Enum UnionMode 

pub enum UnionMode {
    Parallel,
    Sequential,
}

Controls how union operations combine multiple index scans for OR conditions.

When executing disjunctive (OR) queries across multiple indexes, results must be combined. This enum allows choosing between parallel and sequential execution strategies based on runtime requirements.

Variants

Parallel

Use standard UnionExec with parallel execution.

This mode spawns Tokio tasks via JoinSet::spawn() to process partitions concurrently. Best for Tokio-based runtimes with good parallelism support.

Warning: This mode will panic in non-Tokio async runtimes.

Sequential

Use SequentialUnionExec with single-threaded sequential execution.

This mode processes all input partitions sequentially in a single stream without spawning any tasks. Required for non-Tokio runtimes such as custom async executors that don’t support Tokio task spawning.

Trait Implementations

impl Clone for UnionMode

fn clone(&self) -> UnionMode

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for UnionMode

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

Formats the value using the given formatter.

impl Default for UnionMode

fn default() -> UnionMode

Returns the “default value” for a type.

impl Copy for UnionMode