Struct QueryDbConfig 

pub struct QueryDbConfig {
    pub shard_count: usize,
    pub compaction_fragmentation_threshold: f64,
    pub compaction_delta_ratio_threshold: f64,
    pub derived_persistence_filename: String,
    pub enable_background_compaction: bool,
    pub max_entry_size_bytes: usize,
}

Configuration for the incremental query database.

Fields

shard_count: usize

Number of cache shards. Must be a power of two. Default: 64.

compaction_fragmentation_threshold: f64

Arena fragmentation threshold for triggering compaction (0.0–1.0). Default: 0.20 (20%).

compaction_delta_ratio_threshold: f64

Delta buffer ratio threshold for triggering compaction (0.0–1.0). Default: 0.10 (10%).

derived_persistence_filename: String

Path for persisted derived facts (relative to .sqry/graph/). Default: "derived.sqry".

enable_background_compaction: bool

Whether to enable async background compaction. Default: true.

max_entry_size_bytes: usize

Maximum bytes per cached entry (raw key+value postcard encoding).

Entries whose serialized size exceeds this cap are evaluated normally but NOT cached. This prevents a single oversized result from evicting many smaller entries and wasting shard memory.

Default: 1 MiB (1_048_576 bytes = 1 << 20).

Implementations

impl QueryDbConfig

pub fn builder() -> QueryDbConfigBuilder

Returns a builder for fluent configuration.

pub fn from_env() -> Self

Creates a config from environment variables, falling back to defaults.

Recognized variables:

• SQRY_DB_SHARD_COUNT — cache shard count (power of two)
• SQRY_DB_COMPACTION_FRAG — fragmentation threshold (float)
• SQRY_DB_COMPACTION_DELTA — delta ratio threshold (float)
• SQRY_DB_DERIVED_FILE — persistence filename
• SQRY_DB_BG_COMPACTION — 0 to disable background compaction
• SQRY_DB_MAX_ENTRY_SIZE_BYTES — maximum serialized bytes per cached entry; must parse as a positive usize (rejects 0 and non-numeric values — falls back to default of 1 MiB)

Trait Implementations

impl Clone for QueryDbConfig

fn clone(&self) -> QueryDbConfig

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for QueryDbConfig

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

Formats the value using the given formatter.

impl Default for QueryDbConfig

fn default() -> Self

Returns the “default value” for a type.