Pulse Documentation

name: op-agg-null-count
description: Count records where the field is null. The inverse of a non-null count.
kind: operator
category: AGG
operator: AGG_NULL_COUNT
type: reference
applies_to: process, compose, predict
examples_tags: [data-quality, streaming-friendly]

Use when

Number of rows where a field has no value, over all rows or per group.

Questions it answers:

• How many respondents skipped the income question?
• Which regions have the most orders missing a delivery date?

Use something else:

• AGG_COUNT when you want the rows that do have a value.
• FILTER_NULL when you want to keep or drop the rows with no value.

Params

None.

Inputs

Output

Scalar int64 — count of null inputs. Per-group when wired under a grouper.

Components

Floor only — no operator-specific keys. Universal {n, n_null} per response-components contract.

• Mergeability: Mergeable
• Streaming: per-chunk; orchestrator sums

Gotchas

• Field must be nullable in the schema; non-nullable fields always return 0.
• Set-typed empty mask is NOT a null — distinct from missing.

See

• pulse_examples_search tags=[data-quality]
• Skills: aggregation-design, cohort-schema-design, response-components