---
title: "Why Does a PostgreSQL Query Slow Down as the Table Grows?"  
description: "Why Does a PostgreSQL Query Slow Down as the Table Grows?"  
author: "Gabriela Gómez"  
published: 2026-10-16  
canonical: https://answers.mindstick.com/qa/117678/why-does-a-postgresql-query-slow-down-as-the-table-grows  
category: "Mix Category"  
tags: ["PostgreSQL", "Databases", "Performance Tuning"]  
reading_time: 1 minute  

---

# Why Does a PostgreSQL Query Slow Down as the Table Grows?

A report query that used to finish quickly has become noticeably slower as one of our PostgreSQL tables has grown. The query filters on a [date range](https://www.mindstick.com/forum/162199/i-only-need-to-convert-gmail-emails-from-a-particular-date-range-to-word-how-can-i-do-that) and joins two related tables; it hasn’t changed, but the data volume has.

What would you inspect first to tell whether this is an indexing problem, a query-plan change, or something else? I’m trying to understand how to read **PostgreSQL query plans** when the same query behaves differently at different table sizes.


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Original Source: https://answers.mindstick.com/qa/117678/why-does-a-postgresql-query-slow-down-as-the-table-grows

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