The DB software being used isn’t stated, but if this is a DB dump, that’s perhaps done with DB tool help?
If this is SQL Server, people have found it does a bit more somehow (it’s slower), but details aren’t known. Basically I think it’s VSS copy though. I guess your DB software can produce things like incremental .bak?
Generally files are compressed, however known compressed file extensions aren’t, as there’s no point.
compression-extension-file controls this, if you have a need for special control for file extensions in use.
You could probably do that, but one question would be how many you’d need to get back for a database restore. Duplicati backups and restores are a point-in-time view, so if the .bak files are indistinguishable, finding out which ones to get may be hard. If they have different names, you still need to gather them all.
Nice scenario is there is a folder full of .bak with different names, and new files every so often to backup. Previously present files would be seen to be backed up already, so only the new files would be uploaded. Presumably, at some point the backup scheme resets, and does a full backup, but I don’t know your DB.
It’s not my call on what the developers prioritize, but you can see there’s a whole lot in the issue backlog. With far too few development volunteers, you might be in for a long wait to fix an issue with workarounds. Mine looks to be not quite accurate (I don’t use PowerShell), but web search will find some better details.
How to Use a Batch File to Make PowerShell Scripts Easier to Run was helpful because it points out that
PowerShell is not associated to the .PS1 file extension by default.
Geek School: Learn How to Automate Windows with PowerShell which it links suggests security benefits.
My Windows 10 system in Settings “Choose default apps by file type” gives my .pl and .ps1 associations:
so possibly you could make .ps1 actually run PS, but a security review might prefer that you didn’t do that.
There’s also a chance that it still wouldn’t work at the necessary low level, but only in places like cmd.exe.
I’m sorry you’re kind of stuck with Windows limitations, and no current Duplicati way to work around them.