# Per-worker, and global, IO bandwidth in explain plans

DevFeed: [Per-worker, and global, IO bandwidth in explain plans](<https://devfeed.tech/articles/per-worker-and-global-io-bandwidth-in-explain-plans-33676.md>)

Original publisher: [Read original article](<https://www.depesz.com/2026/02/21/per-worker-and-global-io-bandwidth-in-explain-plans/>)

Author: depesz

Published: 2026-02-21T13:24:57Z

Content type: article

Language: en

Sources: [select \* from depesz;](<https://devfeed.tech/sources/select-from-depesz.md>)

Topics: [PostgreSQL](<https://devfeed.tech/topics/postgresql.md>), [IO](<https://devfeed.tech/topics/io.md>), [parallel](<https://devfeed.tech/topics/parallel.md>)

Tags: [analyze](<https://devfeed.tech/tags/analyze.md>), [execution](<https://devfeed.tech/tags/execution.md>), [explain](<https://devfeed.tech/tags/explain.md>), [explain-depesz-com](<https://devfeed.tech/tags/explain-depesz-com.md>), [io](<https://devfeed.tech/tags/io.md>), [parallel](<https://devfeed.tech/tags/parallel.md>), [plan](<https://devfeed.tech/tags/plan.md>), [postgresql](<https://devfeed.tech/tags/postgresql.md>), [speed](<https://devfeed.tech/tags/speed.md>), [timing](<https://devfeed.tech/tags/timing.md>), [uncategorized](<https://devfeed.tech/tags/uncategorized.md>), [worker](<https://devfeed.tech/tags/worker.md>)

## AI overview

This article explains how PostgreSQL explain plans can report per-worker and global I/O bandwidth during parallel execution. It describes how summed worker timings differ from wall-clock time and introduces an exclusive-time bandwidth figure for the disks' total workload.

## Source excerpt

Jeremy Schneider suggested a change to how plans are displayed - adding another bit of information in case we have timing information for IO for explain node. Took me a while to research, but it finally made it's way... Let's consider this simple plan. In it's Parallel Seq Scan node we see: -> Parallel Seq ... Continue reading "Per-worker, and global, IO bandwidth in explain plans"