{"id":"count-is-barrier","text":"`Count` stage materializes its entire input into a `defaultdict` before yielding any output, making it a pipeline barrier that forces all upstream stages to complete first","truth_value":"IN","source":"entries/2026/05/29/batch-word-count-pipeline.md","source_url":"","source_hash":"","justifications":[],"dependents":["materialization-barriers-span-storage-and-processing","pipeline-stages-hide-materialization-barriers"],"metadata":{},"created_at":"","updated_at":"","reviewed_at":"","verified_at":"","retracted_at":"","explanation":{"steps":[{"node":"count-is-barrier","truth_value":"IN","reason":"premise"}]}}