diff --git a/Cargo.lock b/Cargo.lock
index ff6ee7d53c..1df1788067 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -4075,6 +4075,7 @@ dependencies = [
 name = "spacetimedb-bindings-macro"
 version = "0.6.1"
 dependencies = [
+ "bitflags 2.3.3",
  "humantime",
  "proc-macro2",
  "quote",
@@ -4242,6 +4243,7 @@ name = "spacetimedb-lib"
 version = "0.6.1"
 dependencies = [
  "anyhow",
+ "bitflags 2.3.3",
  "bytes",
  "chrono",
  "clap 4.3.10",
diff --git a/Cargo.toml b/Cargo.toml
index 45270e5a94..bffd2cbea8 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -59,6 +59,7 @@ axum = "0.6"
 arrayvec = "0.7.2"
 backtrace = "0.3.66"
 base64 = "0.21.2"
+bitflags = "2.3.3"
 byte-unit = "4.0.18"
 bytes = "1.2.1"
 bytestring = { version = "1.2.0", features = ["serde"] }
diff --git a/crates/bindings-macro/Cargo.toml b/crates/bindings-macro/Cargo.toml
index 9be1b9662a..e69003c8b5 100644
--- a/crates/bindings-macro/Cargo.toml
+++ b/crates/bindings-macro/Cargo.toml
@@ -11,6 +11,7 @@ proc-macro = true
 bench = false
 
 [dependencies]
+bitflags.workspace = true
 humantime.workspace = true
 proc-macro2.workspace = true
 quote.workspace = true
diff --git a/crates/bindings-macro/src/lib.rs b/crates/bindings-macro/src/lib.rs
index 265e5a6508..de357fd8b9 100644
--- a/crates/bindings-macro/src/lib.rs
+++ b/crates/bindings-macro/src/lib.rs
@@ -14,6 +14,7 @@ extern crate proc_macro;
 use std::collections::HashMap;
 use std::time::Duration;
 
+use bitflags::{bitflags, Flags};
 use module::{derive_deserialize, derive_satstype, derive_serialize};
 use proc_macro2::{Span, TokenStream};
 use quote::{format_ident, quote, quote_spanned, TokenStreamExt};
@@ -442,22 +443,24 @@ struct Column<'a> {
     attr: ColumnIndexAttribute,
 }
 
-#[derive(Debug)]
-enum ColumnIndexAttribute {
-    UnSet = 0,
-    /// Unique + AutoInc
-    Identity = 1,
-    /// Index unique
-    Unique = 2,
-    ///  Index no unique
-    #[allow(unused)]
-    Indexed = 3,
-    /// Generate the next [Sequence]
-    AutoInc = 4,
-    /// Primary key column (implies Unique)
-    PrimaryKey = 5,
-    /// PrimaryKey + AutoInc
-    PrimaryKeyAuto = 6,
+// TODO: any way to avoid duplication with same structure in bindings crate? Extra crate?
+bitflags! {
+    #[derive(Debug, Default, Clone, Copy, Eq, PartialEq, PartialOrd, Ord)]
+    struct ColumnIndexAttribute: u8 {
+        const UNSET = Self::empty().bits();
+        ///  Index no unique
+        const INDEXED = 0b0001;
+        /// Generate the next [Sequence]
+        const AUTO_INC = 0b0010;
+        /// Index unique
+        const UNIQUE = Self::INDEXED.bits() | 0b0100;
+        /// Unique + AutoInc
+        const IDENTITY = Self::UNIQUE.bits() | Self::AUTO_INC.bits();
+        /// Primary key column (implies Unique)
+        const PRIMARY_KEY = Self::UNIQUE.bits() | 0b1000;
+        /// PrimaryKey + AutoInc
+        const PRIMARY_KEY_AUTO = Self::PRIMARY_KEY.bits() | Self::AUTO_INC.bits();
+    }
 }
 
 fn spacetimedb_table(item: TokenStream) -> syn::Result<TokenStream> {
@@ -551,35 +554,27 @@ fn spacetimedb_tabletype_impl(item: syn::DeriveInput) -> syn::Result<TokenStream
             .try_into()
             .map_err(|_| syn::Error::new_spanned(field.ident, "too many columns; the most a table can have is 256"))?;
 
-        use ColumnIndexAttribute::*;
-        let mut col_attr = UnSet;
+        let mut col_attr = ColumnIndexAttribute::UNSET;
         for attr in field.original_attrs {
             let Some(attr) = ColumnAttr::parse(attr)? else { continue };
             let duplicate = |span| syn::Error::new(span, "duplicate attribute");
-            match attr {
-                ColumnAttr::Unique(span) => match col_attr {
-                    UnSet => col_attr = Unique,
-                    Identity | Unique | PrimaryKey | PrimaryKeyAuto => return Err(duplicate(span)),
-                    Indexed => unreachable!(),
-                    AutoInc => col_attr = Identity,
-                },
-                ColumnAttr::Autoinc(span) => match col_attr {
-                    UnSet => col_attr = AutoInc,
-                    Identity | AutoInc | PrimaryKeyAuto => return Err(duplicate(span)),
-                    Unique => col_attr = Identity,
-                    Indexed => unreachable!(),
-                    PrimaryKey => col_attr = PrimaryKeyAuto,
-                },
-                ColumnAttr::Primarykey(span) => match col_attr {
-                    UnSet => col_attr = PrimaryKey,
-                    Identity | Unique | PrimaryKey | PrimaryKeyAuto => return Err(duplicate(span)),
-                    AutoInc => col_attr = PrimaryKeyAuto,
-                    Indexed => unreachable!(),
-                },
+            let (extra_col_attr, span) = match attr {
+                ColumnAttr::Unique(span) => (ColumnIndexAttribute::UNIQUE, span),
+                ColumnAttr::Autoinc(span) => (ColumnIndexAttribute::AUTO_INC, span),
+                ColumnAttr::Primarykey(span) => (ColumnIndexAttribute::PRIMARY_KEY, span),
+            };
+            // do those attributes intersect (not counting the INDEXED bit which is present in all attributes)?
+            // this will check that no two attributes both have UNIQUE, AUTOINC or PRIMARY_KEY bits set
+            if !(col_attr & extra_col_attr)
+                .difference(ColumnIndexAttribute::INDEXED)
+                .is_empty()
+            {
+                return Err(duplicate(span));
             }
+            col_attr |= extra_col_attr;
         }
 
-        if matches!(col_attr, AutoInc | Identity | PrimaryKeyAuto) {
+        if col_attr.contains(ColumnIndexAttribute::AUTO_INC) {
             let valid_for_autoinc = if let syn::Type::Path(p) = field.ty {
                 // TODO: this is janky as heck
                 matches!(
@@ -631,15 +626,9 @@ fn spacetimedb_tabletype_impl(item: syn::DeriveInput) -> syn::Result<TokenStream
         }));
     }
 
-    let (unique_columns, nonunique_columns): (Vec<_>, Vec<_>) = columns.iter().partition(|x| {
-        matches!(
-            x.attr,
-            ColumnIndexAttribute::Identity
-                | ColumnIndexAttribute::Unique
-                | ColumnIndexAttribute::PrimaryKey
-                | ColumnIndexAttribute::PrimaryKeyAuto
-        )
-    });
+    let (unique_columns, nonunique_columns): (Vec<_>, Vec<_>) = columns
+        .iter()
+        .partition(|x| x.attr.contains(ColumnIndexAttribute::UNIQUE));
 
     let has_unique = !unique_columns.is_empty();
 
@@ -746,9 +735,15 @@ fn spacetimedb_tabletype_impl(item: syn::DeriveInput) -> syn::Result<TokenStream
     let deserialize_impl = derive_deserialize(&sats_ty);
     let serialize_impl = derive_serialize(&sats_ty);
     let schema_impl = derive_satstype(&sats_ty, false);
-    let column_attrs = columns
-        .iter()
-        .map(|col| Ident::new(&format!("{:?}", col.attr), Span::call_site()));
+    let column_attrs = columns.iter().map(|col| {
+        Ident::new(
+            ColumnIndexAttribute::FLAGS
+                .iter()
+                .find_map(|f| (col.attr == *f.value()).then_some(f.name()))
+                .expect("Invalid column attribute"),
+            Span::call_site(),
+        )
+    });
     let tabletype_impl = quote! {
         impl spacetimedb::TableType for #original_struct_ident {
             const TABLE_NAME: &'static str = #table_name;
diff --git a/crates/bindings-sys/src/lib.rs b/crates/bindings-sys/src/lib.rs
index 5de0a8177b..f93c352868 100644
--- a/crates/bindings-sys/src/lib.rs
+++ b/crates/bindings-sys/src/lib.rs
@@ -34,7 +34,7 @@ use alloc::boxed::Box;
 /// can run a module declaring `X.Y` if and only if `X == A && Y <= B`.
 /// So, the minor version is intended for backwards-compatible changes, e.g. adding a new function,
 /// and the major version is for fully breaking changes.
-pub const ABI_VERSION: u32 = 0x0003_0000;
+pub const ABI_VERSION: u32 = 0x0004_0000;
 
 /// Provides a raw set of sys calls which abstractions can be built atop of.
 pub mod raw {
diff --git a/crates/core/src/db/datastore/traits.rs b/crates/core/src/db/datastore/traits.rs
index c5e97bdadd..21ca543aca 100644
--- a/crates/core/src/db/datastore/traits.rs
+++ b/crates/core/src/db/datastore/traits.rs
@@ -113,9 +113,9 @@ impl From<&ColumnSchema> for spacetimedb_lib::table::ColumnDef {
             // TODO(cloutiertyler): !!! This is not correct !!! We do not have the information regarding constraints here.
             // We should remove this field from the ColumnDef struct.
             attr: if value.is_autoinc {
-                spacetimedb_lib::ColumnIndexAttribute::AutoInc
+                spacetimedb_lib::ColumnIndexAttribute::AUTO_INC
             } else {
-                spacetimedb_lib::ColumnIndexAttribute::UnSet
+                spacetimedb_lib::ColumnIndexAttribute::UNSET
             },
             // if value.is_autoinc && value.is_unique {
             //     spacetimedb_lib::ColumnIndexAttribute::Identity
diff --git a/crates/core/src/db/relational_db.rs b/crates/core/src/db/relational_db.rs
index 80db98e74a..31c68020ae 100644
--- a/crates/core/src/db/relational_db.rs
+++ b/crates/core/src/db/relational_db.rs
@@ -334,13 +334,18 @@ impl RelationalDB {
             return Ok(None);
         };
         let unique_index = table.indexes.iter().find(|x| x.col_id == col_id).map(|x| x.is_unique);
-        Ok(Some(match (column.is_autoinc, unique_index) {
-            (true, Some(true)) => ColumnIndexAttribute::Identity,
-            (true, Some(false) | None) => ColumnIndexAttribute::AutoInc,
-            (false, Some(true)) => ColumnIndexAttribute::Unique,
-            (false, Some(false)) => ColumnIndexAttribute::Indexed,
-            (false, None) => ColumnIndexAttribute::UnSet,
-        }))
+        let mut attr = ColumnIndexAttribute::UNSET;
+        if column.is_autoinc {
+            attr |= ColumnIndexAttribute::AUTO_INC;
+        }
+        if let Some(is_unique) = unique_index {
+            attr |= if is_unique {
+                ColumnIndexAttribute::UNIQUE
+            } else {
+                ColumnIndexAttribute::INDEXED
+            };
+        }
+        Ok(Some(attr))
     }
 
     #[tracing::instrument(skip_all)]
diff --git a/crates/core/src/host/wasmer/wasmer_module.rs b/crates/core/src/host/wasmer/wasmer_module.rs
index 6309c2a135..716f4faed6 100644
--- a/crates/core/src/host/wasmer/wasmer_module.rs
+++ b/crates/core/src/host/wasmer/wasmer_module.rs
@@ -45,7 +45,7 @@ impl WasmerModule {
         WasmerModule { module, engine }
     }
 
-    pub const IMPLEMENTED_ABI: abi::VersionTuple = abi::VersionTuple::new(3, 0);
+    pub const IMPLEMENTED_ABI: abi::VersionTuple = abi::VersionTuple::new(4, 0);
 
     fn imports(&self, store: &mut Store, env: &FunctionEnv<WasmInstanceEnv>) -> Imports {
         const _: () = assert!(WasmerModule::IMPLEMENTED_ABI.eq(spacetimedb_lib::MODULE_ABI_VERSION));
diff --git a/crates/core/src/sql/ast.rs b/crates/core/src/sql/ast.rs
index 9169437c09..351dbb2cf5 100644
--- a/crates/core/src/sql/ast.rs
+++ b/crates/core/src/sql/ast.rs
@@ -766,7 +766,7 @@ fn column_def_type(named: &String, is_null: bool, data_type: &DataType) -> Resul
 
 /// Extract the column attributes into [ColumnIndexAttribute]
 fn compile_column_option(col: &SqlColumnDef) -> Result<(bool, ColumnIndexAttribute), PlanError> {
-    let mut attr = ColumnIndexAttribute::UnSet;
+    let mut attr = ColumnIndexAttribute::UNSET;
     let mut is_null = false;
 
     for x in &col.options {
@@ -778,11 +778,11 @@ fn compile_column_option(col: &SqlColumnDef) -> Result<(bool, ColumnIndexAttribu
                 is_null = false;
             }
             ColumnOption::Unique { is_primary } => {
-                if *is_primary {
-                    attr = ColumnIndexAttribute::PrimaryKey
+                attr = if *is_primary {
+                    ColumnIndexAttribute::PRIMARY_KEY
                 } else {
-                    attr = ColumnIndexAttribute::Unique
-                }
+                    ColumnIndexAttribute::UNIQUE
+                };
             }
             ColumnOption::Generated {
                 generated_as,
@@ -793,11 +793,7 @@ fn compile_column_option(col: &SqlColumnDef) -> Result<(bool, ColumnIndexAttribu
 
                 match generated_as {
                     GeneratedAs::ByDefault => {
-                        if attr == ColumnIndexAttribute::PrimaryKey {
-                            attr = ColumnIndexAttribute::PrimaryKeyAuto
-                        } else {
-                            attr = ColumnIndexAttribute::Identity
-                        }
+                        attr |= ColumnIndexAttribute::IDENTITY;
                     }
                     x => {
                         return Err(PlanError::Unsupported {
diff --git a/crates/lib/Cargo.toml b/crates/lib/Cargo.toml
index 6bb97b5bc1..fb3749c232 100644
--- a/crates/lib/Cargo.toml
+++ b/crates/lib/Cargo.toml
@@ -23,6 +23,7 @@ spacetimedb-bindings-macro = { path = "../bindings-macro", version = "0.6.1" }
 spacetimedb-sats = { path = "../sats", version = "0.6.1" }
 
 anyhow.workspace = true
+bitflags.workspace = true
 chrono = { workspace = true, optional = true }
 clap = {workspace = true, optional = true }
 enum-as-inner.workspace = true
diff --git a/crates/lib/src/lib.rs b/crates/lib/src/lib.rs
index f4e5df2ec0..d9c7e4eaee 100644
--- a/crates/lib/src/lib.rs
+++ b/crates/lib/src/lib.rs
@@ -41,7 +41,7 @@ pub use type_value::{AlgebraicValue, ProductValue};
 
 pub use spacetimedb_sats as sats;
 
-pub const MODULE_ABI_VERSION: VersionTuple = VersionTuple::new(3, 0);
+pub const MODULE_ABI_VERSION: VersionTuple = VersionTuple::new(4, 0);
 
 // if it ends up we need more fields in the future, we can split one of them in two
 #[derive(PartialEq, Eq, Copy, Clone, Debug)]
@@ -205,36 +205,34 @@ pub enum IndexType {
     Hash,
 }
 
-#[derive(Debug, Default, Clone, Copy, Eq, PartialEq, PartialOrd, Ord, de::Deserialize, ser::Serialize)]
-pub enum ColumnIndexAttribute {
-    #[default]
-    UnSet = 0,
-    /// Unique + AutoInc
-    Identity = 1,
-    /// Index unique
-    Unique = 2,
-    ///  Index no unique
-    Indexed = 3,
-    /// Generate the next [Sequence]
-    AutoInc = 4,
-    /// Primary key column (implies Unique)
-    PrimaryKey = 5,
-    /// PrimaryKey + AutoInc
-    PrimaryKeyAuto = 6,
+bitflags::bitflags! {
+    #[derive(Debug, Default, Clone, Copy, Eq, PartialEq, PartialOrd, Ord)]
+    pub struct ColumnIndexAttribute: u8 {
+        const UNSET = Self::empty().bits();
+        ///  Index no unique
+        const INDEXED = 0b0001;
+        /// Generate the next [Sequence]
+        const AUTO_INC = 0b0010;
+        /// Index unique
+        const UNIQUE = Self::INDEXED.bits() | 0b0100;
+        /// Unique + AutoInc
+        const IDENTITY = Self::UNIQUE.bits() | Self::AUTO_INC.bits();
+        /// Primary key column (implies Unique)
+        const PRIMARY_KEY = Self::UNIQUE.bits() | 0b1000;
+        /// PrimaryKey + AutoInc
+        const PRIMARY_KEY_AUTO = Self::PRIMARY_KEY.bits() | Self::AUTO_INC.bits();
+    }
 }
 
 impl ColumnIndexAttribute {
     pub const fn is_unique(self) -> bool {
-        matches!(
-            self,
-            Self::Identity | Self::Unique | Self::PrimaryKey | Self::PrimaryKeyAuto
-        )
+        self.contains(Self::UNIQUE)
     }
     pub const fn is_autoinc(self) -> bool {
-        matches!(self, Self::Identity | Self::AutoInc | Self::PrimaryKeyAuto)
+        self.contains(Self::AUTO_INC)
     }
     pub const fn is_primary(self) -> bool {
-        matches!(self, Self::PrimaryKey | Self::PrimaryKeyAuto)
+        self.contains(Self::PRIMARY_KEY)
     }
 }
 
@@ -242,15 +240,19 @@ impl TryFrom<u8> for ColumnIndexAttribute {
     type Error = ();
 
     fn try_from(v: u8) -> Result<Self, Self::Error> {
-        match v {
-            0 => Ok(Self::UnSet),
-            1 => Ok(Self::Identity),
-            2 => Ok(Self::Unique),
-            3 => Ok(Self::Indexed),
-            4 => Ok(Self::AutoInc),
-            5 => Ok(Self::PrimaryKey),
-            6 => Ok(Self::PrimaryKeyAuto),
-            _ => Err(()),
-        }
+        Self::from_bits(v).ok_or(())
+    }
+}
+
+impl<'de> de::Deserialize<'de> for ColumnIndexAttribute {
+    fn deserialize<D: de::Deserializer<'de>>(deserializer: D) -> Result<Self, D::Error> {
+        Self::from_bits(deserializer.deserialize_u8()?)
+            .ok_or_else(|| de::Error::custom("invalid bitflags for ColumnIndexAttribute"))
+    }
+}
+
+impl ser::Serialize for ColumnIndexAttribute {
+    fn serialize<S: ser::Serializer>(&self, serializer: S) -> Result<S::Ok, S::Error> {
+        serializer.serialize_u8(self.bits())
     }
 }
diff --git a/crates/lib/src/table.rs b/crates/lib/src/table.rs
index 887c87c6d6..49765f49c6 100644
--- a/crates/lib/src/table.rs
+++ b/crates/lib/src/table.rs
@@ -20,7 +20,7 @@ pub struct ProductTypeMeta {
 impl ProductTypeMeta {
     pub fn new(columns: ProductType) -> Self {
         Self {
-            attr: vec![ColumnIndexAttribute::UnSet; columns.elements.len()],
+            attr: vec![ColumnIndexAttribute::UNSET; columns.elements.len()],
             columns,
         }
     }
@@ -100,12 +100,9 @@ impl ProductTypeMeta {
         &'a self,
         row: &'a mut ProductValue,
     ) -> impl Iterator<Item = (ColumnDef, &'a mut AlgebraicValue)> + 'a {
-        self.iter().zip(row.elements.iter_mut()).filter(|(col, _)| {
-            matches!(
-                col.attr,
-                ColumnIndexAttribute::Identity | ColumnIndexAttribute::AutoInc | ColumnIndexAttribute::PrimaryKeyAuto
-            )
-        })
+        self.iter()
+            .zip(row.elements.iter_mut())
+            .filter(|(col, _)| col.attr.is_autoinc())
     }
 }