---
title: "All Your GUCs in a Row: config_file"
url: https://daily.dev/posts/all-your-gucs-in-a-row-config-file-53spmxdlx
source_url: https://postgr.es/p/9kS
type: article
source: "Planet PostgreSQL"
published: 2026-05-31T07:44:27.510Z
updated: 2026-05-31T09:27:58.531Z
tags: ["backend", "postgresql"]
reading_time: 2
upvotes: 0
comments: 0
language: en
---

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# All Your GUCs in a Row: config_file

**[Planet PostgreSQL](https://daily.dev/sources/planet-postgresql)** · 2 min read · 0 upvotes · 0 comments

## Summary

PostgreSQL's `config_file` parameter has a unique bootstrap paradox: it tells the server where to find `postgresql.conf`, but cannot itself be stored in that file. It can only be set via the `postgres` command line using `-c config_file=/path/to/postgresql.conf`. The most practical use of `config_file` is reading it via `SHOW config_file` to determine which configuration file the running server actually loaded — critical when edits seem to have no effect, often because you're editing the wrong file. Different Linux packaging systems (RPM vs Debian/Ubuntu) place `postgresql.conf` in different locations, making this command essential. Three companion parameters — `data_directory`, `hba_file`, and `ident_file` — handle other startup locations, with `hba_file` and `ident_file` allowed inside `postgresql.conf` since the bootstrap paradox doesn't apply to them.

## Full article

daily.dev links to this article rather than hosting it. Read it at the original source: <https://postgr.es/p/9kS>

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---

Tags: [#backend](https://daily.dev/tags/backend), [#postgresql](https://daily.dev/tags/postgresql)

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