# Handling Time-Variant DAGs with Constraints in Postgres

DevFeed: [Handling Time-Variant DAGs with Constraints in Postgres](<https://devfeed.tech/articles/handling-time-variant-dags-with-constraints-in-postgres-5322.md>)

Original publisher: [Read original article](<https://neon.com/blog/handling-time-variant-dags-with-constraints-in-postgres>)

Author: Thorsten Rieß

Published: 2025-10-20T16:34:49Z

Content type: article

Language: en

Sources: [Blog -- Neon Docs](<https://devfeed.tech/sources/blog-neon-docs.md>)

Topics: [Graphs](<https://devfeed.tech/topics/graphs.md>), [Database](<https://devfeed.tech/topics/database.md>), [Serverless](<https://devfeed.tech/topics/serverless.md>), [Code](<https://devfeed.tech/topics/code.md>), [Open Source](<https://devfeed.tech/topics/open-source.md>)

Tags: [code](<https://devfeed.tech/tags/code.md>), [community](<https://devfeed.tech/tags/community.md>), [data](<https://devfeed.tech/tags/data.md>), [database](<https://devfeed.tech/tags/database.md>), [graphs](<https://devfeed.tech/tags/graphs.md>), [open-source](<https://devfeed.tech/tags/open-source.md>), [postgres](<https://devfeed.tech/tags/postgres.md>), [serverless](<https://devfeed.tech/tags/serverless.md>)

## AI overview

The article explains how traconiq models time-variant directed acyclic graphs for vehicle-fleet attachments in Postgres. It describes database constraints for preventing cycles and invalid relationships, temporal validity intervals for changing attachments, and priority-based resolution of conflicting data from manual input, GPS, and automated sensors. The implementation uses Neon serverless Postgres, with full code available as open source.

## Source excerpt

Managing dynamically changing directed acyclic graphs (DAGs) with constraints in Postgres enables robust tracking of relationships that evolve over time. At traconiq, this pattern is central to how we manage our vehicle fleet, where trucks and trailers attach and detach constantl...