Module project 

Attribute projection over a sparse tile.

Drops attribute columns the caller doesn’t need. Coordinates and per-dim dictionaries are preserved; only attr_cols and the MBR’s attr_stats are subsetted. The output schema (with the same subset of attrs in the same order) must be produced by the caller; this operator does not mutate schemas.

Structs

Projection

Ordered subset of attribute indices into schema.attrs. Duplicates are allowed (lets callers fan out a column) but each index must be in range.

Functions

project_sparse

Build a new tile carrying only the projected attribute columns. proj is validated against tile.attr_cols.len() (the tile’s own attribute count, not a schema), so the operator is schema-free.