> ## Documentation Index
> Fetch the complete documentation index at: https://docs.cognite.com/llms.txt
> Use this file to discover all available pages before exploring further.

# About the Cognite PI AF extractor

> Learn about the Cognite PI Asset Framework extractor and how it connects to OSIsoft PI AF to extract elements and their attributes and unit-of-measure classes into the CDF staging area (RAW).

The extractor builds a hierarchy for each PI AF element in RAW, or you can configure the extractor to [create a flat structure in RAW](/cdf/integration/guides/extraction/configuration/piaf). You can filter the PI AF elements you want to extract using [PI queries](https://docs.osisoft.com/bundle/af-sdk/page/html/pipoint-query-syntax-overview.htm).