Struct ColumnarResult 

pub struct ColumnarResult { /* private fields */ }

Columnar result that stores data column-major and materializes rows lazily.

This is optimized for window functions and other operations that naturally produce column-major output. Instead of allocating millions of Row objects upfront, it stores data as Vec<Value> per column and materializes rows on-demand during iteration.

Key benefits:

• Reduces allocations from O(num_rows) to O(num_columns)
• Reuses a single Row buffer during iteration (zero per-row allocation)
• Natural fit for window function results

The returned row from row() is valid only until the next next() call.

Implementations

impl ColumnarResult

pub fn new(columns: Vec<String>, data: Vec<Vec<Value>>) -> Self

Create a new columnar result from column-major data

Arguments

• columns - Column names (must match data.len())
• data - Column-major data where data[col_idx] contains all values for that column

Panics

Panics if columns.len() != data.len() or if columns have different lengths

pub fn with_arc_columns( columns: CompactArc<Vec<String>>, data: Vec<Vec<Value>>, ) -> Self

Create with CompactArc columns (zero-copy)

pub fn row_count(&self) -> usize

Get the number of rows

pub fn column_count(&self) -> usize

Get the number of columns

Trait Implementations

impl QueryResult for ColumnarResult

fn columns(&self) -> &[String]

Returns the column names in the result

fn columns_arc(&self) -> Option<CompactArc<Vec<String>>>

Returns column names as Arc for zero-copy sharing

fn next(&mut self) -> bool

Moves the cursor to the next row

fn scan(&self, dest: &mut [Value]) -> Result<()>

Scans the current row into the provided values

fn row(&self) -> &Row

Returns the current row directly without copying

fn take_row(&mut self) -> Row

Takes ownership of the current row (avoids clone)

fn close(&mut self) -> Result<()>

Closes the result set and releases resources

fn rows_affected(&self) -> i64

Returns the number of rows affected by an INSERT, UPDATE, or DELETE

fn last_insert_id(&self) -> i64

Returns the last inserted ID for an INSERT operation

fn estimated_count(&self) -> Option<usize>

Returns an estimate of the total number of rows in the result.

fn with_aliases( self: Box<Self>, aliases: FxHashMap<String, String>, ) -> Box<dyn QueryResult>

Sets column aliases for this result

fn try_into_arc_rows(&mut self) -> Option<CompactArc<Vec<Row>>>

Try to extract all rows as CompactArc<Vec<Row>> for zero-copy joins

fn supports_typed_batches(&self) -> bool

Whether the result can yield decoded typed column batches without constructing a row/value object for every result record.

fn typed_batch_fallback_reason(&self) -> Option<TypedBatchFallbackReason>

If supports_typed_batches() is false, return the best semantic reason.

fn next_typed_batch(&mut self) -> Result<Option<TypedColumnBatch>, Error>

Advance to the next typed column batch.

fn last_error(&mut self) -> Option<Error>

Returns a pending error from the last next() call, if any.