Struct ClickHouseTableProvider 

pub struct ClickHouseTableProvider { /* private fields */ }

A custom TableProvider for remove ClickHouse tables.

Implementations

impl ClickHouseTableProvider

pub async fn try_new( pool: Arc<ClickHouseConnectionPool>, table: TableReference, ) -> Result<Self>

Creates a new TableProvider, fetching the schema from ClickHouse if not provided.

Errors

• Returns an error if the SQLTable creation fails.

pub fn new_with_schema_unchecked( pool: Arc<ClickHouseConnectionPool>, table: TableReference, schema: SchemaRef, ) -> Self

Creates a new TableProvider with a pre-fetched schema. The underlying SqlTable will not verify if the table exists nor if the schema is accurate. To catch any errors in these cases, use try_new.

pub fn with_exprs(self, exprs: Vec<Expr>) -> Self

pub fn with_coercion(self, coerce: bool) -> Self

Whether to coerce the RecordBatches returned by SQLExecutor::execute using the generated LogicalPlan’s schema.

pub fn reader(&self) -> &SqlTable

pub fn pool(&self) -> &Arc<ClickHouseConnectionPool>

pub fn coerce_schema(&self) -> bool

pub fn execute_sql( &self, query: &str, schema: SchemaRef, ) -> Result<SendableRecordBatchStream>

Executes a SQL query and returns a stream of record batches.

This method is exposed so that federation is not required to run sql using this table provider.

Errors

• Returns an error if the connection pool fails to connect.
• Returns an error if the query execution fails.

pub fn unique_context(&self) -> String

Provide the unique context for this table provider.

This method is provided publicly to allow access to whether this provider accesses the same underlying ClickHouse server as another, without relying on federation.

Trait Implementations

impl Debug for ClickHouseTableProvider

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl TableProvider for ClickHouseTableProvider

fn as_any(&self) -> &dyn Any

Returns the table provider as Any so that it can be downcast to a specific implementation.

fn schema(&self) -> SchemaRef

Get a reference to the schema for this table

fn table_type(&self) -> TableType

Get the type of this table for metadata/catalog purposes.

fn supports_filters_pushdown( &self, filters: &[&Expr], ) -> Result<Vec<TableProviderFilterPushDown>>

Specify if DataFusion should provide filter expressions to the TableProvider to apply during the scan.

fn scan<'life0, 'life1, 'life2, 'life3, 'async_trait>( &'life0 self, state: &'life1 dyn Session, projection: Option<&'life2 Vec<usize>>, filters: &'life3 [Expr], limit: Option<usize>, ) -> Pin<Box<dyn Future<Output = Result<Arc<dyn ExecutionPlan>>> + Send + 'async_trait>>

where Self: 'async_trait, 'life0: 'async_trait, 'life1: 'async_trait, 'life2: 'async_trait, 'life3: 'async_trait,

Create an ExecutionPlan for scanning the table with optionally specified projection, filter and limit, described below.

fn insert_into<'life0, 'life1, 'async_trait>( &'life0 self, _state: &'life1 dyn Session, input: Arc<dyn ExecutionPlan>, insert_op: InsertOp, ) -> Pin<Box<dyn Future<Output = Result<Arc<dyn ExecutionPlan>>> + Send + 'async_trait>>

where Self: 'async_trait, 'life0: 'async_trait, 'life1: 'async_trait,

Return an ExecutionPlan to insert data into this table, if supported.

fn constraints(&self) -> Option<&Constraints>

Get a reference to the constraints of the table. Returns:

fn get_table_definition(&self) -> Option<&str>

Get the create statement used to create this table, if available.

fn get_logical_plan(&self) -> Option<Cow<'_, LogicalPlan>>

Get the LogicalPlan of this table, if available.

fn get_column_default(&self, _column: &str) -> Option<&Expr>

Get the default value for a column, if available.

fn statistics(&self) -> Option<Statistics>

Get statistics for this table, if available Although not presently used in mainline DataFusion, this allows implementation specific behavior for downstream repositories, in conjunction with specialized optimizer rules to perform operations such as re-ordering of joins.