Struct BitmapScanStats 

pub struct BitmapScanStats {
    pub candidate_tids: u64,
    pub rows_returned: u64,
    pub pages_touched: u64,
}

Summary statistics the bitmap scan returns alongside its output. Useful for EXPLAIN ANALYZE-style diagnostics and for the planner’s feedback loop when adjusting cost estimates based on actual selectivity.

Fields

candidate_tids: u64

Total candidate TIDs the bitmap contained before fetching.

rows_returned: u64

Rows actually returned (candidates minus tombstones).

pages_touched: u64

Distinct pages touched during the scan. A good proxy for physical I/O: n pages × buffer-pool-hit ratio.

Implementations

impl BitmapScanStats

pub fn survival_ratio(&self) -> f64

Returns the fraction of candidates that survived the tombstone check. Values near 1.0 mean the bitmap is well-pruned; values near 0.0 mean the index was stale and VACUUM should run.

Trait Implementations

impl Clone for BitmapScanStats

fn clone(&self) -> BitmapScanStats

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for BitmapScanStats

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

Formats the value using the given formatter.

impl Default for BitmapScanStats

fn default() -> BitmapScanStats

Returns the “default value” for a type.