[Bug]: Redundant index oc_filecache.fs_parent

⚠️ This issue respects the following points: ⚠️

• This is a bug, not a question or a configuration/webserver/proxy issue.
• This issue is not already reported on Github OR Nextcloud Community Forum (I've searched it).
• Nextcloud Server is up to date. See Maintenance and Release Schedule for supported versions.
• I agree to follow Nextcloud's Code of Conduct.

Bug description

create index fs_parent
    on nextclouddev.oc_filecache (parent);

create index fs_parent_name_hash
    on nextclouddev.oc_filecache (parent, name);

• the database can use fs_parent_name_hash for any operation it would have used fs_parent
• INSERT and DELETE have to maintain both indices
• UPDATES of parent have to both indices

Steps to reproduce

1. Install Nextcloud

Expected behavior

Efficient use of database indices

Installation method

None

Nextcloud Server version

master

Operating system

None

PHP engine version

None

Web server

None

Database engine version

None

Is this bug present after an update or on a fresh install?

None

Are you using the Nextcloud Server Encryption module?

None

What user-backends are you using?

• Default user-backend (database)
• LDAP/ Active Directory
• SSO - SAML
• Other

Configuration report

No response

List of activated Apps

No response

Nextcloud Signing status

No response

Nextcloud Logs

No response

Additional info

No response

No file or test is named. Start by locating the schema or migration definitions for oc_filecache and the fs_parent and fs_parent_name_hash indexes, then inspect how index changes are handled across supported databases. Done means the redundant fs_parent index is no longer created while the useful composite index remains and database behavior is preserved.