An overview of the File Geodatabase toolset

To reduce storage requirements, you can compress vector file geodatabase feature classes and tables to a read-only format. Files can reduce to as little as 1/4 their original size. Once compressed, a dataset looks the same in ArcCatalog and ArcMap as when it was uncompressed. Also, apart from editing, you work with it the same way. The compressed data is a direct access format, so you do not have to uncompress it each time you access it: ArcGIS and ArcReader read it directly.

Tool	Description
Compact	Compacts a personal or file geodatabase. Compacting rearranges how the geodatabase is stored on disk, often reducing its size and improving performance.
Compress File Geodatabase Data	Compresses all the contents in a geodatabase, all the contents in a feature dataset, or an individual stand-alone feature class or table.
Uncompress File Geodatabase Data	Uncompresses all the contents in a geodatabase, all the contents in a feature dataset, or an individual stand-alone feature class or table.

Tools in the File Geodatabase toolset