Refactor building schema statements

.github/actions/android/action.yml

@@ -25,8 +25,8 @@ runs:
     - name: Setup
       shell: bash
       run: |
-        rustup toolchain install nightly-2025-10-31-x86_64-unknown-linux-gnu
-        rustup component add rust-src --toolchain nightly-2025-10-31-x86_64-unknown-linux-gnu
+        rustup toolchain install nightly-2025-12-05-x86_64-unknown-linux-gnu
+        rustup component add rust-src --toolchain nightly-2025-12-05-x86_64-unknown-linux-gnu
         rustup target add \
           aarch64-linux-android \
           armv7-linux-androideabi \

.github/actions/linux/action.yml

@@ -7,7 +7,7 @@ runs:
     - name: Install Rust Nightly
       uses: dtolnay/rust-toolchain@stable
       with:
-        toolchain: nightly-2025-10-31
+        toolchain: nightly-2025-12-05
         components: rust-src
         targets: aarch64-unknown-linux-gnu,x86_64-unknown-linux-gnu,i686-unknown-linux-gnu,riscv64gc-unknown-linux-gnu,armv7-unknown-linux-gnueabihf
 

.github/actions/macos/action.yml

@@ -7,7 +7,7 @@ runs:
     - name: Install Rust Nightly
       uses: dtolnay/rust-toolchain@stable
       with:
-        toolchain: nightly-2025-10-31
+        toolchain: nightly-2025-12-05
         components: rust-src
         targets: x86_64-apple-darwin,aarch64-apple-darwin
 

.github/actions/wasm/action.yml

@@ -7,7 +7,7 @@ runs:
     - name: Install Rust Nightly
       uses: dtolnay/rust-toolchain@stable
       with:
-        toolchain: nightly-2025-10-31
+        toolchain: nightly-2025-12-05
         components: rust-src
 
     - name: Setup emsdk

.github/actions/windows/action.yml

@@ -7,7 +7,7 @@ runs:
     - name: Install Rust Nightly
       uses: dtolnay/rust-toolchain@stable
       with:
-        toolchain: nightly-2025-10-31
+        toolchain: nightly-2025-12-05
         components: rust-src
         targets: x86_64-pc-windows-msvc,aarch64-pc-windows-msvc,i686-pc-windows-msvc
 

.github/actions/xcframework/action.yml

@@ -7,8 +7,8 @@ runs:
     - name: Setup
       shell: bash
       run: |
-        rustup toolchain install nightly-2025-10-31-aarch64-apple-darwin
-        rustup component add rust-src --toolchain nightly-2025-10-31-aarch64-apple-darwin
+        rustup toolchain install nightly-2025-12-05-aarch64-apple-darwin
+        rustup component add rust-src --toolchain nightly-2025-12-05-aarch64-apple-darwin
         rustup target add \
           x86_64-apple-darwin \
           aarch64-apple-darwin \

.github/workflows/tests.yml

@@ -81,7 +81,7 @@ jobs:
       - name: Install Rust Nightly
         uses: dtolnay/rust-toolchain@stable
         with:
-          toolchain: nightly-2025-10-31
+          toolchain: nightly-2025-12-05
           components: rust-src,rustfmt,clippy
 
       - name: Check formatting
@@ -201,15 +201,17 @@ jobs:
       - name: Install Rust Nightly
         uses: dtolnay/rust-toolchain@stable
         with:
-          toolchain: nightly-2025-10-31
+          toolchain: nightly-2025-12-05
           components: rust-src
 
       - name: Install valgrind
         run: sudo apt update && sudo apt install -y valgrind
 
       - name: Install Cargo Valgrind
-        run: |
-          cargo install cargo-valgrind
+        # TODO: Use released version. Currently we rely on the git version while we wait for this
+        # to be released: https://github.com/jfrimmel/cargo-valgrind/commit/408c0b4fb56e84eddc2bb09c88a11ba3adc0c188
+        run: cargo install --git https://github.com/jfrimmel/cargo-valgrind cargo-valgrind
+        #run: cargo install cargo-valgrind
 
       - name: Test Core
         run: |

crates/core/src/crud_vtab.rs

@@ -15,7 +15,7 @@ use crate::error::PowerSyncError;
 use crate::ext::SafeManagedStmt;
 use crate::schema::TableInfoFlags;
 use crate::state::DatabaseState;
-use crate::util::MAX_OP_ID;
+use crate::utils::MAX_OP_ID;
 use crate::vtab_util::*;
 
 const MANUAL_NAME: &CStr = c"powersync_crud_";

crates/core/src/fix_data.rs

@@ -6,11 +6,11 @@ use alloc::string::String;
 use crate::create_sqlite_optional_text_fn;
 use crate::error::{PSResult, PowerSyncError};
 use crate::schema::inspection::ExistingTable;
+use crate::utils::SqlBuffer;
 use powersync_sqlite_nostd::{self as sqlite, ColumnType, Value};
 use powersync_sqlite_nostd::{Connection, Context, ResultCode};
 
 use crate::ext::SafeManagedStmt;
-use crate::util::quote_identifier;
 
 // Apply a data migration to fix any existing data affected by the issue
 // fixed in v0.3.5.
@@ -33,7 +33,7 @@ pub fn apply_v035_fix(db: *mut sqlite::sqlite3) -> Result<i64, PowerSyncError> {
             continue;
         };
 
-        let quoted = quote_identifier(full_name);
+        let quoted = SqlBuffer::quote_identifier(full_name);
 
         // language=SQLite
         let statement = db.prepare_v2(&format!(

crates/core/src/lib.rs

@@ -28,7 +28,7 @@ mod state;
 mod sync;
 mod sync_local;
 mod update_hooks;
-mod util;
+mod utils;
 mod uuid;
 mod version;
 mod view_admin;

crates/core/src/schema/inspection.rs

@@ -5,7 +5,7 @@ use powersync_sqlite_nostd::Connection;
 use powersync_sqlite_nostd::{self as sqlite, ResultCode};
 
 use crate::error::{PSResult, PowerSyncError};
-use crate::util::quote_identifier;
+use crate::utils::SqlBuffer;
 
 /// An existing PowerSync-managed view that was found in the schema.
 #[derive(PartialEq)]
@@ -64,7 +64,7 @@ SELECT
     }
 
     pub fn drop_by_name(db: *mut sqlite::sqlite3, name: &str) -> Result<(), PowerSyncError> {
-        let q = format!("DROP VIEW IF EXISTS {:}", quote_identifier(name));
+        let q = format!("DROP VIEW IF EXISTS {:}", SqlBuffer::quote_identifier(name));
         db.exec_safe(&q)?;
         Ok(())
     }

crates/core/src/schema/management.rs

@@ -7,6 +7,7 @@ use alloc::string::String;
 use alloc::vec::Vec;
 use alloc::{format, vec};
 use core::ffi::c_int;
+use core::fmt::Write;
 
 use powersync_sqlite_nostd as sqlite;
 use powersync_sqlite_nostd::Context;
@@ -15,8 +16,9 @@ use sqlite::{Connection, ResultCode, Value};
 use crate::error::{PSResult, PowerSyncError};
 use crate::ext::ExtendedDatabase;
 use crate::schema::inspection::{ExistingTable, ExistingView};
+use crate::schema::table_info::Index;
 use crate::state::DatabaseState;
-use crate::util::{quote_identifier, quote_json_path};
+use crate::utils::SqlBuffer;
 use crate::views::{
     powersync_trigger_delete_sql, powersync_trigger_insert_sql, powersync_trigger_update_sql,
     powersync_view_sql,
@@ -54,7 +56,7 @@ fn update_tables(db: *mut sqlite::sqlite3, schema: &Schema) -> Result<(), PowerS
             }
 
             // New table.
-            let quoted_internal_name = quote_identifier(&table.internal_name());
+            let quoted_internal_name = SqlBuffer::quote_identifier(&table.internal_name());
 
             db.exec_safe(&format!(
                 "CREATE TABLE {:}(id TEXT PRIMARY KEY NOT NULL, data TEXT)",
@@ -88,7 +90,7 @@ fn update_tables(db: *mut sqlite::sqlite3, schema: &Schema) -> Result<(), PowerS
                 db.exec_text(
                     &format!(
                         "INSERT INTO ps_untyped(type, id, data) SELECT ?, id, data FROM {:}",
-                        quote_identifier(&remaining.internal_name)
+                        SqlBuffer::quote_identifier(&remaining.internal_name)
                     ),
                     &remaining.name,
                 )
@@ -100,13 +102,39 @@ fn update_tables(db: *mut sqlite::sqlite3, schema: &Schema) -> Result<(), PowerS
     // We cannot have any open queries on sqlite_master at the point that we drop tables, otherwise
     // we get "table is locked" errors.
     for remaining in existing_tables.values() {
-        let q = format!("DROP TABLE {:}", quote_identifier(&remaining.internal_name));
+        let q = format!(
+            "DROP TABLE {:}",
+            SqlBuffer::quote_identifier(&remaining.internal_name)
+        );
         db.exec_safe(&q).into_db_result(db)?;
     }
 
     Ok(())
 }
 
+fn create_index_stmt(table_name: &str, index_name: &str, index: &Index) -> String {
+    let mut sql = SqlBuffer::new();
+    sql.push_str("CREATE INDEX ");
+    let _ = sql.identifier().write_str(&index_name);
+    sql.push_str(" ON ");
+    let _ = sql.identifier().write_str(&table_name);
+    sql.push_char('(');
+    {
+        let mut sql = sql.comma_separated();
+        for indexed_column in &index.columns {
+            let sql = sql.element();
+            sql.json_extract_and_cast("data", &indexed_column.name, &indexed_column.type_name);
+
+            if !indexed_column.ascending {
+                sql.push_str(" DESC");
+            }
+        }
+    }
+    sql.push_char(')');
+
+    sql.sql
+}
+
 fn update_indexes(db: *mut sqlite::sqlite3, schema: &Schema) -> Result<(), PowerSyncError> {
     let mut statements: Vec<String> = alloc::vec![];
     let mut expected_index_names: Vec<String> = vec![];
@@ -136,32 +164,14 @@ fn update_indexes(db: *mut sqlite::sqlite3, schema: &Schema) -> Result<(), Power
                     result
                 };
 
-                let mut column_values: Vec<String> = alloc::vec![];
-                for indexed_column in &index.columns {
-                    let mut value = format!(
-                        "CAST(json_extract(data, {:}) as {:})",
-                        quote_json_path(&indexed_column.name),
-                        &indexed_column.type_name
-                    );
-
-                    if !indexed_column.ascending {
-                        value += " DESC";
-                    }
-
-                    column_values.push(value);
-                }
-
-                let sql = format!(
-                    "CREATE INDEX {} ON {}({})",
-                    quote_identifier(&index_name),
-                    quote_identifier(&table_name),
-                    column_values.join(", ")
-                );
-
+                let sql = create_index_stmt(&table_name, &index_name, index);
                 if existing_sql.is_none() {
                     statements.push(sql);
                 } else if existing_sql != Some(&sql) {
-                    statements.push(format!("DROP INDEX {}", quote_identifier(&index_name)));
+                    statements.push(format!(
+                        "DROP INDEX {}",
+                        SqlBuffer::quote_identifier(&index_name)
+                    ));
                     statements.push(sql);
                 }
 
@@ -190,7 +200,7 @@ SELECT
         while statement.step()? == ResultCode::ROW {
             let name = statement.column_text(0)?;
 
-            statements.push(format!("DROP INDEX {}", quote_identifier(name)));
+            statements.push(format!("DROP INDEX {}", SqlBuffer::quote_identifier(name)));
         }
     }
 
@@ -294,3 +304,40 @@ pub fn register(db: *mut sqlite::sqlite3, state: Rc<DatabaseState>) -> Result<()
 
     Ok(())
 }
+
+#[cfg(test)]
+mod test {
+    use alloc::{string::ToString, vec};
+
+    use crate::schema::table_info::{Index, IndexedColumn};
+
+    use super::create_index_stmt;
+
+    #[test]
+    fn test_create_index() {
+        let stmt = create_index_stmt(
+            "table",
+            "index",
+            &Index {
+                name: "unused".to_string(),
+                columns: vec![
+                    IndexedColumn {
+                        name: "a".to_string(),
+                        ascending: true,
+                        type_name: "text".to_string(),
+                    },
+                    IndexedColumn {
+                        name: "b".to_string(),
+                        ascending: false,
+                        type_name: "integer".to_string(),
+                    },
+                ],
+            },
+        );
+
+        assert_eq!(
+            stmt,
+            r#"CREATE INDEX "index" ON "table"(CAST(json_extract(data, '$.a') as text), CAST(json_extract(data, '$.b') as integer) DESC)"#
+        )
+    }
+}

crates/core/src/schema/table_info.rs

@@ -162,6 +162,12 @@ impl TableInfoFlags {
     }
 
     pub const fn insert_only(self) -> bool {
+        // Note: insert_only is incompatible with local_only. For backwards compatibility, we want
+        // to silently ignore insert_only if local_only is set.
+        if self.local_only() {
+            return false;
+        }
+
         self.0 & Self::INSERT_ONLY != 0
     }
 

crates/core/src/sync/interface.rs

@@ -23,7 +23,7 @@ use serde_json::value::RawValue;
 use sqlite::{ResultCode, Value};
 
 use crate::sync::BucketPriority;
-use crate::util::JsonString;
+use crate::utils::JsonString;
 
 /// Payload provided by SDKs when requesting a sync iteration.
 #[derive(Deserialize)]

crates/core/src/sync/storage_adapter.rs

@@ -18,7 +18,7 @@ use crate::{
         sync_status::{ActiveStreamSubscription, DownloadSyncStatus, SyncPriorityStatus},
     },
     sync_local::{PartialSyncOperation, SyncOperation},
-    util::{JsonString, column_nullable},
+    utils::{JsonString, column_nullable},
 };
 
 use super::{

crates/core/src/sync/subscriptions.rs

@@ -9,7 +9,7 @@ use crate::{
     error::{PSResult, PowerSyncError},
     ext::SafeManagedStmt,
     sync::BucketPriority,
-    util::JsonString,
+    utils::JsonString,
 };
 
 /// A row in the `ps_stream_subscriptions` table.

crates/core/src/sync/sync_status.rs

@@ -24,7 +24,7 @@ use crate::{
         checkpoint::OwnedBucketChecksum, storage_adapter::StorageAdapter,
         subscriptions::LocallyTrackedSubscription,
     },
-    util::JsonString,
+    utils::JsonString,
 };
 
 use super::{