--- title: "A Guide to Downsampling Time Series Data with InfluxDB 3" url: https://daily.dev/posts/a-guide-to-downsampling-time-series-data-with-influxdb-3-gszfikvcz source_url: https://www.influxdata.com/blog/downsampling-guide-influxdb-3 type: article source: "InfluxData" published: 2026-08-19T07:14:24.864Z updated: 2026-08-19T07:14:53.776Z tags: ["python", "sql", "influxdb"] reading_time: 9 upvotes: 0 comments: 0 language: en --- > ## Documentation Index > Fetch the complete documentation index at: https://daily.dev/llms.txt > Use this file to discover all available pages before exploring further. # A Guide to Downsampling Time Series Data with InfluxDB 3 **[InfluxData](https://daily.dev/sources/influxdb)** · 9 min read · 0 upvotes · 0 comments ## Summary A hands-on tutorial covering two ways to downsample time series data in InfluxDB 3: query-time aggregation using SQL's DATE_BIN function, and persisted downsampling using the Python Processing Engine's official downsampler plugin. Using a bird-tracking telemetry simulator, it walks through generating sample data, writing DATE_BIN queries for on-the-fly rollups, configuring a scheduled downsampler trigger with proper offset handling to avoid partial aggregates, validating the reduction with SQL comparisons, and troubleshooting common failure causes. It closes with production best practices around interval selection, tag preservation, and offset tuning. ## Full article daily.dev links to this article rather than hosting it. Read it at the original source: ## Questions this post answers ### How do I downsample time series data in InfluxDB 3 using SQL? Use the DATE_BIN function in a SELECT query to bucket timestamps into fixed intervals, then group by that bucket along with any tags you want to preserve, such as species and name. For example, DATE_BIN(INTERVAL '10 seconds', time) combined with AVG, MIN, MAX and COUNT aggregates produces summarized rows without writing them to another table or reducing stored raw data. _daily.dev surfaces practical database tutorials for engineers building time series pipelines._ ### Why would a scheduled downsampler plugin produce partial or incomplete aggregate rows? Partial aggregates happen when the downsampler queries the newest time bin before all writes for that bin have arrived, which can occur if the data generator and the downsampler run on the same scheduler boundary with no offset. Setting an offset (e.g. offset=10s) delays the queried window so the newest bin has already closed, ensuring the expected number of source points are present before aggregation. _Engineers debugging scheduled rollup jobs can track these gotchas alongside daily.dev's database coverage._ ### How can I verify that a downsampling job in InfluxDB 3 correctly represents the raw source data? Compare a fixed, completed time interval between the raw table and the downsampled table rather than checking whether the target table merely contains rows, since active writes can skew counts during validation. Confirm that raw row counts equal the summed record_count from the downsampled rows, and compute a row_reduction_percent to quantify the reduction before shortening raw-data retention. _daily.dev helps engineers validating data pipelines stay current on database tooling and practices._ ## Similar posts on daily.dev - [Use the Downsampling Plugin in InfluxDB 3](https://daily.dev/posts/use-the-downsampling-plugin-in-influxdb-3-eeowcnwpg) · InfluxData · 0 upvotes · 0 comments - [AI-Powered Spacecraft Operations with InfluxDB 3](https://daily.dev/posts/ai-powered-spacecraft-operations-with-influxdb-3-yq6xnb3oz) · InfluxData · 1 upvotes · 0 comments - [Generate Synthetic Time Series Data in InfluxDB 3](https://daily.dev/posts/generate-synthetic-time-series-data-in-influxdb-3-qbjdxlpcb) · InfluxData · 0 upvotes · 0 comments - [What’s New in InfluxDB 3: 5 New Processing Engine Plugins](https://daily.dev/posts/what-s-new-in-influxdb-3-5-new-processing-engine-plugins-bwpyp2p5e) · InfluxData · 0 upvotes · 0 comments - [Master the Basics of InfluxDB 3 with These Two Free Courses](https://daily.dev/posts/master-the-basics-of-influxdb-3-with-these-two-free-courses-louqw7l7p) · InfluxData · 0 upvotes · 0 comments --- Tags: [#python](https://daily.dev/tags/python), [#sql](https://daily.dev/tags/sql), [#influxdb](https://daily.dev/tags/influxdb) [View this post on daily.dev](https://daily.dev/posts/a-guide-to-downsampling-time-series-data-with-influxdb-3-gszfikvcz)