# Querying the Catalog to plan an upgrade

DevFeed: [Querying the Catalog to plan an upgrade](<https://devfeed.tech/articles/querying-the-catalog-to-plan-an-upgrade-34385.md>)

Original publisher: [Read original article](<https://tapoueh.org/blog/2010/08/querying-the-catalog-to-plan-an-upgrade/>)

Author: Dimitri Fontaine PostgreSQL Major Contributor; Author

Published: 2010-08-05T09:00:00Z

Content type: tutorial

Language: en

Sources: [Dimitri Fontaine](<https://devfeed.tech/sources/dimitri-fontaine.md>)

Topics: [PostgreSQL](<https://devfeed.tech/topics/postgresql.md>), [Databases](<https://devfeed.tech/topics/databases.md>), [Query (disambiguation)](<https://devfeed.tech/topics/query.md>), [hash](<https://devfeed.tech/topics/hash.md>), [upgrade](<https://devfeed.tech/topics/upgrade.md>)

Tags: [database](<https://devfeed.tech/tags/database.md>), [hash](<https://devfeed.tech/tags/hash.md>), [postgresql](<https://devfeed.tech/tags/postgresql.md>), [query](<https://devfeed.tech/tags/query.md>), [upgrade](<https://devfeed.tech/tags/upgrade.md>)

## AI overview

This tutorial explains how to query PostgreSQL system catalogs to identify hash indexes on interval columns when planning a minor upgrade. It also shows how catalog queries can generate commands or scripts to rebuild affected indexes.

## Source excerpt

Some user on IRC was reading the releases notes in order to plan for a minor upgrade of his 8.3.3 installation, and was puzzled about potential needs for rebuilding GIST indexes. That's from the 8.3.5 release notes, and from the 8.3.8 notes you see that you need to consider hash indexes on interval columns too. Now the question is, how to find out if any such beasts are in use in your database?