Function index_dataflow

src/clusterd-test-driver/src/dataflow.rs:457–480

Build a single-index dataflow over a persist shard. Thin sugar over [`DataflowBuilder`] for the common shape: import the collection backed by `shard` as `source_id`, set `as_of`, and export an index `index_id` arranging the collection by `key_cols`. `shard_upper` is the exclusive upper bound of the shard's written data; see [`PersistSource::upper`].

(
    source_id: GlobalId,
    index_id: GlobalId,
    shard: ShardId,
    location: PersistLocation,
    desc: RelationDesc,
    key_cols: Vec<usize>,
    as_of: Timestamp,
    shard_upper: Timestamp

/// `shard_upper` is the exclusive upper bound of the shard's written data; see
/// [`PersistSource::upper`].
pub fn index_dataflow(
    source_id: GlobalId,
    index_id: GlobalId,
    shard: ShardId,
    location: PersistLocation,
    desc: RelationDesc,
    key_cols: Vec<usize>,
    as_of: Timestamp,
    shard_upper: Timestamp,
) -> anyhow::Result<DataflowDescription<RenderPlan, CollectionMetadata>> {
    let mut builder = DataflowBuilder::new("headless-index");
    builder.import_persist(
        source_id,
        PersistSource {
            shard,
            location,
            desc,
            upper: shard_upper,
        },
    );
    builder.as_of(as_of);
    builder.export_index(index_id, source_id, key_cols);
    builder.finish()
}

/// Build a dataflow that counts the rows of an existing index and exports the
/// count as a new, peekable index.