# Window Functions example

DevFeed: [Window Functions example](<https://devfeed.tech/articles/window-functions-example-34394.md>)

Original publisher: [Read original article](<https://tapoueh.org/blog/2010/09/window-functions-example/>)

Author: Dimitri Fontaine PostgreSQL Major Contributor; Author

Published: 2010-09-09T14:35:00Z

Content type: tutorial

Language: en

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

Topics: [SQL](<https://devfeed.tech/topics/sql.md>), [Query (disambiguation)](<https://devfeed.tech/topics/query.md>), [ordering](<https://devfeed.tech/topics/ordering.md>), [function](<https://devfeed.tech/topics/function.md>)

Tags: [function](<https://devfeed.tech/tags/function.md>), [ordering](<https://devfeed.tech/tags/ordering.md>), [partitioning](<https://devfeed.tech/tags/partitioning.md>), [query](<https://devfeed.tech/tags/query.md>), [sql](<https://devfeed.tech/tags/sql.md>), [window-functions](<https://devfeed.tech/tags/window-functions.md>)

## AI overview

This tutorial demonstrates how SQL window functions can identify changes in a column by comparing ordered rows with preceding values. It also discusses an initial false change and how to accommodate it.

## Source excerpt

So, when 8.4 came out there was all those comments about how getting window functions was an awesome addition. Now, it seems that a lot of people seeking for help in #postgresql just don't know what kind of problem this feature helps solving. I've already been using them in some cases here in this blog, for getting some nice overview about Partitioning: relation size per "group". *That's another way to count change* Now, another example use case rose on IRC today. I'll quote directly our user here: