Struct OptimizerConfig 

#[non_exhaustive]
pub struct OptimizerConfig {
    pub dp_threshold: usize,
    pub index_heat_threshold: f32,
    pub enable_pushdown: bool,
    pub default_filter_selectivity: f64,
    pub transfer_cost_multiplier: f64,
    pub default_bytes_per_row: u64,
}

Configuration for query optimization.

Controls optimizer behavior including thresholds for algorithm selection and feature toggles.

Fields (Non-exhaustive)

Non-exhaustive structs could have additional fields added in future. Therefore, non-exhaustive structs cannot be constructed in external crates using the traditional Struct { .. } syntax; cannot be matched against without a wildcard ..; and struct update syntax will not work.

dp_threshold: usize

Maximum number of relations for exhaustive dynamic programming.

When a query involves more relations than this threshold, the optimizer switches to a greedy algorithm for join ordering to avoid exponential time complexity. Default: 10 relations.

index_heat_threshold: f32

Heat threshold for recommending index creation.

Relations with access heat above this threshold are candidates for index building to accelerate future queries. Default: 0.7.

enable_pushdown: bool

Enable predicate pushdown optimization.

When enabled, filter predicates are pushed down through projections and joins to be applied as early as possible. Default: true.

default_filter_selectivity: f64

Default selectivity for filters when no statistics are available.

Used as a fallback when column statistics cannot provide a better estimate. Default: 0.1 (10% selectivity).

transfer_cost_multiplier: f64

Cost multiplier for GPU-to-host data transfers.

Transfers are expensive operations; this multiplier reflects the relative cost compared to local GPU operations. Default: 100.0.

default_bytes_per_row: u64

Bytes per row used for GPU memory estimation when schema is unknown.

Default: 32 bytes (assumes 4 columns at 8 bytes each on average).

Trait Implementations

impl Clone for OptimizerConfig

fn clone(&self) -> OptimizerConfig

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for OptimizerConfig

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

Formats the value using the given formatter.

impl Default for OptimizerConfig

fn default() -> Self

Returns the “default value” for a type.