Module query 

Query structure types: projections, sort keys, aggregates, windows, engine/join/spatial enums.

Structs

AggregateExpr

Aggregate expression: COUNT(*), SUM(amount), etc.

SortKey

Sort key for ORDER BY.

WindowSpec

Window function specification.

Enums

AggOutputSlot

Records SELECT-list interleaving of GROUP BY keys and aggregate expressions so the output-schema builder emits columns in the user’s SELECT order instead of a hardcoded group-keys-first order. GroupKey(i) indexes Aggregate::group_by[i]; Aggregate(j) indexes Aggregate::aggregates[j]. Empty = no projection was in scope when the plan was built (engine-rules base plan); output_schema falls back to group-keys-first, matching pre-fix behavior.

EngineType

Database engine type for a collection.

JoinType

SQL join type.

Projection

Projection item in SELECT.

SpatialPredicate

Spatial predicate types.