feat: materialized view declarations on local tables (#3930)

A materialized view is a table whose contents are defined by a query
over
one source table and maintained by refresh rather than by writes.

The declaration half: create_materialized_view(name, source) resolves a
projected, filtered and limited definition against the source schema --
output types come from the DataFusion planner, never the caller -- and
commits an empty table carrying it as kind-tagged JSON in schema
metadata.
The tag lets a kind added later read back as a view this version cannot
refresh rather than as a plain table. Views open and list as ordinary
tables.

Sources must have stable row ids, checked here because the property
cannot
be enabled later: each view row records its source row in
__source_row_id,
and that provenance survives compactions, updates and deletes only when
row
ids are stable.

A view inherits the metadata describing its columns and none governing
how a
table is written, so blob markers carry through while declarations its
always-nullable fields would contradict are stripped. Embedding
configuration is rewritten to the view's column names, and dropped where
it
does not project both ends of a function.


<sub>Stack created with <a
href="https://github.com/github/gh-stack">GitHub Stacks CLI</a> • <a
href="https://gh.io/stacks-feedback">Give Feedback 💬</a></sub>

rust/lancedb/src/connection.rs

@@ -41,7 +41,7 @@ use lance_io::object_store::{StorageOptionsAccessor, StorageOptionsProvider};
 
 mod create_table;
 
-fn merge_storage_options(
+pub(crate) fn merge_storage_options(
     store_params: &mut ObjectStoreParams,
     pairs: impl IntoIterator<Item = (String, String)>,
 ) {

rust/lancedb/src/database/listing.rs

@@ -765,60 +765,13 @@ impl ListingDatabase {
         }
     }
 
-    /// Extract storage option overrides from the request
-    fn extract_storage_overrides(
-        &self,
-        request: &CreateTableRequest,
-    ) -> Result<(Option<LanceFileVersion>, Option<bool>, Option<bool>)> {
-        let storage_options = request
-            .write_options
-            .lance_write_params
-            .as_ref()
-            .and_then(|p| p.store_params.as_ref())
-            .and_then(|sp| sp.storage_options());
-
-        let storage_version_override = storage_options
-            .and_then(|opts| opts.get(OPT_NEW_TABLE_STORAGE_VERSION))
-            .map(|s| s.parse::<LanceFileVersion>())
-            .transpose()?;
-
-        let v2_manifest_override = storage_options
-            .and_then(|opts| opts.get(OPT_NEW_TABLE_V2_MANIFEST_PATHS))
-            .map(|s| s.parse::<bool>())
-            .transpose()
-            .map_err(|_| Error::InvalidInput {
-                message: "enable_v2_manifest_paths must be a boolean".to_string(),
-            })?;
-
-        let stable_row_ids_override = storage_options
-            .and_then(|opts| opts.get(OPT_NEW_TABLE_ENABLE_STABLE_ROW_IDS))
-            .map(|s| s.parse::<bool>())
-            .transpose()
-            .map_err(|_| Error::InvalidInput {
-                message: "enable_stable_row_ids must be a boolean".to_string(),
-            })?;
-
-        Ok((
-            storage_version_override,
-            v2_manifest_override,
-            stable_row_ids_override,
-        ))
-    }
-
     /// Prepare write parameters for table creation
     fn prepare_write_params(
         &self,
         request: &CreateTableRequest,
-        storage_version_override: Option<LanceFileVersion>,
-        v2_manifest_override: Option<bool>,
-        stable_row_ids_override: Option<bool>,
+        mut write_params: lance::dataset::WriteParams,
+        overrides: NewTableConfig,
     ) -> lance::dataset::WriteParams {
-        let mut write_params = request
-            .write_options
-            .lance_write_params
-            .clone()
-            .unwrap_or_default();
-
         // Only modify the storage options if we actually have something to
         // inherit. There is a difference between storage_options=None and
         // storage_options=Some({}). Using storage_options=None will cause the
@@ -842,18 +795,21 @@ impl ListingDatabase {
             store_params.storage_options_accessor = Some(Arc::new(accessor));
         }
 
-        write_params.data_storage_version = storage_version_override
+        write_params.data_storage_version = overrides
+            .data_storage_version
             .or(write_params.data_storage_version)
             .or(self.new_table_config.data_storage_version);
 
-        if let Some(enable_v2_manifest_paths) =
-            v2_manifest_override.or(self.new_table_config.enable_v2_manifest_paths)
+        if let Some(enable_v2_manifest_paths) = overrides
+            .enable_v2_manifest_paths
+            .or(self.new_table_config.enable_v2_manifest_paths)
         {
             write_params.enable_v2_manifest_paths = enable_v2_manifest_paths;
         }
 
         let data_schema = request.data.arrow_schema();
-        if let Some(enable_stable_row_ids) = stable_row_ids_override
+        if let Some(enable_stable_row_ids) = overrides
+            .enable_stable_row_ids
             .or(self.new_table_config.enable_stable_row_ids)
             .or(has_blob_columns(&data_schema).then_some(true))
         {
@@ -1048,15 +1004,13 @@ impl Database for ListingDatabase {
             .clone()
             .unwrap_or_else(|| self.table_uri(&request.name).unwrap());
 
-        let (storage_version_override, v2_manifest_override, stable_row_ids_override) =
-            self.extract_storage_overrides(&request)?;
-
-        let write_params = self.prepare_write_params(
-            &request,
-            storage_version_override,
-            v2_manifest_override,
-            stable_row_ids_override,
-        );
+        let mut write_params = request
+            .write_options
+            .lance_write_params
+            .clone()
+            .unwrap_or_default();
+        let overrides = take_request_creation_overrides(&mut write_params)?;
+        let write_params = self.prepare_write_params(&request, write_params, overrides);
 
         let data_schema = request.data.arrow_schema();
 
@@ -1288,8 +1242,232 @@ impl Database for ListingDatabase {
     }
 }
 
+/// Parse the request-level `new_table_*` creation keys into overrides and
+/// strip them from the store options in one step: every create path that
+/// honors them must also keep them out of the object store.
+pub(crate) fn take_request_creation_overrides(
+    params: &mut lance::dataset::WriteParams,
+) -> Result<NewTableConfig> {
+    let storage_options = params
+        .store_params
+        .as_ref()
+        .and_then(|sp| sp.storage_options());
+    let overrides = NewTableConfig {
+        data_storage_version: storage_options
+            .and_then(|opts| opts.get(OPT_NEW_TABLE_STORAGE_VERSION))
+            .map(|s| s.parse::<LanceFileVersion>())
+            .transpose()?,
+        enable_v2_manifest_paths: storage_options
+            .and_then(|opts| opts.get(OPT_NEW_TABLE_V2_MANIFEST_PATHS))
+            .map(|s| s.parse::<bool>())
+            .transpose()
+            .map_err(|_| Error::InvalidInput {
+                message: "enable_v2_manifest_paths must be a boolean".to_string(),
+            })?,
+        enable_stable_row_ids: storage_options
+            .and_then(|opts| opts.get(OPT_NEW_TABLE_ENABLE_STABLE_ROW_IDS))
+            .map(|s| s.parse::<bool>())
+            .transpose()
+            .map_err(|_| Error::InvalidInput {
+                message: "enable_stable_row_ids must be a boolean".to_string(),
+            })?,
+    };
+    if let Some(store_params) = params.store_params.as_mut() {
+        strip_new_table_creation_keys(store_params);
+    }
+    Ok(overrides)
+}
+
+/// Strip the `new_table_*` creation keys from request store options: they are
+/// creation config, not credentials, and left in place they fork a fresh
+/// store connection for the request.
+fn strip_new_table_creation_keys(store_params: &mut ObjectStoreParams) {
+    let mut options = store_params.storage_options().cloned().unwrap_or_default();
+    let mut removed = false;
+    for key in [
+        OPT_NEW_TABLE_STORAGE_VERSION,
+        OPT_NEW_TABLE_V2_MANIFEST_PATHS,
+        OPT_NEW_TABLE_ENABLE_STABLE_ROW_IDS,
+    ] {
+        removed |= options.remove(key).is_some();
+    }
+    if !removed {
+        return;
+    }
+    let provider = store_params
+        .storage_options_accessor
+        .as_ref()
+        .and_then(|accessor| accessor.provider().cloned());
+    store_params.storage_options_accessor = match (options.is_empty(), provider) {
+        (true, None) => None,
+        (true, Some(provider)) => Some(Arc::new(StorageOptionsAccessor::with_provider(provider))),
+        (false, Some(provider)) => Some(Arc::new(
+            StorageOptionsAccessor::with_initial_and_provider(options, provider),
+        )),
+        (false, None) => Some(Arc::new(StorageOptionsAccessor::with_static_options(
+            options,
+        ))),
+    };
+}
+
 #[cfg(test)]
 mod tests {
+    #[tokio::test]
+    async fn request_level_creation_keys_do_not_fork_the_store() {
+        use crate::query::ExecutableQuery;
+        use futures::TryStreamExt;
+
+        let db = crate::connect("memory://").execute().await.unwrap();
+        let batch = arrow_array::record_batch!(("x", Int32, [1, 2])).unwrap();
+        let store_params = ObjectStoreParams {
+            storage_options_accessor: Some(Arc::new(StorageOptionsAccessor::with_static_options(
+                HashMap::from([(
+                    OPT_NEW_TABLE_ENABLE_STABLE_ROW_IDS.to_string(),
+                    "true".to_string(),
+                )]),
+            ))),
+            ..Default::default()
+        };
+        db.create_table("t", batch)
+            .write_options(crate::table::WriteOptions {
+                lance_write_params: Some(lance::dataset::WriteParams {
+                    store_params: Some(store_params),
+                    ..Default::default()
+                }),
+            })
+            .execute()
+            .await
+            .unwrap();
+
+        let table = db.open_table("t").execute().await.unwrap();
+        let rows: usize = table
+            .query()
+            .execute()
+            .await
+            .unwrap()
+            .try_collect::<Vec<_>>()
+            .await
+            .unwrap()
+            .iter()
+            .map(|b| b.num_rows())
+            .sum();
+        assert_eq!(rows, 2, "the table must live in the session's store");
+    }
+
+    mod strip_new_table_creation_keys {
+        use super::super::*;
+
+        #[derive(Debug)]
+        struct EmptyProvider;
+
+        #[async_trait::async_trait]
+        impl StorageOptionsProvider for EmptyProvider {
+            async fn fetch_storage_options(
+                &self,
+            ) -> lance_core::Result<Option<HashMap<String, String>>> {
+                Ok(Some(HashMap::new()))
+            }
+
+            fn provider_id(&self) -> String {
+                "empty-test-provider".into()
+            }
+        }
+
+        fn params_with_static(options: &[(&str, &str)]) -> ObjectStoreParams {
+            ObjectStoreParams {
+                storage_options_accessor: Some(Arc::new(
+                    StorageOptionsAccessor::with_static_options(
+                        options
+                            .iter()
+                            .map(|(k, v)| (k.to_string(), v.to_string()))
+                            .collect(),
+                    ),
+                )),
+                ..Default::default()
+            }
+        }
+
+        #[test]
+        fn creation_keys_are_removed_and_store_keys_kept() {
+            let mut params = params_with_static(&[
+                ("region", "us-west-2"),
+                (OPT_NEW_TABLE_ENABLE_STABLE_ROW_IDS, "true"),
+            ]);
+            strip_new_table_creation_keys(&mut params);
+            let options = params.storage_options().cloned().unwrap();
+            assert_eq!(options.get("region").map(String::as_str), Some("us-west-2"));
+            assert!(!options.contains_key(OPT_NEW_TABLE_ENABLE_STABLE_ROW_IDS));
+
+            // Creation keys alone: no accessor survives to fork a store.
+            let mut params = params_with_static(&[(OPT_NEW_TABLE_ENABLE_STABLE_ROW_IDS, "true")]);
+            strip_new_table_creation_keys(&mut params);
+            assert!(params.storage_options_accessor.is_none());
+        }
+
+        /// A provider must survive every shape of strip: untouched accessors
+        /// keep their identity, emptied ones still fetch, and residual
+        /// statics ride along.
+        #[test]
+        fn provider_accessors_survive_the_strip() {
+            let accessor = Arc::new(StorageOptionsAccessor::with_provider(Arc::new(
+                EmptyProvider,
+            )));
+            let mut params = ObjectStoreParams {
+                storage_options_accessor: Some(accessor.clone()),
+                ..Default::default()
+            };
+            strip_new_table_creation_keys(&mut params);
+            assert!(Arc::ptr_eq(
+                params.storage_options_accessor.as_ref().unwrap(),
+                &accessor
+            ));
+
+            let mut params = ObjectStoreParams {
+                storage_options_accessor: Some(Arc::new(
+                    StorageOptionsAccessor::with_initial_and_provider(
+                        HashMap::from([
+                            ("region".to_string(), "us-west-2".to_string()),
+                            (
+                                OPT_NEW_TABLE_ENABLE_STABLE_ROW_IDS.to_string(),
+                                "true".to_string(),
+                            ),
+                        ]),
+                        Arc::new(EmptyProvider),
+                    ),
+                )),
+                ..Default::default()
+            };
+            strip_new_table_creation_keys(&mut params);
+            let accessor = params.storage_options_accessor.unwrap();
+            assert!(accessor.has_provider());
+            assert_eq!(
+                accessor
+                    .initial_storage_options()
+                    .and_then(|o| o.get("region").cloned())
+                    .as_deref(),
+                Some("us-west-2")
+            );
+
+            // Emptied entirely: a first-fetch accessor, not one caching {}.
+            let mut params = ObjectStoreParams {
+                storage_options_accessor: Some(Arc::new(
+                    StorageOptionsAccessor::with_initial_and_provider(
+                        HashMap::from([(
+                            OPT_NEW_TABLE_ENABLE_STABLE_ROW_IDS.to_string(),
+                            "true".to_string(),
+                        )]),
+                        Arc::new(EmptyProvider),
+                    ),
+                )),
+                ..Default::default()
+            };
+            strip_new_table_creation_keys(&mut params);
+            let accessor = params.storage_options_accessor.unwrap();
+            assert!(accessor.has_provider());
+            assert!(accessor.initial_storage_options().is_none());
+        }
+    }
+
     use super::*;
     use crate::Table;
     use crate::arrow::{SendableRecordBatchStream, SimpleRecordBatchStream};

rust/lancedb/src/database/namespace.rs

@@ -26,10 +26,7 @@ use lance_table::io::commit::external_manifest::ExternalManifestCommitHandler;
 use crate::blob::{ensure_blob_storage_version, has_blob_columns};
 use crate::connection::NamespaceClientPushdownOperation;
 use crate::database::ReadConsistency;
-use crate::database::listing::{
-    NewTableConfig, OPT_NEW_TABLE_ENABLE_STABLE_ROW_IDS, OPT_NEW_TABLE_STORAGE_VERSION,
-    OPT_NEW_TABLE_V2_MANIFEST_PATHS,
-};
+use crate::database::listing::{NewTableConfig, take_request_creation_overrides};
 use crate::database::read_freshness::{
     FreshnessBaselines, ReadFreshnessContextProvider, TableFreshness,
 };
@@ -197,69 +194,28 @@ impl LanceNamespaceDatabase {
         TableFreshness::new(self.freshness_baselines.clone(), key)
     }
 
-    fn extract_storage_overrides(
-        &self,
-        request: &DbCreateTableRequest,
-    ) -> Result<(
-        Option<lance_file::version::LanceFileVersion>,
-        Option<bool>,
-        Option<bool>,
-    )> {
-        let storage_options = request
-            .write_options
-            .lance_write_params
-            .as_ref()
-            .and_then(|p| p.store_params.as_ref())
-            .and_then(|sp| sp.storage_options());
-
-        let storage_version_override = storage_options
-            .and_then(|opts| opts.get(OPT_NEW_TABLE_STORAGE_VERSION))
-            .map(|s| s.parse::<lance_file::version::LanceFileVersion>())
-            .transpose()?;
-
-        let v2_manifest_override = storage_options
-            .and_then(|opts| opts.get(OPT_NEW_TABLE_V2_MANIFEST_PATHS))
-            .map(|s| s.parse::<bool>())
-            .transpose()
-            .map_err(|_| Error::InvalidInput {
-                message: "enable_v2_manifest_paths must be a boolean".to_string(),
-            })?;
-
-        let stable_row_ids_override = storage_options
-            .and_then(|opts| opts.get(OPT_NEW_TABLE_ENABLE_STABLE_ROW_IDS))
-            .map(|s| s.parse::<bool>())
-            .transpose()
-            .map_err(|_| Error::InvalidInput {
-                message: "enable_stable_row_ids must be a boolean".to_string(),
-            })?;
-
-        Ok((
-            storage_version_override,
-            v2_manifest_override,
-            stable_row_ids_override,
-        ))
-    }
-
     fn apply_new_table_config(
         &self,
         params: &mut lance::dataset::WriteParams,
         request: &DbCreateTableRequest,
     ) -> Result<()> {
-        let (storage_version_override, v2_manifest_override, stable_row_ids_override) =
-            self.extract_storage_overrides(request)?;
+        let overrides = take_request_creation_overrides(params)?;
 
-        params.data_storage_version = storage_version_override
+        params.data_storage_version = overrides
+            .data_storage_version
             .or(params.data_storage_version)
             .or(self.new_table_config.data_storage_version);
 
-        if let Some(enable_v2_manifest_paths) =
-            v2_manifest_override.or(self.new_table_config.enable_v2_manifest_paths)
+        if let Some(enable_v2_manifest_paths) = overrides
+            .enable_v2_manifest_paths
+            .or(self.new_table_config.enable_v2_manifest_paths)
         {
             params.enable_v2_manifest_paths = enable_v2_manifest_paths;
         }
 
         let data_schema = request.data.schema();
-        if let Some(enable_stable_row_ids) = stable_row_ids_override
+        if let Some(enable_stable_row_ids) = overrides
+            .enable_stable_row_ids
             .or(self.new_table_config.enable_stable_row_ids)
             .or(has_blob_columns(data_schema.as_ref()).then_some(true))
         {
@@ -644,6 +600,146 @@ mod tests {
         RecordBatch::try_new(schema, vec![Arc::new(id_array), Arc::new(name_array)]).unwrap()
     }
 
+    /// The shared parse-and-sanitize boundary is wired into this path: the
+    /// request-level creation key must act as an override (the strip itself
+    /// is covered by the listing tests).
+    #[tokio::test]
+    async fn request_level_creation_keys_are_taken_as_overrides() {
+        use crate::database::listing::OPT_NEW_TABLE_ENABLE_STABLE_ROW_IDS;
+
+        let tmp_dir = tempdir().unwrap();
+        let mut properties = HashMap::new();
+        properties.insert(
+            "root".to_string(),
+            tmp_dir.path().to_str().unwrap().to_string(),
+        );
+        let db = connect_namespace("dir", properties)
+            .execute()
+            .await
+            .unwrap();
+
+        let store_params = ObjectStoreParams {
+            storage_options_accessor: Some(Arc::new(StorageOptionsAccessor::with_static_options(
+                HashMap::from([(
+                    OPT_NEW_TABLE_ENABLE_STABLE_ROW_IDS.to_string(),
+                    "true".to_string(),
+                )]),
+            ))),
+            ..Default::default()
+        };
+        let table = db
+            .create_table("t", create_test_data())
+            .write_options(crate::table::WriteOptions {
+                lance_write_params: Some(lance::dataset::WriteParams {
+                    store_params: Some(store_params),
+                    ..Default::default()
+                }),
+            })
+            .execute()
+            .await
+            .unwrap();
+        let native = table.as_native().unwrap();
+        assert!(
+            native
+                .dataset
+                .get()
+                .await
+                .unwrap()
+                .manifest
+                .uses_stable_row_ids(),
+            "the creation key must be honored as an override"
+        );
+
+        let table = db.open_table("t").execute().await.unwrap();
+        let rows: usize = table
+            .query()
+            .execute()
+            .await
+            .unwrap()
+            .try_collect::<Vec<_>>()
+            .await
+            .unwrap()
+            .iter()
+            .map(|b| b.num_rows())
+            .sum();
+        assert_eq!(rows, 5);
+    }
+
+    /// Sanitation on this path: apply must strip the creation keys from the
+    /// store options while genuine options and the provider survive.
+    #[tokio::test]
+    async fn apply_new_table_config_sanitizes_request_store_options() {
+        use crate::database::listing::OPT_NEW_TABLE_ENABLE_STABLE_ROW_IDS;
+        use lance_io::object_store::StorageOptionsProvider;
+
+        #[derive(Debug)]
+        struct EmptyProvider;
+
+        #[async_trait::async_trait]
+        impl StorageOptionsProvider for EmptyProvider {
+            async fn fetch_storage_options(
+                &self,
+            ) -> lance_core::Result<Option<HashMap<String, String>>> {
+                Ok(Some(HashMap::new()))
+            }
+
+            fn provider_id(&self) -> String {
+                "empty-test-provider".into()
+            }
+        }
+
+        let tmp_dir = tempdir().unwrap();
+        let mut properties = HashMap::new();
+        properties.insert(
+            "root".to_string(),
+            tmp_dir.path().to_str().unwrap().to_string(),
+        );
+        let db = LanceNamespaceDatabase::connect_with_new_table_config(
+            "dir",
+            properties,
+            HashMap::new(),
+            None,
+            None,
+            HashSet::new(),
+            NewTableConfig::default(),
+        )
+        .await
+        .unwrap();
+
+        let request = DbCreateTableRequest::new("t".to_string(), Box::new(create_test_data()));
+        let mut params = lance::dataset::WriteParams {
+            store_params: Some(ObjectStoreParams {
+                storage_options_accessor: Some(Arc::new(
+                    StorageOptionsAccessor::with_initial_and_provider(
+                        HashMap::from([
+                            ("region".to_string(), "us-west-2".to_string()),
+                            (
+                                OPT_NEW_TABLE_ENABLE_STABLE_ROW_IDS.to_string(),
+                                "true".to_string(),
+                            ),
+                        ]),
+                        Arc::new(EmptyProvider),
+                    ),
+                )),
+                ..Default::default()
+            }),
+            ..Default::default()
+        };
+        db.apply_new_table_config(&mut params, &request).unwrap();
+
+        assert!(params.enable_stable_row_ids);
+        let store_params = params.store_params.unwrap();
+        let options = store_params.storage_options().cloned().unwrap();
+        assert!(!options.contains_key(OPT_NEW_TABLE_ENABLE_STABLE_ROW_IDS));
+        assert_eq!(options.get("region").map(String::as_str), Some("us-west-2"));
+        assert!(
+            store_params
+                .storage_options_accessor
+                .unwrap()
+                .has_provider()
+        );
+    }
+
     #[tokio::test]
     async fn test_namespace_connection_simple() {
         // Test that namespace connections work with simple connect_namespace(impl_type, properties)

rust/lancedb/src/error.rs

@@ -77,6 +77,8 @@ pub enum Error {
     ColumnAlreadyExists { name: String },
     #[snafu(display("Column '{name}' is not a computed column"))]
     NotAComputedColumn { name: String },
+    #[snafu(display("Table '{name}' is not a materialized view"))]
+    NotAMaterializedView { name: String },
     #[snafu(display("Invalid expression for column '{column}': {message}"))]
     InvalidExpression { column: String, message: String },
 

rust/lancedb/src/lib.rs

@@ -186,6 +186,7 @@ pub mod index;
 pub mod io;
 pub mod ipc;
 pub mod job;
+pub mod materialized_view;
 #[cfg(feature = "metrics-otel")]
 pub mod metrics_otel;
 #[cfg(feature = "polars")]
@@ -210,6 +211,7 @@ pub use function::FunctionVersion;
 pub use job::Job;
 use lance_index::vector::ApproxMode as LanceApproxMode;
 use lance_linalg::distance::DistanceType as LanceDistanceType;
+pub use materialized_view::{MaterializedView, MaterializedViewDefinition};
 /// Re-export of the [`metrics`](https://docs.rs/metrics) crate facade. Enable
 /// the `metrics` feature to publish LanceDB's internal metrics; install any
 /// `metrics`-compatible recorder to collect them. See also [`metrics_otel`] for

rust/lancedb/src/remote/table.rs

@@ -10410,6 +10410,20 @@ mod tests {
         );
     }
 
+    #[tokio::test]
+    async fn test_materialized_view_refused_without_a_request() {
+        // Materialized views are local-only. The table-level entry the
+        // bindings use must refuse a remote table before reading its schema,
+        // so the panicking handler is the assertion.
+        let table = Table::new_with_handler("my_table", |request| -> http::Response<String> {
+            panic!("unexpected request: {}", request.url().path())
+        });
+        let err = crate::MaterializedView::from_table(table)
+            .await
+            .unwrap_err();
+        assert!(matches!(err, Error::NotSupported { .. }), "got {err:?}");
+    }
+
     #[tokio::test]
     async fn test_create_branch_empty_name_rejected_client_side() {
         use lance::dataset::refs::Ref;

rust/lancedb/src/table.rs

@@ -1066,6 +1066,11 @@ impl Table {
         self.database.as_ref().unwrap()
     }
 
+    /// The database this handle was opened through, when it was.
+    pub fn database_opt(&self) -> Option<&Arc<dyn Database>> {
+        self.database.as_ref()
+    }
+
     pub fn embedding_registry(&self) -> &Arc<dyn EmbeddingRegistry> {
         &self.embedding_registry
     }

rust/lancedb/src/table/refresh.rs

@@ -193,7 +193,7 @@ fn declared_expression(dataset: &Dataset, column: &str) -> Result<String> {
 ///
 /// Lance's dialect delimits with backticks, so a double-quoted name would
 /// parse as a string literal rather than a column.
-fn quote_identifier(name: &str) -> String {
+pub(crate) fn quote_identifier(name: &str) -> String {
     format!("`{}`", name.replace('`', "``"))
 }