            iter: tree.scan_prefix(prefix),
+            encoding,
         }
     }
 }
@@ -460,7 +598,7 @@ impl StrLookup for SledStore {
 }
 
 impl ReadableEncodedStore for SledStore {
-    type QuadsIter = DecodingQuadIterator;
+    type QuadsIter = DecodingQuadsIterator;
 
     fn encoded_quads_for_pattern(
         &self,
@@ -468,18 +606,14 @@ impl ReadableEncodedStore for SledStore {
         predicate: Option<EncodedTerm>,
         object: Option<EncodedTerm>,
         graph_name: Option<EncodedTerm>,
-    ) -> DecodingQuadIterator {
+    ) -> DecodingQuadsIterator {
         match subject {
             Some(subject) => match predicate {
                 Some(predicate) => match object {
                     Some(object) => match graph_name {
-                        Some(graph_name) => self.inner_quads(encode_term_quad(
-                            SPOG_PREFIX,
-                            subject,
-                            predicate,
-                            object,
-                            graph_name,
-                        )),
+                        Some(graph_name) => self.quads_for_subject_predicate_object_graph(
+                            subject, predicate, object, graph_name,
+                        ),
                         None => self.quads_for_subject_predicate_object(subject, predicate, object),
                     },
                     None => match graph_name {
@@ -542,29 +676,43 @@ impl<'a> WritableEncodedStore for &'a SledStore {
     fn insert_encoded(&mut self, quad: &EncodedQuad) -> Result<(), io::Error> {
         let mut buffer = Vec::with_capacity(4 * WRITTEN_TERM_MAX_SIZE + 1);
 
+        if quad.graph_name.is_default_graph() {
+            write_spo_quad(&mut buffer, quad);
+            self.dspo.insert(buffer.as_slice(), &[])?;
+            buffer.clear();
+
+            write_pos_quad(&mut buffer, quad);
+            self.dpos.insert(buffer.as_slice(), &[])?;
+            buffer.clear();
+
+            write_osp_quad(&mut buffer, quad);
+            self.dosp.insert(buffer.as_slice(), &[])?;
+            buffer.clear();
+        } else {
             write_spog_quad(&mut buffer, quad);
-        self.quads.insert(buffer.as_slice(), &[])?;
+            self.spog.insert(buffer.as_slice(), &[])?;
             buffer.clear();
 
             write_posg_quad(&mut buffer, quad);
-        self.quads.insert(buffer.as_slice(), &[])?;
+            self.posg.insert(buffer.as_slice(), &[])?;
             buffer.clear();
 
             write_ospg_quad(&mut buffer, quad);
-        self.quads.insert(buffer.as_slice(), &[])?;
+            self.ospg.insert(buffer.as_slice(), &[])?;
             buffer.clear();
 
             write_gspo_quad(&mut buffer, quad);
-        self.quads.insert(buffer.as_slice(), &[])?;
+            self.gspo.insert(buffer.as_slice(), &[])?;
             buffer.clear();
 
             write_gpos_quad(&mut buffer, quad);
-        self.quads.insert(buffer.as_slice(), &[])?;
+            self.gpos.insert(buffer.as_slice(), &[])?;
             buffer.clear();
 
             write_gosp_quad(&mut buffer, quad);
-        self.quads.insert(buffer.as_slice(), &[])?;
+            self.gosp.insert(buffer.as_slice(), &[])?;
             buffer.clear();
+        }
 
         Ok(())
     }
@@ -572,29 +720,43 @@ impl<'a> WritableEncodedStore for &'a SledStore {
     fn remove_encoded(&mut self, quad: &EncodedQuad) -> Result<(), io::Error> {
         let mut buffer = Vec::with_capacity(4 * WRITTEN_TERM_MAX_SIZE + 1);
 
+        if quad.graph_name.is_default_graph() {
+            write_spo_quad(&mut buffer, quad);
+            self.dspo.remove(buffer.as_slice())?;
+            buffer.clear();
+
+            write_pos_quad(&mut buffer, quad);
+            self.dpos.remove(buffer.as_slice())?;
+            buffer.clear();
+
+            write_osp_quad(&mut buffer, quad);
+            self.dosp.remove(buffer.as_slice())?;
+            buffer.clear();
+        } else {
             write_spog_quad(&mut buffer, quad);
-        self.quads.remove(buffer.as_slice())?;
+            self.spog.remove(buffer.as_slice())?;
             buffer.clear();
 
             write_posg_quad(&mut buffer, quad);
-        self.quads.remove(buffer.as_slice())?;
+            self.posg.remove(buffer.as_slice())?;
             buffer.clear();
 
             write_ospg_quad(&mut buffer, quad);
-        self.quads.remove(buffer.as_slice())?;
+            self.ospg.remove(buffer.as_slice())?;
             buffer.clear();
 
             write_gspo_quad(&mut buffer, quad);
-        self.quads.remove(buffer.as_slice())?;
+            self.gspo.remove(buffer.as_slice())?;
             buffer.clear();
 
             write_gpos_quad(&mut buffer, quad);
-        self.quads.remove(buffer.as_slice())?;
+            self.gpos.remove(buffer.as_slice())?;
             buffer.clear();
 
             write_gosp_quad(&mut buffer, quad);
-        self.quads.remove(buffer.as_slice())?;
+            self.gosp.remove(buffer.as_slice())?;
             buffer.clear();
+        }
 
         Ok(())
     }
@@ -602,8 +764,16 @@ impl<'a> WritableEncodedStore for &'a SledStore {
 
 /// Allows inserting and deleting quads during an ACID transaction with the [`SledStore`](struct.SledStore.html).
 pub struct SledTransaction<'a> {
-    quads: &'a TransactionalTree,
     id2str: &'a TransactionalTree,
+    spog: &'a TransactionalTree,
+    posg: &'a TransactionalTree,
+    ospg: &'a TransactionalTree,
+    gspo: &'a TransactionalTree,
+    gpos: &'a TransactionalTree,
+    gosp: &'a TransactionalTree,
+    dspo: &'a TransactionalTree,
+    dpos: &'a TransactionalTree,
+    dosp: &'a TransactionalTree,
 }
 
 impl SledTransaction<'_> {
@@ -721,29 +891,43 @@ impl<'a> WritableEncodedStore for &'a SledTransaction<'a> {
     ) -> Result<(), SledUnabortableTransactionError> {
         let mut buffer = Vec::with_capacity(4 * WRITTEN_TERM_MAX_SIZE + 1);
 
+        if quad.graph_name.is_default_graph() {
+            write_spo_quad(&mut buffer, quad);
+            self.dspo.insert(buffer.as_slice(), &[])?;
+            buffer.clear();
+
+            write_pos_quad(&mut buffer, quad);
+            self.dpos.insert(buffer.as_slice(), &[])?;
+            buffer.clear();
+
+            write_osp_quad(&mut buffer, quad);
+            self.dosp.insert(buffer.as_slice(), &[])?;
+            buffer.clear();
+        } else {
             write_spog_quad(&mut buffer, quad);
-        self.quads.insert(buffer.as_slice(), &[])?;
+            self.spog.insert(buffer.as_slice(), &[])?;
             buffer.clear();
 
             write_posg_quad(&mut buffer, quad);
-        self.quads.insert(buffer.as_slice(), &[])?;
+            self.posg.insert(buffer.as_slice(), &[])?;
             buffer.clear();
 
             write_ospg_quad(&mut buffer, quad);
-        self.quads.insert(buffer.as_slice(), &[])?;
+            self.ospg.insert(buffer.as_slice(), &[])?;
             buffer.clear();
 
             write_gspo_quad(&mut buffer, quad);
-        self.quads.insert(buffer.as_slice(), &[])?;
+            self.gspo.insert(buffer.as_slice(), &[])?;
             buffer.clear();
 
             write_gpos_quad(&mut buffer, quad);
-        self.quads.insert(buffer.as_slice(), &[])?;
+            self.gpos.insert(buffer.as_slice(), &[])?;
             buffer.clear();
 
             write_gosp_quad(&mut buffer, quad);
-        self.quads.insert(buffer.as_slice(), &[])?;
+            self.gosp.insert(buffer.as_slice(), &[])?;
             buffer.clear();
+        }
 
         Ok(())
     }
@@ -754,29 +938,43 @@ impl<'a> WritableEncodedStore for &'a SledTransaction<'a> {
     ) -> Result<(), SledUnabortableTransactionError> {
         let mut buffer = Vec::with_capacity(4 * WRITTEN_TERM_MAX_SIZE + 1);
 
+        if quad.graph_name.is_default_graph() {
+            write_spo_quad(&mut buffer, quad);
+            self.dspo.remove(buffer.as_slice())?;
+            buffer.clear();
+
+            write_pos_quad(&mut buffer, quad);
+            self.dpos.remove(buffer.as_slice())?;
+            buffer.clear();
+
+            write_osp_quad(&mut buffer, quad);
+            self.dosp.remove(buffer.as_slice())?;
+            buffer.clear();
+        } else {
             write_spog_quad(&mut buffer, quad);
-        self.quads.remove(buffer.as_slice())?;
+            self.spog.remove(buffer.as_slice())?;
             buffer.clear();
 
             write_posg_quad(&mut buffer, quad);
-        self.quads.remove(buffer.as_slice())?;
+            self.posg.remove(buffer.as_slice())?;
             buffer.clear();
 
             write_ospg_quad(&mut buffer, quad);
-        self.quads.remove(buffer.as_slice())?;
+            self.ospg.remove(buffer.as_slice())?;
             buffer.clear();
 
             write_gspo_quad(&mut buffer, quad);
-        self.quads.remove(buffer.as_slice())?;
+            self.gspo.remove(buffer.as_slice())?;
             buffer.clear();
 
             write_gpos_quad(&mut buffer, quad);
-        self.quads.remove(buffer.as_slice())?;
+            self.gpos.remove(buffer.as_slice())?;
             buffer.clear();
 
             write_gosp_quad(&mut buffer, quad);
-        self.quads.remove(buffer.as_slice())?;
+            self.gosp.remove(buffer.as_slice())?;
             buffer.clear();
+        }
 
         Ok(())
     }
@@ -937,48 +1135,44 @@ impl SledPreparedQuery {
     }
 }
 
-fn encode_term(prefix: u8, t: EncodedTerm) -> Vec<u8> {
-    let mut vec = Vec::with_capacity(WRITTEN_TERM_MAX_SIZE + 1);
-    vec.push(prefix);
-    write_term(&mut vec, t);
-    vec
+pub(crate) struct DecodingQuadsIterator {
+    first: DecodingQuadIterator,
+    second: Option<DecodingQuadIterator>,
 }
 
-fn encode_term_pair(prefix: u8, t1: EncodedTerm, t2: EncodedTerm) -> Vec<u8> {
-    let mut vec = Vec::with_capacity(2 * WRITTEN_TERM_MAX_SIZE + 1);
-    vec.push(prefix);
-    write_term(&mut vec, t1);
-    write_term(&mut vec, t2);
-    vec
-}
+impl DecodingQuadsIterator {
+    fn new(first: DecodingQuadIterator) -> Self {
+        Self {
+            first,
+            second: None,
+        }
+    }
 
-fn encode_term_triple(prefix: u8, t1: EncodedTerm, t2: EncodedTerm, t3: EncodedTerm) -> Vec<u8> {
-    let mut vec = Vec::with_capacity(3 * WRITTEN_TERM_MAX_SIZE + 1);
-    vec.push(prefix);
-    write_term(&mut vec, t1);
-    write_term(&mut vec, t2);
-    write_term(&mut vec, t3);
-    vec
+    fn pair(first: DecodingQuadIterator, second: DecodingQuadIterator) -> Self {
+        Self {
+            first,
+            second: Some(second),
+        }
+    }
 }
 
-fn encode_term_quad(
-    prefix: u8,
-    t1: EncodedTerm,
-    t2: EncodedTerm,
-    t3: EncodedTerm,
-    t4: EncodedTerm,
-) -> Vec<u8> {
-    let mut vec = Vec::with_capacity(4 * WRITTEN_TERM_MAX_SIZE + 1);
-    vec.push(prefix);
-    write_term(&mut vec, t1);
-    write_term(&mut vec, t2);
-    write_term(&mut vec, t3);
-    write_term(&mut vec, t4);
-    vec
+impl Iterator for DecodingQuadsIterator {
+    type Item = Result<EncodedQuad, io::Error>;
+
+    fn next(&mut self) -> Option<Result<EncodedQuad, io::Error>> {
+        if let Some(result) = self.first.next() {
+            Some(result)
+        } else if let Some(second) = self.second.as_mut() {
+            second.next()
+        } else {
+            None
+        }
+    }
 }
 
 pub(crate) struct DecodingQuadIterator {
     iter: Iter,
+    encoding: QuadEncoding,
 }
 
 impl Iterator for DecodingQuadIterator {
@@ -986,79 +1180,15 @@ impl Iterator for DecodingQuadIterator {
 
     fn next(&mut self) -> Option<Result<EncodedQuad, io::Error>> {
         Some(match self.iter.next()? {
-            Ok((encoded, _)) => decode_quad(&encoded),
+            Ok((encoded, _)) => self.encoding.decode(&encoded),
             Err(error) => Err(error.into()),
         })
     }
 }
 
-fn write_spog_quad(sink: &mut Vec<u8>, quad: &EncodedQuad) {
-    sink.push(SPOG_PREFIX);
-    write_term(sink, quad.subject);
-    write_term(sink, quad.predicate);
-    write_term(sink, quad.object);
-    write_term(sink, quad.graph_name);
-}
-
-fn write_posg_quad(sink: &mut Vec<u8>, quad: &EncodedQuad) {
-    sink.push(POSG_PREFIX);
-    write_term(sink, quad.predicate);
-    write_term(sink, quad.object);
-    write_term(sink, quad.subject);
-    write_term(sink, quad.graph_name);
-}
-
-fn write_ospg_quad(sink: &mut Vec<u8>, quad: &EncodedQuad) {
-    sink.push(OSPG_PREFIX);
-    write_term(sink, quad.object);
-    write_term(sink, quad.subject);
-    write_term(sink, quad.predicate);
-    write_term(sink, quad.graph_name);
-}
-
-fn write_gspo_quad(sink: &mut Vec<u8>, quad: &EncodedQuad) {
-    sink.push(GSPO_PREFIX);
-    write_term(sink, quad.graph_name);
-    write_term(sink, quad.subject);
-    write_term(sink, quad.predicate);
-    write_term(sink, quad.object);
-}
-
-fn write_gpos_quad(sink: &mut Vec<u8>, quad: &EncodedQuad) {
-    sink.push(GPOS_PREFIX);
-    write_term(sink, quad.graph_name);
-    write_term(sink, quad.predicate);
-    write_term(sink, quad.object);
-    write_term(sink, quad.subject);
-}
-
-fn write_gosp_quad(sink: &mut Vec<u8>, quad: &EncodedQuad) {
-    sink.push(GOSP_PREFIX);
-    write_term(sink, quad.graph_name);
-    write_term(sink, quad.object);
-    write_term(sink, quad.subject);
-    write_term(sink, quad.predicate);
-}
-
-fn decode_quad(encoded: &[u8]) -> Result<EncodedQuad, io::Error> {
-    let mut cursor = Cursor::new(&encoded[1..]);
-    match encoded[0] {
-        SPOG_PREFIX => Ok(cursor.read_spog_quad()?),
-        POSG_PREFIX => Ok(cursor.read_posg_quad()?),
-        OSPG_PREFIX => Ok(cursor.read_ospg_quad()?),
-        GSPO_PREFIX => Ok(cursor.read_gspo_quad()?),
-        GPOS_PREFIX => Ok(cursor.read_gpos_quad()?),
-        GOSP_PREFIX => Ok(cursor.read_gosp_quad()?),
-        _ => Err(invalid_data_error(format!(
-            "Invalid quad type identifier: {}",
-            encoded[0]
-        ))),
-    }
-}
-
 enum QuadsIter {
     Quads {
-        iter: DecodingQuadIterator,
+        iter: DecodingQuadsIterator,
         store: SledStore,
     },
     Error(Once<io::Error>),
@@ -1087,38 +1217,60 @@ fn store() -> Result<(), io::Error> {
     let main_s = NamedOrBlankNode::from(BlankNode::default());
     let main_p = NamedNode::new("http://example.com").unwrap();
     let main_o = Term::from(Literal::from(1));
-
-    let main_quad = Quad::new(main_s.clone(), main_p.clone(), main_o.clone(), None);
-    let all_o = vec![
+    let main_g = GraphName::from(BlankNode::default());
+
+    let default_quad = Quad::new(main_s.clone(), main_p.clone(), main_o.clone(), None);
+    let named_quad = Quad::new(
+        main_s.clone(),
+        main_p.clone(),
+        main_o.clone(),
+        main_g.clone(),
+    );
+    let default_quads = vec![
+        Quad::new(main_s.clone(), main_p.clone(), Literal::from(0), None),
+        default_quad.clone(),
+        Quad::new(
+            main_s.clone(),
+            main_p.clone(),
+            Literal::from(200000000),
+            None,
+        ),
+    ];
+    let all_quads = vec![
         Quad::new(main_s.clone(), main_p.clone(), Literal::from(0), None),
-        Quad::new(main_s.clone(), main_p.clone(), main_o.clone(), None),
-        Quad::new(main_s.clone(), main_p.clone(), Literal::from(2), None),
+        default_quad.clone(),
+        Quad::new(
+            main_s.clone(),
+            main_p.clone(),
+            Literal::from(200000000),
+            None,
+        ),
+        named_quad.clone(),
     ];
 
     let store = SledStore::new()?;
-    store.insert(&main_quad)?;
-    for t in &all_o {
+    for t in &all_quads {
         store.insert(t)?;
     }
 
-    let target = vec![main_quad];
+    assert_eq!(store.len(), 4);
     assert_eq!(
         store
             .quads_for_pattern(None, None, None, None)
             .collect::<Result<Vec<_>, _>>()?,
-        all_o
+        all_quads
     );
     assert_eq!(
         store
             .quads_for_pattern(Some(main_s.as_ref()), None, None, None)
             .collect::<Result<Vec<_>, _>>()?,
-        all_o
+        all_quads
     );
     assert_eq!(
         store
             .quads_for_pattern(Some(main_s.as_ref()), Some(main_p.as_ref()), None, None)
             .collect::<Result<Vec<_>, _>>()?,
-        all_o
+        all_quads
     );
     assert_eq!(
         store
@@ -1129,7 +1281,7 @@ fn store() -> Result<(), io::Error> {
                 None
             )
             .collect::<Result<Vec<_>, _>>()?,
-        target
+        vec![default_quad.clone(), named_quad.clone()]
     );
     assert_eq!(
         store
@@ -1140,7 +1292,18 @@ fn store() -> Result<(), io::Error> {
                 Some(GraphNameRef::DefaultGraph)
             )
             .collect::<Result<Vec<_>, _>>()?,
-        target
+        vec![default_quad.clone()]
+    );
+    assert_eq!(
+        store
+            .quads_for_pattern(
+                Some(main_s.as_ref()),
+                Some(main_p.as_ref()),
+                Some(main_o.as_ref()),
+                Some(main_g.as_ref())
+            )
+            .collect::<Result<Vec<_>, _>>()?,
+        vec![named_quad.clone()]
     );
     assert_eq!(
         store
@@ -1151,13 +1314,13 @@ fn store() -> Result<(), io::Error> {
                 Some(GraphNameRef::DefaultGraph)
             )
             .collect::<Result<Vec<_>, _>>()?,
-        all_o
+        default_quads
     );
     assert_eq!(
         store
             .quads_for_pattern(Some(main_s.as_ref()), None, Some(main_o.as_ref()), None)
             .collect::<Result<Vec<_>, _>>()?,
-        target
+        vec![default_quad.clone(), named_quad.clone()]
     );
     assert_eq!(
         store
@@ -1168,7 +1331,18 @@ fn store() -> Result<(), io::Error> {
                 Some(GraphNameRef::DefaultGraph)
             )
             .collect::<Result<Vec<_>, _>>()?,
-        target
+        vec![default_quad.clone()]
+    );
+    assert_eq!(
+        store
+            .quads_for_pattern(
+                Some(main_s.as_ref()),
+                None,
+                Some(main_o.as_ref()),
+                Some(main_g.as_ref())
+            )
+            .collect::<Result<Vec<_>, _>>()?,
+        vec![named_quad.clone()]
     );
     assert_eq!(
         store
@@ -1179,31 +1353,31 @@ fn store() -> Result<(), io::Error> {
                 Some(GraphNameRef::DefaultGraph)
             )
             .collect::<Result<Vec<_>, _>>()?,
-        all_o
+        default_quads
     );
     assert_eq!(
         store
             .quads_for_pattern(None, Some(main_p.as_ref()), None, None)
             .collect::<Result<Vec<_>, _>>()?,
-        all_o
+        all_quads
     );
     assert_eq!(
         store
             .quads_for_pattern(None, Some(main_p.as_ref()), Some(main_o.as_ref()), None)
             .collect::<Result<Vec<_>, _>>()?,
-        target
+        vec![default_quad.clone(), named_quad.clone()]
     );
     assert_eq!(
         store
             .quads_for_pattern(None, None, Some(main_o.as_ref()), None)
             .collect::<Result<Vec<_>, _>>()?,
-        target
+        vec![default_quad.clone(), named_quad.clone()]
     );
     assert_eq!(
         store
             .quads_for_pattern(None, None, None, Some(GraphNameRef::DefaultGraph))
             .collect::<Result<Vec<_>, _>>()?,
-        all_o
+        default_quads
     );
     assert_eq!(
         store
@@ -1214,7 +1388,18 @@ fn store() -> Result<(), io::Error> {
                 Some(GraphNameRef::DefaultGraph)
             )
             .collect::<Result<Vec<_>, _>>()?,
-        target
+        vec![default_quad]
+    );
+    assert_eq!(
+        store
+            .quads_for_pattern(
+                None,
+                Some(main_p.as_ref()),
+                Some(main_o.as_ref()),
+                Some(main_g.as_ref())
+            )
+            .collect::<Result<Vec<_>, _>>()?,
+        vec![named_quad]
     );
 
     Ok(())