Struct tidb_query_executors::util::scan_executor::ScanExecutor

pub struct ScanExecutor<S: Storage, I: ScanExecutorImpl> {
    imp: I,
    scanner: RangesScanner<S>,
    is_ended: bool,
}

A shared executor implementation for both table scan and index scan. Implementation differences between table scan and index scan are further given via ScanExecutorImpl.

Fields

imp: I

The internal scanning implementation.

scanner: RangesScanner<S>

The scanner that scans over ranges.

is_ended: bool

A flag indicating whether this executor is ended. When table is drained or there was an error scanning the table, this flag will be set to true and next_batch should be never called again.

Implementations

impl<S: Storage, I: ScanExecutorImpl> ScanExecutor<S, I>

pub fn new(_: ScanExecutorOptions<S, I>) -> Result<Self>

fn fill_column_vec(
    &mut self,
    scan_rows: usize,
    columns: &mut LazyBatchColumnVec
) -> Result<bool>

Fills a column vector and returns whether or not all ranges are drained.

The columns are ensured to be regular even if there are errors during the process.

Trait Implementations

impl<S: Storage, I: ScanExecutorImpl> BatchExecutor for ScanExecutor<S, I>

type StorageStats = S::Statistics

fn schema(&self) -> &[FieldType]

Gets the schema of the output.

fn next_batch(&mut self, scan_rows: usize) -> BatchExecuteResult

Pulls next several rows of data (stored by column).

fn collect_exec_stats(&mut self, dest: &mut ExecuteStats)

Collects execution statistics (including but not limited to metrics and execution summaries) accumulated during execution and prepares for next collection.

fn collect_storage_stats(&mut self, dest: &mut Self::StorageStats)

Collects underlying storage statistics accumulated during execution and prepares for next collection.

fn take_scanned_range(&mut self) -> IntervalRange

fn can_be_cached(&self) -> bool

fn collect_summary(
    self,
    output_index: usize
) -> WithSummaryCollector<ExecSummaryCollectorEnabled, Self> where
    Self: Sized,