Summary: Add support for an "anti-selector" or NOT IN logic in CDC event selectors to allow querying all changes except those matching a given set of criteria (e.g., excluding specific properties, labels, operations, etc.). Problem Statement: Currently, the CDC query system allows users to include specific changes via detailed selectors (e.g., filter by labels, changesTo, operation, etc.). However, there is no built-in way to express negative filtering or exclusion—such as querying for all changes except updates to certain properties or nodes with specific labels. This limitation forces users to either: Post-process results client-side to remove undesired changes, or Construct overly complex selectors to include every other desired case. This results in inefficiency, verbosity, and increased client-side logic. Proposed Feature: Introduce support for negation or anti-selectors in the CDC selector format. This could be achieved through an explicit "exclude" or "not" keyword, or extended support for NOT IN logic within fields like "labels", "changesTo", and "operation". Example syntax 1 — using "exclude": { "select": "n", "exclude": { "labels": ["SystemLog", "Audit"], "changesTo": ["lastSeen", "sessionToken"], "operation": ["u"] } } Example syntax 2 — using NOT IN logic: { "select": "n", "labels": {"NOT IN": ["SystemLog", "Audit"]}, "changesTo": {"NOT IN": ["lastSeen", "sessionToken"]}, "operation": {"NOT IN": ["u"]} } Use Cases: Exclude noisy audit logs or system entities from streaming pipelines. Avoid processing frequent but low-value property changes (e.g., lastAccessed, viewCount). Simplify subscriptions to business-relevant changes while ignoring background updates. Reduce downstream filtering overhead in real-time processing or analytics systems. Benefits: Enhances expressiveness of CDC query language. Reduces unnecessary computation and data transfer. Enables clearer, more maintainable CDC queries. Aligns with standard filtering capabilities found in query languages like Cypher and SQL. Requesting Teams / Roles Impacted: Data engineering teams building CDC pipelines. Developers consuming real-time changes via db.cdc.query. Users of Neo4j Aura, Enterprise, and dedicated cloud environments. Conclusion: Adding a negation or anti-selector mechanism would be a valuable enhancement to the CDC query API. It improves query flexibility, simplifies data processing workflows, and enables more targeted use of CDC in production environments. We would greatly appreciate consideration of this feature in a future Neo4j release.
