Construct a manifest-backed row-sharded source

row_sharded_source() presents compatible child sources as one logical observation-by-feature array. Stable shard IDs and explicit boundaries make global-to-local row routing inspectable and serializable. Reads are grouped by touched shard, so an arbitrary ordered selector is issued at most once to each selected child.

Usage

row_sharded_source(sources, shard_ids = NULL, shard_data = NULL)

Arguments

sources

A non-empty list of compatible two-dimensional array sources.

shard_ids

Stable, unique shard identifiers.

shard_data

Optional scalar metadata with one row per shard. Names used by the shard manifest are reserved.

Value

A serializable row_sharded_source.

Examples

shards <- list(
  memory_source(matrix(1:4, nrow = 2)),
  memory_source(matrix(5:8, nrow = 2))
)
src <- row_sharded_source(shards)
source_shape(src)
#> [1] 4 2