FAQ: Why does the size of the geodatabase not decrease after deleting its contents?
Why does the size of the geodatabase not decrease after deleting its contents?
As data is added and edited within a geodatabase, its size increases to accommodate the data. The space occupied by a personal or file geodatabase does not decrease after deleting its contents, (for example, tables, feature classes, rasters, or raster pyramids) because the occupied space on the disk drive is associated with the geodatabase and not the geodatabase contents.
The space that is not being used can be reclaimed by compacting the geodatabase, which can be done through the Compact tool in ArcToolbox or by right-clicking the geodatabase in ArcCatalog and selecting the 'Compact Database' option. For more information, please review the help documentation linked in the Related Information section of this article.