Struct QueryStats 

pub struct QueryStats { /* private fields */ }

Implementations

impl QueryStats

pub fn new() -> Self

pub fn len(&self) -> usize

pub fn is_empty(&self) -> bool

pub fn get(&self, sql: &str) -> Option<&QueryStat>

Returns the recorded stat snapshot, if any. Does NOT promote LRU (introspection should be side-effect free).

v7.37.22 (22.6) — sql is normalised before lookup so callers don’t have to know about the normalisation rules.

pub fn iter(&self) -> impl Iterator<Item = (&String, &QueryStat)>

Iterate every recorded entry in deterministic (BTreeMap) order. Used by spg_stat_query virtual table.

pub fn normalize_sql(sql: &str) -> String

v7.37.22 (22.6) — normalise a SQL string for pg_stat_statements grouping. Replaces literal values with $N placeholders so SELECT * FROM t WHERE id = 1 and SELECT * FROM t WHERE id = 2 collapse into the same key (matching PG’s behaviour).

Rules:

• Numeric literals (integer + float) → $N
• Single-quoted string literals (with '' escape) → $N
• NULL / TRUE / FALSE → preserved (PG also preserves these)
• Whitespace runs → single space
• Comments stripped (-- … to EOL; /* … */ block)

Each replaced literal increments N so multi-literal queries get $1, $2, $3. Round-trippable enough that DBAs reading the normalised form can map it back to the original query template.

pub fn record(&mut self, sql: &str, elapsed_us: u64, now_us: u64)

Record one execution. elapsed_us is the wall-clock micros between start and end; now_us is the wall-clock micros at completion (used for last_seen_us).

v7.37.22 (22.6) — the sql key is normalised so distinct literal-bearing instances collapse to a single template.

Row-count is reported via Self::record_with_rows; this shim defaults to 0 for callers that don’t yet plumb the affected / produced row count through.

pub fn record_with_rows( &mut self, sql: &str, elapsed_us: u64, now_us: u64, rows: u64, )

v7.37.22 (22.9) — full record path with row count tracking. rows is the number of rows the executor produced (SELECT result.len()) or affected (INSERT/UPDATE/DELETE affected). Aggregates over the normalised template into total_rows (cumulative) and max_rows (per-call peak).

pub fn clear(&mut self)

v6.5.6 — operator-controlled clear (e.g. for ops resets).

pub fn cap(&self) -> usize

pub fn snapshot(&self) -> Vec<(String, QueryStat)>

Snapshot rows in LRU order (oldest → newest). Used by spg_stat_query ORDER BY default.

Trait Implementations

impl Clone for QueryStats

fn clone(&self) -> QueryStats

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for QueryStats

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

Formats the value using the given formatter.

impl Default for QueryStats

fn default() -> QueryStats

Returns the “default value” for a type.