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EngineRules

nodedb_sql::engine_rules

Trait EngineRules 

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pub trait EngineRules {

Show 14 methods    // Required methods
    fn plan_insert(&self, params: InsertParams) -> Result<Vec<SqlPlan>>;
    fn plan_insert_select(
        &self,
        params: InsertSelectParams,
    ) -> Result<Vec<SqlPlan>>;
    fn plan_upsert(&self, params: UpsertParams) -> Result<Vec<SqlPlan>>;
    fn plan_scan(&self, params: ScanParams) -> Result<SqlPlan>;
    fn plan_point_get(&self, params: PointGetParams) -> Result<SqlPlan>;
    fn plan_update(&self, params: UpdateParams) -> Result<Vec<SqlPlan>>;
    fn plan_update_from(&self, params: UpdateFromParams) -> Result<Vec<SqlPlan>>;
    fn plan_delete(&self, params: DeleteParams) -> Result<Vec<SqlPlan>>;
    fn plan_truncate(&self, params: TruncateParams) -> Result<Vec<SqlPlan>>;
    fn plan_aggregate(&self, params: AggregateParams) -> Result<SqlPlan>;
    fn plan_merge(&self, params: MergeParams) -> Result<Vec<SqlPlan>>;
    fn accepts_undeclared_columns(&self) -> bool;

    // Provided methods
    fn implicit_columns(&self) -> &'static [&'static str] { ... }
    fn value_column_name_is_free(&self) -> bool { ... }

}
Expand description

Engine-specific planning rules.

Each engine type implements this trait to produce the correct SqlPlan variant for each operation, or return an error if the operation is not supported. This is the single source of truth for operation routing — no downstream code should ever check engine type to decide routing.

Required Methods§

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fn plan_insert(&self, params: InsertParams) -> Result<Vec<SqlPlan>>

Plan an INSERT. Returns Err if the engine does not support inserts (e.g. timeseries routes to TimeseriesIngest instead).

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fn plan_insert_select(&self, params: InsertSelectParams) -> Result<Vec<SqlPlan>>

Plan an INSERT ... SELECT into a collection on this engine. The Control Plane copies the rows and gives each a fresh surrogate, which the document engines support. Every other engine returns Err(SqlError::Unsupported).

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fn plan_upsert(&self, params: UpsertParams) -> Result<Vec<SqlPlan>>

Plan an UPSERT (insert-or-merge). Returns Err for append-only or columnar engines that don’t support merge semantics.

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fn plan_scan(&self, params: ScanParams) -> Result<SqlPlan>

Plan a table scan (SELECT without point-get optimization).

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fn plan_point_get(&self, params: PointGetParams) -> Result<SqlPlan>

Plan a point lookup by primary key. Returns Err for engines that don’t support O(1) key lookups (e.g. timeseries).

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fn plan_update(&self, params: UpdateParams) -> Result<Vec<SqlPlan>>

Plan an UPDATE. Returns Err for append-only engines.

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fn plan_update_from(&self, params: UpdateFromParams) -> Result<Vec<SqlPlan>>

Plan an UPDATE target SET ... FROM src WHERE ....

Returns Err(SqlError::Unsupported) for engines that cannot participate as an update target in a cross-table update (timeseries, kv-with-opaque-keys).

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fn plan_delete(&self, params: DeleteParams) -> Result<Vec<SqlPlan>>

Plan a DELETE (point or bulk).

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fn plan_truncate(&self, params: TruncateParams) -> Result<Vec<SqlPlan>>

Plan a TRUNCATE. Returns Err(SqlError::Unsupported) for engines that carry no whole-collection clear on the SQL surface (array).

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fn plan_aggregate(&self, params: AggregateParams) -> Result<SqlPlan>

Plan a GROUP BY / aggregate query.

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fn plan_merge(&self, params: MergeParams) -> Result<Vec<SqlPlan>>

Plan a MERGE statement.

Returns Err(SqlError::Unsupported) for engines that do not support MERGE semantics (everything except document_schemaless and document_strict).

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fn accepts_undeclared_columns(&self) -> bool

True when the engine accepts fields the schema never declares, so a read of an undeclared name resolves to NULL instead of raising SqlError::UnknownColumn.

Provided Methods§

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fn implicit_columns(&self) -> &'static [&'static str]

Columns every collection on this engine carries whether or not the DDL declares them. A reference to one resolves like a declared column.

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fn value_column_name_is_free(&self) -> bool

True when the engine stores one value whose column name the statement picks. Such a collection resolves any name while it declares no value column, and closes to the declared set once it names one.

Dyn Compatibility§

This trait is dyn compatible.

In older versions of Rust, dyn compatibility was called "object safety".

Implementors§