When users are accessing the AutoCAD Plant 3D or AutoCAD P&ID projects from the network server, some data is cached locally. This is done primarily to improve performance of the application in areas where the data is not expected to change frequently.
It is always recommended to back-up the project and it’s drawings. The process to restore a backed up project in very straight forward, just copy the backed up project to original location using Windows explorer. There is no extra step required if you are restoring the project on your local machine. If you are restoring the project to a network location in the same folder as the original project was, then after copying the project, it is necessary to clear the Persistent Local Data Cache (PLDC). This is necessary because the local data chance still has data from old/original project that might not be relevant to the restored project. To clear PLDC, you have to run the PnPLocalDataCachePurger.exe tool. This tool is installed on your system while installing either AutoCAD Plant 3D or AutoCAD P&ID to the install root folder (default location on Windows XP will be C:\Program Files\Autodesk\AutoCAD Plant 3D 2011).
Purging the local data cache will not delete, remove or corrupt your projects and the cache will rebuild again as soon as a particular project is opened. You can also consider running this tool when you see low disk space on your C drive. This will purge the local cache, so that you can release disk space usually used by completed projects. After PLDC has been cleaned, opening the project and drawing may take longer than usual as the cache will have to be re-built. Usually it will be the first time project is being used after PLDC purge.
This will be a very useful tip for users accessing project on the network.