Enum AggState 

pub enum AggState {
    CountStar(i64),
    Count {
        non_null: i64,
        distinct: Option<HashSet<DistinctKey>>,
    },
    Sum {
        acc: SumAcc,
        all_null: bool,
    },
    Avg {
        acc: SumAcc,
        n: i64,
    },
    Min(Option<Value>),
    Max(Option<Value>),
}

Per-aggregate accumulator. One instance per (group, projection-slot) pair lives for the duration of the SELECT.

Variants

CountStar(i64)

COUNT(*) — counts every row, including all-NULL rows.

Count

COUNT(col) — counts non-NULL values, optionally with DISTINCT.

Fields

non_null: i64

distinct: Option<HashSet<DistinctKey>>

Sum

SUM(col) — skips NULLs; all_null tracks the SQL semantic that SUM over an all-NULL or empty set yields NULL (not 0).

Fields

acc: SumAcc

all_null: bool

Avg

AVG(col) — always returns Real (or NULL on empty / all-NULL).

Fields

acc: SumAcc

n: i64

Min(Option<Value>)

MIN(col) / MAX(col) — track the running winner (or None until the first non-NULL input).

Max(Option<Value>)

Implementations

impl AggState

pub fn new(call: &AggregateCall) -> Self

Construct the initial accumulator for an aggregate call.

pub fn update(&mut self, value: &Value) -> Result<()>

Fold one row’s value into the accumulator. For COUNT(*), the value is irrelevant — pass anything.

pub fn finalize(&self) -> Value

Produce the final SQL value emitted for this group.

Trait Implementations

impl Clone for AggState

fn clone(&self) -> AggState

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for AggState

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

Formats the value using the given formatter.