Function validate_sink_cluster 

pub(super) fn validate_sink_cluster(
    fqn: &FullyQualifiedName,
    stmt: &Statement,
    main_offset: usize,
    errors: &mut Vec<ValidationError>,
)

Validates that a sink specifies a cluster.

Sinks in Materialize must specify which cluster they run on using the IN CLUSTER clause. This ensures deterministic deployment and avoids implicit cluster selection.

Example

Valid:

CREATE SINK sink IN CLUSTER quickstart FROM table INTO ...;

Invalid:

CREATE SINK sink FROM table INTO ...;  -- missing cluster