diff --git a/src/io/csv.rs b/src/io/csv.rs
index 7d730d942..6afaf2150 100644
--- a/src/io/csv.rs
+++ b/src/io/csv.rs
@@ -2,7 +2,6 @@
 
 use crate::error::Error;
 use crate::physical::datatypes::{data_value::VecT, DataTypeName};
-use crate::physical::dictionary::Dictionary;
 use csv::Reader;
 
 /// Imports a csv file
@@ -15,7 +14,6 @@ use csv::Reader;
 pub fn read<T>(
     datatypes: &[Option<DataTypeName>],
     csv_reader: &mut Reader<T>,
-    dict: &mut dyn Dictionary,
 ) -> Result<Vec<VecT>, Error>
 where
     T: std::io::Read,
@@ -28,7 +26,6 @@ where
                 DataTypeName::U64 => VecT::U64(Vec::new()),
                 DataTypeName::Float => VecT::Float(Vec::new()),
                 DataTypeName::Double => VecT::Double(Vec::new()),
-                DataTypeName::String => VecT::String(Vec::new()),
             })
         }));
     });
@@ -38,7 +35,7 @@ where
             if let Err(Error::RollBack(rollback)) =
                 row.iter().enumerate().try_for_each(|(idx, item)| {
                     if let Some(datatype) = datatypes[idx] {
-                        match datatype.parse(item, dict) {
+                        match datatype.parse(item) {
                             Ok(val) => {
                                 result[idx].as_mut().map(|vect| {
                                     vect.push(&val);
@@ -70,7 +67,6 @@ where
 #[cfg(test)]
 mod test {
     use super::*;
-    use crate::physical::dictionary::PrefixedStringDictionary;
     use csv::ReaderBuilder;
     use quickcheck_macros::quickcheck;
     use test_log::test;
@@ -85,11 +81,7 @@ Boston;United States;4628910
             .delimiter(b';')
             .from_reader(data.as_bytes());
 
-        let x = read(
-            &[None, None, None],
-            &mut rdr,
-            &mut PrefixedStringDictionary::new(),
-        );
+        let x = read(&[None, None, None], &mut rdr);
         assert!(x.is_ok());
         assert_eq!(x.unwrap().len(), 0);
     }
@@ -100,7 +92,7 @@ Boston;United States;4628910
         let data = "\
 10;20;30;40;20;valid
 asdf;12.2;413;22.3;23;invalid
-node01;22;33.33;12.333332;10;valid again
+node01;22;33.33;12.333332;10;valid
 node02;1312;12.33;313;1431;valid
 node03;123;123;13;55;123;invalid
 ";
@@ -116,40 +108,14 @@ node03;123;123;13;55;123;invalid
                 Some(DataTypeName::Double),
                 Some(DataTypeName::Float),
                 Some(DataTypeName::U64),
-                Some(DataTypeName::String),
+                None,
             ],
             &mut rdr,
-            &mut PrefixedStringDictionary::new(),
         );
 
         assert!(imported.is_ok());
-        assert_eq!(imported.as_ref().unwrap().len(), 5);
+        assert_eq!(imported.as_ref().unwrap().len(), 4);
         assert_eq!(imported.as_ref().unwrap()[0].len(), 3);
-        log::debug!("imported: {:?}", imported);
-        assert_eq!(
-            imported.as_ref().unwrap()[4]
-                .get(0)
-                .map(|v| v.as_string().unwrap()),
-            Some(0usize)
-        );
-        assert_eq!(
-            imported.as_ref().unwrap()[4]
-                .get(1)
-                .map(|v| v.as_string().unwrap()),
-            Some(1usize)
-        );
-        assert_eq!(
-            imported.as_ref().unwrap()[4]
-                .get(2)
-                .map(|v| v.as_string().unwrap()),
-            Some(0usize)
-        );
-        assert_eq!(
-            imported.as_ref().unwrap()[4]
-                .get(3)
-                .map(|v| v.as_string().unwrap()),
-            None
-        );
     }
 
     #[quickcheck]
@@ -190,7 +156,6 @@ node03;123;123;13;55;123;invalid
                 Some(DataTypeName::Float),
             ],
             &mut rdr,
-            &mut PrefixedStringDictionary::new(),
         );
 
         assert!(imported.is_ok());
diff --git a/src/physical/columns/adaptive_column_builder.rs b/src/physical/columns/adaptive_column_builder.rs
index 85e2db500..68079c4e1 100644
--- a/src/physical/columns/adaptive_column_builder.rs
+++ b/src/physical/columns/adaptive_column_builder.rs
@@ -132,8 +132,6 @@ pub enum AdaptiveColumnBuilderT {
     Float(AdaptiveColumnBuilder<Float>),
     /// Case Double
     Double(AdaptiveColumnBuilder<Double>),
-    /// Case String
-    String(AdaptiveColumnBuilder<usize>),
 }
 
 impl AdaptiveColumnBuilderT {
@@ -143,7 +141,6 @@ impl AdaptiveColumnBuilderT {
             DataTypeName::U64 => Self::U64(AdaptiveColumnBuilder::new()),
             DataTypeName::Float => Self::Float(AdaptiveColumnBuilder::new()),
             DataTypeName::Double => Self::Double(AdaptiveColumnBuilder::new()),
-            DataTypeName::String => Self::String(AdaptiveColumnBuilder::new()),
         }
     }
 
@@ -171,13 +168,6 @@ impl AdaptiveColumnBuilderT {
                     panic!("value does not match AdaptiveColumn type");
                 }
             }
-            Self::String(cb) => {
-                cb.add(
-                    value
-                        .as_string()
-                        .expect("Value does not match AdaptiveColumn type"),
-                );
-            }
         }
     }
 
@@ -187,7 +177,6 @@ impl AdaptiveColumnBuilderT {
             Self::U64(cb) => cb.count(),
             Self::Float(cb) => cb.count(),
             Self::Double(cb) => cb.count(),
-            Self::String(cb) => cb.count(),
         }
     }
 }
diff --git a/src/physical/columns/column.rs b/src/physical/columns/column.rs
index 688652824..87ca5c737 100644
--- a/src/physical/columns/column.rs
+++ b/src/physical/columns/column.rs
@@ -80,8 +80,6 @@ pub enum ColumnT {
     Float(ColumnEnum<Float>),
     /// Case ColumnEnum<Double>
     Double(ColumnEnum<Double>),
-    /// Case ColumnEnum<String>
-    String(ColumnEnum<usize>),
 }
 
 generate_datatype_forwarder!(forward_to_column_enum);
diff --git a/src/physical/columns/interval_column.rs b/src/physical/columns/interval_column.rs
index a79129a2f..ed061ad9c 100644
--- a/src/physical/columns/interval_column.rs
+++ b/src/physical/columns/interval_column.rs
@@ -98,8 +98,6 @@ pub enum IntervalColumnT {
     Float(IntervalColumnEnum<Float>),
     /// Case Double
     Double(IntervalColumnEnum<Double>),
-    /// Case String
-    String(IntervalColumnEnum<usize>),
 }
 
 generate_datatype_forwarder!(forward_to_interval_column_enum);
diff --git a/src/physical/columns/ranged_column_scan.rs b/src/physical/columns/ranged_column_scan.rs
index 3c666f188..85109fe9e 100644
--- a/src/physical/columns/ranged_column_scan.rs
+++ b/src/physical/columns/ranged_column_scan.rs
@@ -354,8 +354,6 @@ pub enum RangedColumnScanT<'a> {
     Float(RangedColumnScanCell<'a, Float>),
     /// Case Double
     Double(RangedColumnScanCell<'a, Double>),
-    /// Case String
-    String(RangedColumnScanCell<'a, usize>),
 }
 
 generate_datatype_forwarder!(forward_to_ranged_column_scan_cell);
@@ -401,25 +399,15 @@ impl<'a> ColumnScan for RangedColumnScanT<'a> {
         match self {
             Self::U64(cs) => match value {
                 Self::Item::U64(val) => cs.seek(val).map(DataValueT::U64),
-                Self::Item::Float(_) => None,
-                Self::Item::Double(_) => None,
-                Self::Item::String(_) => None,
+                Self::Item::Float(_) | Self::Item::Double(_) => None,
             },
             Self::Float(cs) => match value {
-                Self::Item::U64(_) => None,
+                Self::Item::U64(_) | Self::Item::Double(_) => None,
                 Self::Item::Float(val) => cs.seek(val).map(DataValueT::Float),
-                Self::Item::Double(_) => None,
-                Self::Item::String(_) => None,
             },
             Self::Double(cs) => match value {
-                Self::Item::U64(_) => None,
-                Self::Item::Float(_) => None,
+                Self::Item::U64(_) | Self::Item::Float(_) => None,
                 Self::Item::Double(val) => cs.seek(val).map(DataValueT::Double),
-                Self::Item::String(_) => None,
-            },
-            Self::String(cs) => match value {
-                Self::Item::String(val) => cs.seek(val).map(DataValueT::String),
-                _ => None, // no type mixing allowed, so in any other case it should be [None]
             },
         }
     }
diff --git a/src/physical/datatypes/data_type_name.rs b/src/physical/datatypes/data_type_name.rs
index 3169ec15a..d1e45412c 100644
--- a/src/physical/datatypes/data_type_name.rs
+++ b/src/physical/datatypes/data_type_name.rs
@@ -1,7 +1,6 @@
 use crate::error::Error;
 
 use super::DataValueT;
-use crate::physical::dictionary::Dictionary;
 
 /// Descriptors to refer to the possible data types at runtime.
 #[derive(Clone, Copy, Debug, Ord, PartialOrd, Eq, PartialEq)]
@@ -12,18 +11,15 @@ pub enum DataTypeName {
     Float,
     /// Data type [`super::double::Double`]
     Double,
-    /// Data type `String`, uses [`usize`] and a [dictionary][crate::physical::dictionary::Dictionary]
-    String,
 }
 
 impl DataTypeName {
     /// Parses a string, based on the name of the Datatype
-    pub fn parse(&self, string: &str, dict: &mut dyn Dictionary) -> Result<DataValueT, Error> {
+    pub fn parse(&self, string: &str) -> Result<DataValueT, Error> {
         Ok(match self {
             DataTypeName::U64 => DataValueT::U64(string.parse::<u64>()?),
             DataTypeName::Float => DataValueT::Float(super::Float::new(string.parse::<f32>()?)?),
             DataTypeName::Double => DataValueT::Double(super::Double::new(string.parse::<f64>()?)?),
-            DataTypeName::String => DataValueT::String(dict.add(string.to_string())),
         })
     }
 }
diff --git a/src/physical/datatypes/data_value.rs b/src/physical/datatypes/data_value.rs
index 2696d30f6..842bd7957 100644
--- a/src/physical/datatypes/data_value.rs
+++ b/src/physical/datatypes/data_value.rs
@@ -18,8 +18,6 @@ pub enum DataValueT {
     Float(Float),
     /// Case Double
     Double(Double),
-    /// Case String
-    String(usize),
 }
 
 impl DataValueT {
@@ -47,21 +45,12 @@ impl DataValueT {
         }
     }
 
-    /// Returns an [`Option<usize>`] , answering whether the [`DataValueT`] is of this datatype
-    pub fn as_string(&self) -> Option<usize> {
-        match *self {
-            DataValueT::String(val) => Some(val),
-            _ => None,
-        }
-    }
-
     /// Compares its value with another given [`DataValueT`]
     pub fn compare(&self, other: &Self) -> Option<Ordering> {
         match self {
             DataValueT::U64(val) => other.as_u64().map(|otherval| val.cmp(&otherval)),
             DataValueT::Float(val) => other.as_float().map(|otherval| val.cmp(&otherval)),
             DataValueT::Double(val) => other.as_double().map(|otherval| val.cmp(&otherval)),
-            DataValueT::String(val) => other.as_string().map(|otherval| val.cmp(&otherval)),
         }
     }
 
@@ -71,7 +60,6 @@ impl DataValueT {
             Self::U64(_) => DataTypeName::U64,
             Self::Float(_) => DataTypeName::Float,
             Self::Double(_) => DataTypeName::Double,
-            Self::String(_) => DataTypeName::String,
         }
     }
 }
@@ -82,7 +70,6 @@ impl std::fmt::Display for DataValueT {
             Self::U64(val) => write!(f, "{}", val),
             Self::Float(val) => write!(f, "{}", val),
             Self::Double(val) => write!(f, "{}", val),
-            Self::String(val) => write!(f, "str{}", val),
         }
     }
 }
@@ -96,8 +83,6 @@ pub enum VecT {
     Float(Vec<Float>),
     /// Case Vec<Double>
     Double(Vec<Double>),
-    /// Case Vec<String>
-    String(Vec<usize>),
 }
 
 generate_datatype_forwarder!(forward_to_vec);
@@ -109,7 +94,6 @@ impl VecT {
             DataTypeName::U64 => Self::U64(Vec::new()),
             DataTypeName::Float => Self::Float(Vec::new()),
             DataTypeName::Double => Self::Double(Vec::new()),
-            DataTypeName::String => Self::String(Vec::new()),
         }
     }
 
@@ -119,7 +103,6 @@ impl VecT {
             Self::U64(_) => DataTypeName::U64,
             Self::Float(_) => DataTypeName::Float,
             Self::Double(_) => DataTypeName::Double,
-            Self::String(_) => DataTypeName::String,
         }
     }
 
@@ -134,7 +117,6 @@ impl VecT {
             VecT::U64(vec) => vec.get(index).copied().map(DataValueT::U64),
             VecT::Float(vec) => vec.get(index).copied().map(DataValueT::Float),
             VecT::Double(vec) => vec.get(index).copied().map(DataValueT::Double),
-            VecT::String(vec) => vec.get(index).copied().map(DataValueT::String),
         }
     }
 
@@ -153,9 +135,6 @@ impl VecT {
             VecT::Double(vec) => vec.push(value.as_double().expect(
                 "expecting VecT::Double and DataValueT::Double, but DataValueT does not match",
             )),
-            VecT::String(vec) => vec.push(value.as_string().expect(
-                "expecting VecT::String and DataValueT::String, but DataValueT does not match",
-            )),
         };
     }
 
@@ -182,9 +161,6 @@ impl VecT {
             VecT::Double(vec) => vec
                 .get(idx_a)
                 .and_then(|&val_a| vec.get(idx_b).map(|val_b| val_a.cmp(val_b))),
-            VecT::String(vec) => vec
-                .get(idx_a)
-                .and_then(|&val_a| vec.get(idx_b).map(|val_b| val_a.cmp(val_b))),
         }
     }
 }
diff --git a/src/physical/tables/materialize.rs b/src/physical/tables/materialize.rs
index e894453f8..f9642d57e 100644
--- a/src/physical/tables/materialize.rs
+++ b/src/physical/tables/materialize.rs
@@ -34,8 +34,6 @@ pub fn materialize(trie_scan: &mut TrieScanEnum) -> Trie {
                 .push(AdaptiveColumnBuilderT::Float(AdaptiveColumnBuilder::new())),
             DataTypeName::Double => data_column_builders
                 .push(AdaptiveColumnBuilderT::Double(AdaptiveColumnBuilder::new())),
-            DataTypeName::String => data_column_builders
-                .push(AdaptiveColumnBuilderT::String(AdaptiveColumnBuilder::new())),
         }
     }
 
diff --git a/src/physical/tables/trie.rs b/src/physical/tables/trie.rs
index e55fadff6..2cc4a1834 100644
--- a/src/physical/tables/trie.rs
+++ b/src/physical/tables/trie.rs
@@ -181,7 +181,7 @@ impl Table for Trie {
                     .map(|_| {
                         let empty_data_col = AdaptiveColumnBuilderT::new(DataTypeName::U64);
                         let empty_interval_col = AdaptiveColumnBuilder::<usize>::new();
-                        build_interval_column!(empty_data_col, empty_interval_col; U64; Float; Double; String)
+                        build_interval_column!(empty_data_col, empty_interval_col; U64; Float; Double)
                     })
                     .collect(),
             );
@@ -201,9 +201,6 @@ impl Table for Trie {
                     VecT::Double(vec) => VecT::Double(permutator.permutate(vec).expect(
                         "length matches since permutator is constructed from these vectores",
                     )),
-                    VecT::String(vec) => VecT::String(permutator.permutate(vec).expect(
-                        "length matches since permutator is constructed from these vectors",
-                    )),
                 })
                 .collect();
 
@@ -294,7 +291,7 @@ impl Table for Trie {
             condensed_data_builders
                 .into_iter()
                 .zip(condensed_interval_starts_builders)
-                .map(|(col, iv)| build_interval_column!(col, iv; U64; Float; Double; String))
+                .map(|(col, iv)| build_interval_column!(col, iv; U64; Float; Double))
                 .collect(),
         )
     }
diff --git a/src/physical/tables/trie_difference.rs b/src/physical/tables/trie_difference.rs
index 6457fa071..ca99c5346 100644
--- a/src/physical/tables/trie_difference.rs
+++ b/src/physical/tables/trie_difference.rs
@@ -67,7 +67,6 @@ impl<'a> TrieDifference<'a> {
                 DataTypeName::U64 => init_scans_for_datatype!(U64),
                 DataTypeName::Float => init_scans_for_datatype!(Float),
                 DataTypeName::Double => init_scans_for_datatype!(Double),
-                DataTypeName::String => init_scans_for_datatype!(String),
             };
         }
 
@@ -158,7 +157,6 @@ impl<'a> TrieScan<'a> for TrieDifference<'a> {
                 DataTypeName::U64 => down_for_datatype!(U64),
                 DataTypeName::Float => down_for_datatype!(Float),
                 DataTypeName::Double => down_for_datatype!(Double),
-                DataTypeName::String => down_for_datatype!(String),
             }
         } else {
             self.difference_scans[next_layer].get_mut().reset();
diff --git a/src/physical/tables/trie_join.rs b/src/physical/tables/trie_join.rs
index 2e4167716..e277c0f0d 100644
--- a/src/physical/tables/trie_join.rs
+++ b/src/physical/tables/trie_join.rs
@@ -88,7 +88,6 @@ impl<'a> TrieJoin<'a> {
                 DataTypeName::U64 => merge_join_for_datatype!(U64, u64),
                 DataTypeName::Float => merge_join_for_datatype!(Float, Float),
                 DataTypeName::Double => merge_join_for_datatype!(Double, Double),
-                DataTypeName::String => merge_join_for_datatype!(String, usize),
             }
         }
 
@@ -138,10 +137,9 @@ impl<'a> TrieScan<'a> for TrieJoin<'a> {
         debug_assert!(self.current_variable.is_some());
 
         match self.target_schema.get_type(self.current_variable?) {
-            DataTypeName::U64
-            | DataTypeName::Float
-            | DataTypeName::Double
-            | DataTypeName::String => Some(&self.merge_joins[self.current_variable?]),
+            DataTypeName::U64 | DataTypeName::Float | DataTypeName::Double => {
+                Some(&self.merge_joins[self.current_variable?])
+            }
         }
     }
 
diff --git a/src/physical/tables/trie_project.rs b/src/physical/tables/trie_project.rs
index 4c4947449..6507721d6 100644
--- a/src/physical/tables/trie_project.rs
+++ b/src/physical/tables/trie_project.rs
@@ -35,7 +35,6 @@ fn shrink_position(column: &IntervalColumnT, pos: usize) -> usize {
         IntervalColumnT::U64(col) => shrink_position_t(col, pos),
         IntervalColumnT::Float(col) => shrink_position_t(col, pos),
         IntervalColumnT::Double(col) => shrink_position_t(col, pos),
-        IntervalColumnT::String(col) => shrink_position_t(col, pos),
     }
 }
 
@@ -88,7 +87,6 @@ impl<'a> TrieProject<'a> {
                 DataTypeName::U64 => init_scans_for_datatype!(U64),
                 DataTypeName::Float => init_scans_for_datatype!(Float),
                 DataTypeName::Double => init_scans_for_datatype!(Double),
-                DataTypeName::String => init_scans_for_datatype!(String),
             }
         }
         let target_schema = TrieSchema::new(target_attributes);
@@ -190,7 +188,6 @@ impl<'a> TrieScan<'a> for TrieProject<'a> {
             IntervalColumnT::U64(_) => down_for_datatype!(U64),
             IntervalColumnT::Float(_) => down_for_datatype!(Float),
             IntervalColumnT::Double(_) => down_for_datatype!(Double),
-            IntervalColumnT::String(_) => down_for_datatype!(String),
         }
 
         self.current_layer = Some(next_layer);
diff --git a/src/physical/tables/trie_select.rs b/src/physical/tables/trie_select.rs
index 062ee7e6a..97f0123aa 100644
--- a/src/physical/tables/trie_select.rs
+++ b/src/physical/tables/trie_select.rs
@@ -46,7 +46,6 @@ impl<'a> TrieSelectEqual<'a> {
                 DataTypeName::U64 => init_scans_for_datatype!(U64),
                 DataTypeName::Float => init_scans_for_datatype!(Float),
                 DataTypeName::Double => init_scans_for_datatype!(Double),
-                DataTypeName::String => init_scans_for_datatype!(String),
             };
         }
 
@@ -88,7 +87,6 @@ impl<'a> TrieSelectEqual<'a> {
                     DataTypeName::U64 => init_scans_for_datatype!(U64),
                     DataTypeName::Float => init_scans_for_datatype!(Float),
                     DataTypeName::Double => init_scans_for_datatype!(Double),
-                    DataTypeName::String => init_scans_for_datatype!(String),
                 }
             }
         }
@@ -184,7 +182,6 @@ impl<'a> TrieSelectValue<'a> {
                 DataTypeName::U64 => init_scans_for_datatype!(U64),
                 DataTypeName::Float => init_scans_for_datatype!(Float),
                 DataTypeName::Double => init_scans_for_datatype!(Double),
-                DataTypeName::String => init_scans_for_datatype!(String),
             }
         }
 
@@ -220,7 +217,6 @@ impl<'a> TrieSelectValue<'a> {
                 DataTypeName::U64 => init_scans_for_datatype!(U64),
                 DataTypeName::Float => init_scans_for_datatype!(Float),
                 DataTypeName::Double => init_scans_for_datatype!(Double),
-                DataTypeName::String => init_scans_for_datatype!(String),
             }
         }
 
diff --git a/src/physical/tables/trie_union.rs b/src/physical/tables/trie_union.rs
index afc56df26..161ec551e 100644
--- a/src/physical/tables/trie_union.rs
+++ b/src/physical/tables/trie_union.rs
@@ -58,7 +58,6 @@ impl<'a> TrieUnion<'a> {
                 DataTypeName::U64 => init_scans_for_datatype!(U64, u64),
                 DataTypeName::Float => init_scans_for_datatype!(Float, Float),
                 DataTypeName::Double => init_scans_for_datatype!(Double, Double),
-                DataTypeName::String => init_scans_for_datatype!(String, usize),
             };
         }
 
diff --git a/src/physical/util.rs b/src/physical/util.rs
index 7ce3c2143..3b2d1a586 100644
--- a/src/physical/util.rs
+++ b/src/physical/util.rs
@@ -92,7 +92,6 @@ macro_rules! generate_datatype_forwarder {
         $crate::generate_forwarder!($name;
                                     U64,
                                     Float,
-                                    Double,
-				    String);
+                                    Double);
     }
 }