What obsolete files can I remove from my iPhoto Library? I've been using iPhoto since many versions ago ... probably since version 1. In that time, the file structure of its iPhoto Library has changed a few times, and I suspect that some of the files in there now are no longer needed. I'd like to clean it up to save disk space. Do you know if the following are needed?


The root level of the iPhoto Library contains some folders named after years, from 1998-2006. Each folder contains subfolders for months and days, and each day folder contains a data folder and then two numbered files, one with no extension and one with the .attr extension. These files are only about half a kilobyte in size and appear to contain metadata only. It looks like a version upgrade in 2006 made these obsolete since they're all older than that.
A Caches folder contains two files with long alphanumeric names, last modified in 2009.
A Contents folder contains a PkgInfo file, last modified in 2008.
An Auto Import folder is empty, last modified in 2008.
A Dir.data file, last modified in 2008.
Files named Library.data, Library.iPhoto, Library6.iPhoto and Library6.iPhoto.back, last modified in 2009.
A ThemeCache file, last modified in 2010.


It seems pretty clear these are no longer used; I could always delete them and find out, since I have a backup. But maybe someone who started using iPhoto after 2009 can tell me if any of these files are in their library?
It is a bad idea to try to manually modify the folder structure inside the iPhoto library, as you seem to want to do.

The best way is to follow Apple's instructions for rebuilding the iPhoto library.

However, this is usually only used as a repair procedure if iPhoto is malfunctioning.

You can try this, but make sure you have a complete backup of your iPhoto library before you start the rebuilding procedure.

Also, realize that iPhoto has an internal Trash that is separate from Mac OS X's Trash. If you have deleted hundreds of photos over the years, and never emptied the iPhoto Trash, those photos will still be in there and taking up space in the file structure.