This will vary depending on the issue for which the intervention is required in the first place.
When both Validation and Production are at the same SOLABS QM version number and an intervention is required at the database level: the Production database will be restored over the Validation database only if the problem does not exists in Validation. If the issue is also found in Validation, the intervention will be done directly.
If the intervention impacts the core files, since both are at the same version, the intervention will also be done in Validation directly.
On the other hand, in the unlikely situation where Validation and Production are not at the same version number and an intervention is required for an issue impacting Production, then both the Production's core files and database will be restored over Validation (though a backup of the Validation environment will be done and restored after the intervention is completed).
Note that this is only a basic guideline, which, as stated, is subject to be evaluated on a per case basis, depending on the issue, the impact of the intervention, etc.