Enum FactTableVersionStrategy 

#[non_exhaustive]
pub enum FactTableVersionStrategy {
    Disabled,
    VersionTable,
    TimeBased {
        ttl_seconds: u64,
    },
    SchemaVersion,
}

Versioning strategy for fact table aggregation caching.

Different strategies offer different trade-offs between cache hit rate, data freshness, and operational complexity.

Variants (Non-exhaustive)

Non-exhaustive enums could have additional variants added in future. Therefore, when matching against variants of non-exhaustive enums, an extra wildcard arm must be added to account for any future variants.

Disabled

No caching for aggregations (always query database).

Use when: Real-time accuracy is required. Trade-off: No caching benefit, every query hits database.

VersionTable

Read version from tf_versions table.

Cache key includes the version number, so when version bumps, old cache entries are automatically ignored.

Use when: Data is loaded via ETL/batch processes that can bump versions. Trade-off: Requires discipline to bump version after data changes.

Version Bumping

After loading data, call:

SELECT bump_tf_version('tf_sales');

Or use triggers for automatic bumping (adds write overhead).

TimeBased

Time-based TTL caching.

Cache entries expire after the specified duration regardless of whether the underlying data has changed.

Use when: Some staleness is acceptable (e.g., dashboards). Trade-off: May serve stale data within TTL window.

Fields

ttl_seconds: u64

Cache TTL in seconds.

SchemaVersion

Use schema version only (invalidate on deployment).

Cache is only invalidated when the schema version changes, which typically happens during deployments.

Use when: Fact table data is immutable or append-only and queries always filter to recent data. Trade-off: Stale data until next deployment.

Implementations

impl FactTableVersionStrategy

pub const fn time_based(ttl_seconds: u64) -> Self

Create a time-based strategy with the given TTL.

pub const fn is_caching_enabled(&self) -> bool

Check if caching is enabled for this strategy.

pub const fn ttl_seconds(&self) -> Option<u64>

Get TTL for time-based strategy, if applicable.

Trait Implementations

impl Clone for FactTableVersionStrategy

fn clone(&self) -> FactTableVersionStrategy

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for FactTableVersionStrategy

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

Formats the value using the given formatter.

impl Default for FactTableVersionStrategy

fn default() -> Self

Default strategy is Disabled for safety (no stale data).

impl<'de> Deserialize<'de> for FactTableVersionStrategy

fn deserialize<__D>(__deserializer: __D) -> Result<Self, __D::Error>

where __D: Deserializer<'de>,

Deserialize this value from the given Serde deserializer.

impl PartialEq for FactTableVersionStrategy

fn eq(&self, other: &FactTableVersionStrategy) -> bool

Tests for self and other values to be equal, and is used by ==.

fn ne(&self, other: &Rhs) -> bool

Tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason.

impl Serialize for FactTableVersionStrategy

fn serialize<__S>(&self, __serializer: __S) -> Result<__S::Ok, __S::Error>

where __S: Serializer,

Serialize this value into the given Serde serializer.

impl Eq for FactTableVersionStrategy

impl StructuralPartialEq for FactTableVersionStrategy