If you allow end users to upload files to your APEX application you may have a lot of "orphaned" files in apex_application_files and not even realize it.

Orphaned files are files that exist in APEX_APPLICATION_FILES that are not associated with an application. This can happen for several reasons, the most common are:

• Files uploaded in Shared Components that aren't associated to an application
• End users uploading files then purposely keep them in APEX_APPLICATION_FILES
• End users uploading files and an error occurs

You can easily identify orphaned files using the APEX_APPLICATION_FILES view:

SELECT *
  FROM apex_application_files
 WHERE flow_id = 0 -- flow_id is the same as application_id

All 3 situations listed above will result in the file uploaded with flow_id = 0. The last 2 points, files uploaded from end users, can result in files that you may no longer need. I don't recommend that you keep uploaded files in the APEX_APPLICATION_FILES view. Instead you should move them immediately to a custom table. The main problem comes from the third point. When a user uploads a file and a validation fails. In this situation the file is uploaded to APEX_APPLICATION_FILES and then the validation fails. Even though the validation failed, the file still resides in APEX_APPLICATION_FILES. The following screen shot demonstrates this issue. [ To resolve this issue, I run the following application process which automatically "tags" uploaded files with a flow_id of -1\. By doing so you can run a nightly process to delete any files that have a flow_id of -1. Application Process: AP_TAG_APEX_FILES Sequence: -100 Point: On Submit: After Page Submission - Before Computations and Validations

-- AP_TAG_APEX_FILES
BEGIN
   FOR x IN (SELECT v (item_name) item_name_value
               FROM apex_application_page_items
              WHERE application_id = :app_id
                AND page_id = :app_page_id
                AND display_as = 'File Browse...')
   LOOP
      UPDATE apex_application_files aaf
         SET aaf.flow_id = -1
       WHERE aaf.NAME = x.item_name_value;
   END LOOP;
END;