Struct SamkhyaTableProvider 

pub struct SamkhyaTableProvider { /* private fields */ }

A TableProvider wrapper that overrides statistics() with samkhya-corrected column statistics while delegating every other method to the inner provider.

Builder

use std::sync::Arc;
use samkhya_datafusion::SamkhyaTableProvider;
use samkhya_core::stats::ColumnStats;

let wrapped = SamkhyaTableProvider::new(Arc::new(inner))
    .with_column_stats(0, ColumnStats::new().with_row_count(999).with_distinct_count(42));

Stats fold semantics

statistics() builds a Statistics whose per-column entries come from the samkhya override map where present, falling back to the inner provider’s stats (or ColumnStatistics::new_unknown() if the inner provider returns None). Table-level num_rows is taken from the override map’s most authoritative row_count: the maximum across all override entries, since samkhya’s per-column stats describe the same underlying relation. If no override carries a row count, the inner provider’s num_rows is preserved.

Implementations

impl SamkhyaTableProvider

pub fn new(inner: Arc<dyn TableProvider>) -> Self

Wrap an existing provider. No overrides are installed until Self::with_column_stats is called.

pub fn with_column_stats(self, col_idx: usize, stats: ColumnStats) -> Self

Install a samkhya override for the column at col_idx.

Indices refer to positions in the inner provider’s SchemaRef. Existing overrides for the same index are replaced.

pub fn stats_call_count(&self) -> usize

Number of times statistics() has been called on this wrapper.

Useful for assertions in integration tests that verify the planner actually consulted the corrected stats.

pub fn overrides(&self) -> &HashMap<usize, ColumnStats>

Borrow the override map. Read-only access for diagnostics.

Trait Implementations

impl Debug for SamkhyaTableProvider

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

Formats the value using the given formatter.

impl TableProvider for SamkhyaTableProvider

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

Fold samkhya overrides into the inner provider’s Statistics.

Schema order is preserved: column i in the returned column_statistics corresponds to field i of self.schema().

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

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

fn table_type(&self) -> TableType

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

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 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 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 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.