Struct DefaultPhysicalExprAdapter 

pub struct DefaultPhysicalExprAdapter { /* private fields */ }

Default implementation of PhysicalExprAdapter for rewriting physical expressions to match different schemas.

Overview

DefaultPhysicalExprAdapter rewrites physical expressions to match different schemas, including:

• Type casting: When logical and physical schemas have different types, expressions are automatically wrapped with cast operations. For example, lit(ScalarValue::Int32(123)) = int64_column gets rewritten to lit(ScalarValue::Int32(123)) = cast(int64_column, 'Int32'). Note that this does not attempt to simplify such expressions - that is done by shared simplifiers.

• Missing columns: When a column exists in the logical schema but not in the physical schema, references to it are replaced with null literals.

• Struct field access: Expressions like struct_column.field_that_is_missing_in_schema are rewritten to null when the field doesn’t exist in the physical schema.

• Default column values: Partition column references can be replaced with their literal values when scanning specific partitions. See replace_columns_with_literals for more details.

Example

let factory = DefaultPhysicalExprAdapterFactory;
let adapter = factory.create(Arc::new(logical_file_schema.clone()), Arc::new(physical_file_schema.clone()));
let adapted_predicate = adapter.rewrite(predicate)?;

Implementations

impl DefaultPhysicalExprAdapter

pub fn new( logical_file_schema: SchemaRef, physical_file_schema: SchemaRef, ) -> Self

Create a new instance of the default physical expression adapter.

This adapter rewrites expressions to match the physical schema of the file being scanned, handling type mismatches and missing columns by filling them with default values.

Trait Implementations

impl Clone for DefaultPhysicalExprAdapter

fn clone(&self) -> DefaultPhysicalExprAdapter

Returns a duplicate of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Debug for DefaultPhysicalExprAdapter

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

Formats the value using the given formatter.

impl PhysicalExprAdapter for DefaultPhysicalExprAdapter

fn rewrite(&self, expr: Arc<dyn PhysicalExpr>) -> Result<Arc<dyn PhysicalExpr>>

Rewrite a physical expression to match the target schema.