GeoServer does not come built-in with support for Pregeneralized Features; it must be installed through an extension.
Installing the Pregeneralized Features extension¶
Download the Pregeneralized Features extension from the GeoServer download page.
Make sure to match the version of the extension to the version of the GeoServer instance!
Extract the contents of the archive into the WEB-INF/lib directory of the GeoServer installation.
Adding a Pregeneralized Features data store¶
If the extension is properly installed, Generalized Data Store will be listed as an option when creating a new data store.