When you browse a folder with Windows Explorer, all the access to metadata is done directly from the files. There is no caching mechanism, other than a temporary cache for each folder view. Browsing a local, or remote shared, folder imply that the metadata extraction process is repeated each time, and so a file in a shared folder will be accessed by the local property handler (in our case, and for PDF files, the PDF property handler provided by the PDF-ShellTools) by transferring the acceded file bytes locally. And extracting metadata from PDFs is already a relative slow process, even for local files.
But Windows Explorer can speed up some of that file arranging/sorting functionality if the operation is carried from a
library. Libraries are able to use the windows search index database to query for the files metadata, and so can arrange and sort the files much more fast. That's why a remote shared folder can only be added to a library if that same folder is also
indexed at the remote PC.
When the shared folder is accessed from a library, things like views generated by the
arrange by functionality are really fast.
But even from libraries, specially if you are browsing a specific folder, the access to metadata is again directly from the file. Only fancy operations, such as the arrange by and search operations (and maybe some other) use the database.
Obviously, this is not a PDF-ShellTools problem. Blame Microsoft for this.
But take note that your problem may be related to something else, and you may use the PDF-ShellTools manager to disable the property handler to be sure.
