The uploadstash table has multiple fields that appears to be never used, only written to in UploadStash::stashFile (https://gerrit.wikimedia.org/g/mediawiki/core/+/d02602c59cc31bb36f668acae64f6ba3f0201deb/includes/upload/UploadStash.php#297)
us_orig_path - codesearch: https://codesearch.wmcloud.org/search/?q=us_orig_path&i=nope&files=&repos=
us_sha1 - codesearch: https://codesearch.wmcloud.org/search/?q=us_sha1&i=nope&files=&repos=
Can the columns be removed?
Removing the DBA tag for now as there are no action point for us.
Once if it is found if the columns can be dropped, please feel a Schema-change-in-production ticket (https://wikitech.wikimedia.org/wiki/Schema_changes#Workflow_of_a_schema_change)
Not sure which team own uploadstash table definition.
They are both loaded into UploadStash::$fileMetadata. Before touching the database, that should be removed first (probably with a deprecation process as they are part of a public method's return value) and if that doesn't break anything they can be dropped.
They certainly don't seem useful - us_orig_path is just the path to the tempfile that got copied into the stash, and the sha1 is already part of us_props and that's where the upload code reads it from, and having a sha1 DB field for the stash doesn't seem terribly useful, as the stash is per-user so there is little point in checking for duplicates.